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CBMicro

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What is an exotoxin?
Toxic proteins secreted by bacteria and released outside of the cell
Bacteria have both sexual and asexual cycles.
True
Name the microorganism associated w/ the following: Ergot poisoning, Zearalenones in corn, Patulin, Aflatoxin
Ergot poisoning= Claviceps purpurea; Zearalenones in corn= Fusarium graminarium; Patulin= Penicillium eseparsum; Aflatoxin= Aspergillus flavus
Which bacterial toxin is heat-stable and commonly associated with rice dishes?
Bacillus cereus emetic toxin.
What flame retardant was mixed in with cattle feed in Michigan causing contaminated dairy products?
PBB
Ascending paralysis is most often related to which pathogen and disease?
Campylobacter jejuni, Guillain-Barre syndrome
Define 'incubation period'.
The interval of time between infection by a microorganism and the onset of the 1st signs/symptoms of the disease.
Which of the following molds has a foot cell: Aspergillus, Penicillium, or Alternaria?
Aspergillus.
What are the two words represented by the acronym HACCP?
Hazard Analysis Critical Control Point
What four genera of molds can cause rotting in fresh fruits?
Aspergillus, Penicillum, Alternaria, Botrytis, rhizopus, monilinia, Colletotrichum, Fusarium, Cylindrocarpon, Mucor, Cladosporium
What bacterial structure provides resistance to heat and desiccation?
Endospore
What color are Staphylococcus aureus colonies on Baird Parker agar?
Black.
In the US the legal processing for low-acid foods requires what?
exposure to temps for a period equal to 12 D values fo C. botulism
you should not attempt to eat insects if you are already allergic to what?
Shellfish
Which mycotoxin is commonly associated with peanuts and corn?
Aflatoxin.
Optimum temperature for thermophiles is...
131-152 degrees F
What is the name of a polypeptide antibiotic produced by some Lactococcus lactis strains?
Nisin
What type of parasite will not survive if it is not living on a host plant?
Obligate parasite
Which organisms commonly grow in tomato juice blends that are not acidified?
Bacillus coagulans
Name names three intrinsic factors and three extrinsic factors that affect microbial growth in food products.
Intrinsic: water activity, pH, nutrient content; Extrinsic: temperature, storage environment, humidity.
What specific preservative is produced by Lactococcus lactis?
Nisin
what compound commonly used in transformers for heat dissipation was feared to be extremely carcinogenic?
PCB (polychlorinated biphenyl)
What is the number of equivalent minutes at 121 C delivered to a container of product calculated using a z value of 10 C known as?
F or sterilization process equivalent time
What toxin causes acute liver damage?
Aflatoxin
Can Clostridium botulinum grow at 0°F?
No
What is perigo factor?
Formation of a substance or an agent which is ten times more inhibitory to Clostridium spp than nitrate alone when medium with added nitrite is heated is called perigo factor (named after the microbiologist Perigo, J A).
Name the yeast that is considered probiotic.
Saccharomyces boulardii
The ability of an organism to survive thermal processing is termed what?
Heat resistance
What toxin is related to " Turkey X Disease " ?
Aflatoxin
The first outbreak occured on Vegan Cheese made from Cashew is
Salmonella stanley
What is the most common way to avoid a foodborne illness?
Wash hands
Baird parker mediums are used to detect and enumerate which organism or groups of organisms?
Staphylococcus aureus or staphylococci
Name the microorganism associated with Ergot poisoning.
Claviceps purpurea
On what food stuff is the mycotoxin patulin most commonly produced on?
Apples
Name three metabolic products of heterofermentative microorganisms.
Acetic acid, ethanol, formic acid, and CO2
Which form of mercury is associated with sea food toxicity?
Methyl or organic mercury
In 2008, the author of Modern Food Microbiology, currently in its 7 revision, passed away. Who is this author?
James Jay
What is the primary purpose of retorting low aci canned foods?
Reduce spores of C. bot by 10^12
Which microorganisms make the following hydrocolloids? Xanthan gum, curdlan, gellan gum
Xanthan - xanthomonas campestris, curdlan - alcaligenes faecalis var. myxogenes, gellan - pseudomonas elodea
Koch's postulates to determine disease causing microbes
(1) The microorganism must be found in diseased but not healthy individuals; (2) The microorganism must be cultured from the diseased individual; (3) Inoculation of a healthy individual with the cultured microorganism must recapitulated the disease; (4) The microorganism must be re-isolated from the inoculated, diseased individual and matched to the original microorganism.
Why is listeria monocytogenes of greater concern in refrigerated foods than in foods stored at ambient temperature?
L. m. is a psychrotroph that selectively grows at low temperatures
What does "TA" mean in regards to spoilage of canned food?
Thermophilic anaerobic
What is the incubation period for Listeria monocytes?
3-70 days
What are lactic acid bacteria?
A group of Gram+, non-spore forming, catalase negative, aerotolerant anaerobes, which carry out the fermentation of sugars
What microorganism does Oxford agar select for?
Listeria monocytogenes
Sanitation and inspection recommendations for adoption by state and local regulatory agencies for inspection of food retail and food service facilities are in the ________
FDA Food Code
What are zygospores?
Sexual spores of molds, formed by the union of the tips of 2 hyphae.
Give characteristics of Clostridium Botulinum.
A bacteria found in foods that produces toxins that are harmful when consumed. Very heat resistant, won't grow in acidic foods
Which genus of bacteria are used in the production of kimchi?
Leuconostoc gelidum, Weissella koreensis, and Lactobacillus sakei
The process in which a gaseous insecticide is released into a sealed building is known as WHAT?
Fumigation
Name a class 2b carcinogen found in corn.
Fumonisin
Yeast and mold are both fungi
True
Name one chemical compound that is used to sanitize food processing equipment.
NaOCL and quats
What genus/species of bacteria does the McBride Agar select for?
Listeria Monocytogenes
What is the "F" value?
Minutes required to destroy a given number of microbes at a given temperature
What does TSA stand for?
Trypticase Soy Agar
Name the common method used to detoxify aflatoxin in corn.
Treatment with ammonia
Name the foodborne pathogen that has the highest mortality rate.
Vibrio vulnificus (50% fatality rate) (also Clostridium botulinum (untreated) and certain Prion diseases)
What is the genus and species of the organism responsible for red tide?
Karenia brevis
What toxin-producing Gram-positive cocci can cause illness within 60 minutes of eating contaminated food?
Staphylococcus aureus
What toxic pigment is found in cottonseed endosperm?
Gossypol (it is removed during the oil refining process)
What are 2 types of microbiological testing used to identify and verify microorganisms in foods?
culture media, immunoassay, or polymerase chain reaction.
a microbial population of 3,000 CFU/ml that is exposed to a 2D process will theoretically have a final population of what?
30 CFU/ml
explain bacterial soft rot.
Spoilage caused by Erwinia carotovora and Pseudomonas marginalis. They break down pectins, giving a soft mushy consistency, bad odor at times in foods like carrots, onions, garlic, etc.
What is the most common pathogen found in outbreaks related to cheese?
L. monocytogenes
Name 3 molds that cause spoilage in vegetables.
Alternaria, Penicillium, Fusarium, Aspergillus, Rhizopus
Which mold (genus only) is a major concern for microbiological spoilage in commercially produced bread?
Rhizopus (Rhizopus stolonifer is the full name)
The USDA-FSIS currently (2008) recognizes high-pressure processing as an acceptable food safety intervention for eliminating which food pathogen from processed meat products?
Listeria monocytogenes
What is an indicator organism in food microbiology?
An indicator of sanitary conditions
What yeast is used in soy sauce production?
Zygosaccharomyces rouxii and/or Torulopsis spp.
Which pathogen is commonly associated with garlic in oil?
Clostridium botulinum.
Raw, unroasted cashews, are considered inedible sue to their containment of what toxin?
Urushiol
What is the term that identifies microorganisms that grow in low oxygen conditions?
Anaerobic
In relation to bacterial cultures, give the full form of the acronym ATCC.
American Type Culture Collection
What does SMAC stand for?
Sorbitol MacConkey
Name 3 foodborne pathogens that are responsible for more than 75% of human deaths caused by known pathogens in the US.
Salmonella, Listeria, and Toxoplasma. Followed by norwalk-like viruses, campylobacter, and E. coli O157:H7
Aflatoxin is produced by a mold.
True
What organism has the highest heat tolerance?
Clostridium botulinum.
How is fungi differentiated from algae and other higher plants?
It lacks chlorophyll
What is the order of heat resistance for microorganisms?
Bacterial spores are more heat resistant than bacterial vegetative cells, yeast cells, and molds.
Name two conditions under which yeasts and molds will outcompete most bacteria.
Low Aw (0.6-0.7) and pH <4 or >9
A food product with an initial population of 1X10^10 organisms was given a heat treatment of 5D values. What is the bacterial population after heating?
10^5.
Name the spore-forming anaerobic bacterium that is the concern in improperly processed canned goods and can produce a neurotoxin.
Clostridium botulinum
Which of the following is not a microbial preservative? (1) Nisin (2) Sodium Propionate (3) Sodium Alginate (4) Nitrite
Sodium Alginate.
What form of mercury is associated with seafood toxicity?
Org Hg or methyl Hg
How many infections of C. Botulism is required to be considered an outbreak?
2
Which microbial toxin is associated with improperly canned foods?
Botulinum toxin
What is a food infestation?
Presence of pests (insects or rodents)
From what source was Clostridium botulinum first isolated?
Smoked ham
What organism is responsible for Q fever and is more heat resistant that Mycobacterium tuberculosis?
Coxiella burnetii
The fungus Claviceps purpurea produces a group of toxins that cause: A. turkey X disease, B. ATA, C. diarrhea and vomiting, or D. ergotism
D. ergotism
What are sclerotia?
Dense, tightly packed masses of molds; they are survival structures (singular:sclerotium)
Which foodborne pathogen is more of a concern in ground meat than solid-muscle meats such as steaks?
Escherichia coli
Sporeforming aerobic rods occur as what?
Psychrotrophs, Mesophiles, and Thermophiles.
Which specific spore-forming bacterium is associated with the danger of swollen cans in low-acid foods?
Clostridium botulinum
What nutrient gel made from seaweed is used as a base for tiny plants generated using tissue culture techniques?
Agar
Clostridium botulinum growth can be inhibited under what pH?
4.6
Name 4 of the 6 primary pathotypes of pathogenic E. coli that cause diarrhea.
Diffuse-adhering (DAEC), enteropathogenic (EPEC), enterotoxigenic (ETEC), Enteroinvasive (EIEC), Enterohemorrhagic (EHEC), Enteroaggregative (EAEC)
What does EHEC stand for?
Enterohemorrhagic Escherichia coli
What is the form of aflatoxin excreted in milk?
M1
In August of 2020, there was a multi-state outbreak of Salmonella enterititis in which fruit?
Peaches
At what pH can a food be called an acid food?
A pH of at or less than 4.6
How do microbial inhibitors work?
By acting on the whole cell, cell wall, or cell membrane in order to interfere with the genetic mechanism of the cell, interfering with the enzyme systems of the cell, or by binding to essential nutrients to kill the cell or stop reproduction.
What is F value?
The number of minutes required to kill a known population of microorganisms in a given food under specified conditions.
Define and explain D-value.
The value of heat resistance. The specific time at a specific temperature for a specific food to destroy 90% of the population (one log) of a specific MO.
what Japanese dish composed of raw tuna is often implicated in foodborne illness outbreaks?
Sashimi
What animal is associated with the TSE disease Chronic Wasting Disease?
Chronic Wasting Disease= deer
Which Aflatoxin is the most carcinogenic? a. B1, b. G1, c. G2, d. M1
a. B1
What is the F Value in microbial death kinetics?
Lethality - the time in minutes required to bring about a required log reduction in target microbial population at a defined temperature.
Formula to calculate D-value.
D = t/(log N0 - log Nf); D = D-value, t = time, N0 = initial population, Nf = final population
What are teratogenic agents?
Compounds that could induce or cause birth defects or developmental malformations
What are some viruses that cause foodborne human illness?
Hepatitis, rotavirus, norovirus
What popular pesticide was banned in 1972 due to its negative effects on humans and birds?
DDT
Sneeze guards are placed on salad bars to protect the food from which pathogen?
Staphylococcus aureus
What does LAL stand for?
Limulus amebocyte lysate.
What does the acronym IMViC stand for and what is it used for?
The Indole, Methyl Red, Voges-Proskauer, Citrate tests. To divide Enterobacteriaceae into 2 major groups; the E. coli group and the Enterobacter-Klebsiella group
What class of microorganism causes swelling of cans upon heating?
Clostridium thermosaccharolyticum
What agents in Hektoen Enteric Agar differentiates Salmonella from Shigella?
Ferric ammonium citrate and sodium thiosulfate; they combine to detect the desulfhydrase enzymes by salmonella (enzyme converts thiosulfate to H2S, which then reacts w/ferric iron to create a black precipitate
What does ASM stand for?
American Society for Microbiology
List 5 genera of bacteria and molds that produce antimicrobial agents.
Penicillium ,L. lactis, Lactobacillus, Pediococcus,Streptomyces
In the development of toxicity data for seeking approval of a new food additive, explain the difference between an LD50 and NOAEL and what are the typical units for these?
LD50 is the dose that kills 50% of test animals;NOAEL is the highest dose that cause No Observed Adverse Effects Level; amount is mg or micrograms per kg body weight
The FDA and the AMI recommend cooking hamburger to ___°F, and increase from ___°F, to ensure destruction of E. coli O157:H7.
155°F, 145°F
What type of bacteria besides Staphylococci aureous can survive on cows utters?
Micrococci
The finest light microscope equipped with an Abbe refractometer can be used to observe viruses
False
Which medium is used to detect and enumerate Staphylococcus aureus directly in foods? A. apt agar, B. Baird-Parker agar, C. Potatoe dextrose Agar, D. Violet red bile agar
B. Baird-Parker Agar
The local Health Department reported salmonella. Which one of the following is a practice that could result in an outbreak of salmonella?
Cooked chicken is cut on the same board used to cut the raw chicken.
Name the mold responsible for soy sauce.
Aspergillus oryzae
Who developed the first formula to determine lethality during thermal processing?
Ball and Olsen
How is the cell wall structure of a Gram+ and Gram - cell responsible for the cell's Gram-stain reaction?
G+ bacteria have a very thick cell wall consisting of peptidoglycan or murein. These are dehydrated by the alcohol, causing the pores to close, thus preventing the Crystal Violet-Iodine complex from leaving the cell. In Gram -, cells have a thin peptidoglycan layer surrounded by an outer membrane. The alcohol dissolves the Outer Membrane and the thin peptidoglycan layer cannot retain the dye.
Which organisms does MacConkey Agar select for and what is the mechanism?
MacConkey Agar selects for Gram Negative Bacteria. MacConkey agar contains lactose, which allows differentiation based on the organsim's ability to ferment lactose. If an organism can ferment lactose, the agar will turn pink.
What organism is used in the manufacture of blue cheese?
Penicillium Roqueforti and Penicillium Glaucum
What microorganism does Baird-Parker agar select for?
Staphylococcus aureus
Most food borne pathogens of genus Vibrio will not grow unless the growth medium contains at least 0.5% concentration of what?
Salt concentration
Another name for thermal resistance constant is?
z-value
what bacterial genus is responsible for ropiness in bread?
Bacillus subtilis and Bacillus mesentericus
Juice or beverage spoilage by Alicyclobacillus primarily leads to what spoilage compound, associated with a medicinal off odor?
Guaiacol
What are the intrinsic and extrinsic factors for microbial growth in food?
Intrinsic: pH, water activity, redox potential, biological structure, moisture content,animicrobial component , competitive microflora, nutrient content Extrinsic: temperature and time, relative humidity, gaseous environment, presence of other organisms, processing operations, type of packaging
What pathogen is most commonly associated with ready-to-eat deli meats?
Listeria monocytogenes.
In the 2022 Food Code by FDA what term is used for items that usually relate to general sanitation, operational controls, sanitation standard operating procedures (SSOPs), facilities or structures, equipment design, or general maintenance?
Core Item.
What science deals with the harmful effects of chemicals on humans?
Toxicology
In sauerkraut production, salt promotes the growth of what group of bacteria?
Lactic acid bacteria
What is the genus and species of Koji mold?
Aspergillus oryzae
a recent outbreak of E. coli linked to Taco Bell restaurants was initially blamed on green onions, but the FDA later found that the source of the outbreak was not green onions, but was actually from what?
Lettuce
Work done between 1895 and 1898 by Underwood and Prescott.
Time-temperature combinations for various canned foods to remove spoilage microorganisms. Thermal processing for canning.
Which bacterium is commonly associated with listeriosis?
Listeria monocytogenes
what does the acronym NARMS stand for?
National Antimicrobial Resistance Monitoring System
Describe the differences between spores and vegetative cells.
Vegetative cells are metabolically active and relatively heat-sensitive. Spores are dormant, highly resistant to heat, chemicals, and desiccation, and are critical food safety concerns due to their survival through processing.
What does SPC stand for in microbiology?
Standard plate count
What are the name of bacterial viruses?
Bacteriophage
Another name for thermal death time is?
F value or sterilization value
What type of microorganism are quaternary ammonium (QUAT) compounds most effective against?
Gram positive bacteria
What are facultative anaerobes?
Microorganisms that can grown and survive with or without oxygen
Where in the US are C. botulinum type A, B, and type E generally found?
Type A: Common in the Western US (soil). Type B: Common in the Eastern/Mid-Atlantic US (soil). Type E: Common in Northern/Aquatic environments (sediment/fish).
Steam table disease is caused by consumption of meat dishes adequately cooked but held at 50-55 degrees C for several hours. the causative agent is _____________.
Clostridium perfringens
When was E. coli O157:H7 first linked with serious food born illness and what was the food product?
1982, hamburger, during investigation of 2 outbreaks of bloody diarrhea in Oregon and Michigan
What does RODAC stand for?
Replicate Organism Detection and Counting
When was Listeria monocytogenes first recognized as foodborne pathogen?
1981 (first case of illness in humans was in 1929)
What are psychrotrophs?
Psychrotrophs are cold-tolerant bacteria or archaea that have the ability to grow at low temperatures, but have optimal and maximal growth temperatures above 15 and 20°C, respectively.
What is the most common pathogen found in cheese outbreaks?
Monocytogenes
At what temperature are bacterial spores destroyed?
250 F
What end product(s) are produced in homofermentation?
Homofermentation is when bacteria produce mostly lactic acid
Give the name and type of food borne illness where the pathogens are consumed, take up residence in the intestinal walls and produce a toxin inside the body, and give an example
Food toxicoinfection.. E. coli O157: H7
What do the following microbiological acronyms mean? REA, MPN, SPC
REA: Restriction Enzyme Analysis, MPN: Most Probable Number, SPC: Standard Plate Count
a recent pet food recall took more than 60 million cans off the shelf and sickened pets across the country. What chemical was found in the contaminated pet foods?
Melamine
What can cause swelling in cans?
Thermophilic spore-formers (like Clostridium thermosaccharolyticum) or leaker spoilage (where bacteria enter through a faulty seam post-processing)
what does the abbreviation related to shellfish toxin DSP stand for?
DSP is Diarrheic Shellfish Poisoning
Which organisms does the Hektoen Enteric agar differentiate and how do the colonies appear?
Differentiates Salmonella and Shigella from other Enterobacteriaceae, Salmonella: Blue-green colonies with black centers (H2S production).Shigella: Green to blue-green colonies without black centers.Coliforms (like E. coli): Large, yellow to salmon-orange colonies
What animal is associated with the TSE disease Scrapie?
Goat
Name the 4 steps of the Fight BAC program.
Clean, Separate, Cook, Chill
What is the minimum internal cooking temperature for poultry recommended by the USDA?
165°F (74°C)
Difference between eukaryotic and prokaryotic?
Absence of a nuclear membrane and membrane-bound organelles in prokaryotes
Name the toxic substances in unprocessed cassava roots.
cyanogenic glycosides (lenamaric, lotaustralin)
Why are plates for total plate count incubated upside down?
To prevent condensation from dripping on the surface of the agar.
Major tests for allergies
RAST, Basophil Histamine Release, Skin test, Oral challenge, Immunoblotting.
what disease is Mycobacterium tuberculosis thought to contribute to?
Crohn's Disease
What four chemicals involved when conducting a Gram stain?
Crystal violet, iodine, alcohol-acetone, safranin
Explain why a virus cannot cause a toxicoinfection or an intoxication.
Viruses are obligate parasites;they do not produce toxins and can only cause invasive infections
Sneeze guards are placed on salad bars to protect food from which of the following; campylobacter jejuni, escherichia coli, salmonella, staphylococcus aureus?
Staph aureus
Give the genus/species of the organism used in processing Brie and Camambert cheeses what forms a white crust.
Penecillium Camembertii
What temperature do leftover foods need to be reheated?
165°F
Which pathogen is most commonly associated with post-processing contamination of ready-to-eat meats?
Listeria monocytogenes.
Boiling bacterial spores for 4 hours will destroy the spores.
False
What does GRAS stand for?
Generally Recognized as Safe
Why was Schwan's ice cream recalled from the marketplace in October of 1994?
For presence of Salmonella Enteriditis.
What stops the growth of salmonella but does not kill it?
Freezing and refrigeration
There are more than 2500 serotypes of Salmonella.
True
What is the selective agent in the following medium: proteose peptone?
Sodium Azide.
In a foodservice establishment, the function of an air curtain is to: a) form a shield of air that flying insects avoid; b) keep freezer and refrigerator temperatures constant; c) serve as a substitute door in the receiving area; d) prevent cockroaches and mice from entering the facility
a) Form a shield of air that flying insects avoid
Name the five genera of lactic acid bacteria.
Lactobacillus, Lactococcus, Leuconostoc, Pediococcus, Streptococcus
Bonus: What poison classes are in the following foods: rhubarb, potato, almond, cassava
Rhubarb: oxalic acid, Potato: solanine and chaconine, Almond: amygdalin and prunasin, Cassava: linamarin and lotaustralin
In general, microbial survival curves follow what type relationship?
First-order exponential
What is the organism (genus) most commonly associated with food poisoning?
Salmonella
What is the name of micro-organism used as indicator of radiation effectiveness in foods?
Deinococcus radiodurans or Bacillus pumilus
Name five yeast fermented food products.
Beer, wine, bread, distilled spirits, kefir, kombucha, root beer
In a HACCP plan, an undeclared allergen contamination is considered as what type of hazard?
Chemical
What does obligate mean for microorganisms?
Absolute Requirements.
What do Z-values represent for a microbial population?
The temp required to change a D-value by one log (D is a decimal reduction time at a specific temperature)
What term describes the relationship between dose and the magnitude of a toxic response?
Dose–response relationship
Approximately what fraction of foodborne illnesses occur from food prepared and consumed in the home: A.1/4, B.1/3, C.1/2, or D.3/4?
C. 1/2
What is proteose peptone?
Is an enzymatic digestion of animal tissues. commonly used in the prep of culture media for the production of toxins, and in the fermentation industry for starter cultures. It is a highly nutritious source for the growth of a wide range of microorganisms
What is LD50?
The amount of an ingested substance that will kill 50% of a test sample. Expressed in milligrams of substance per kilogram of body weight.
Trichinosis is most commonly associated with which food product?
Pork
What does TSC agar stand for and what does it select for?
Tryptose Sulfite Cycloserine Agar is used to select for Clostridium perfringens
What bacterial form can survive boiling at 100 deg C for 30 minutes?
The spores
What is the D value of a microorganism that is decreased in population by a factor of 10 in 2 minutes?
Two
What is the D-value for Clostridium botulinum in the spore at 121 C?
0.21 min
Name the bacterium that is a common concern in deli meats and dairy, and is known for its ability to grow at refrigeration temperatures and cause listeriosis.
Listeria monocytogenes
Sauerkraut results from what kind of fermentation process?
Lactic acid
Name one of the key bacteria responsible for kefir.
Lactobacillus kefiranofaciens, Lactobacillus paracasei, Lactobacillus plantarum, Lactobacillus acidophilus, and Lactobacillus delbrueckii subsp. bulgaricus
According to the USDA, what are the three safe ways to thaw frozen foods?
Refrigerate, immersion in cold water, microwave thawing
Which consumer category is at the highest risk with Listeria monocytogenes and why?
Pregnant women (because it can cross the placental barrier, leading to miscarriage or stillbirth)
Which is more saturated, pork or beef fat?
Beef
What are some of the advantages of using the general method to calculate lethality?
Simple to perform, most accurate method as long as: temperature measurement is accurate, time interval is reasonable, and a proper integration method is chosen, is a good tool for process evaluation
What causes trichinosis?
It is a type of roundworm infection is acquired by eating Trichinella species larvae in raw or undercooked meat
To calculate the lethal effect of a thermal process, name the two needed items of information.
1) Thermal resistance characteristics of microorganisms (reaction rate constants, Z and F values) 2) Dependence of rate constants on temperature (temperature history).
What does BSE stand for?
Bovine Spongiform Encephalopathy
What does VTEC stand for in food safety?
Verocytotoxin-producing E. coli
Name 3 examples of seafood intoxications.
Scromboid poisoning, puffer fish toxin, ciguetera toxin, shellfish toxin
The quality assurance system called HACCP stands for ...
Hazard Analysis Critical Control Points
Please rank the size of bacilli, cocci and helicoidal bacteria.
Helicoidal>bacilli>cocci
Why are enrichment techniques used when examining food for the presence of salmonella?
Salmonella re usually present in small numbers. Enrichment allows salmonella to grow and outcompete non-salmonella microbes and also allows recovery of injured cells
Trichinosis is caused by Trichinella spiralis; what class of microorganism is this?
Nematode
What term is used to describe a compound that is foreign to biological systems?
Xenobiotic
Lists the five steps, in proper sequence, for cleaning and sanitizing food equipment.
Pre-rinse, wash, intermediate rinse, sanitize, air dry
Epidemiology is the study of infection of the epidermis or skin.
False
Describe the “danger zone” for bacterial growth in foods and its significance.
The temperature range of 40°F–140°F (4°C–60°C) where bacteria grow most rapidly; foods should not remain in this range for more than 2 hours to prevent foodborne illness.
what bacterial foodborne pathogen can tolerate the lowest water activity and the highest salinity?
Staphylococcus aureus
What is the expected spoilage agent of UHT sterilized milk?
Heat-stable enzymes that survive the sterilization process.
In the 2022 Food Code by FDA what is the term used for the application of cumulative heat or chemicals on cleaned food-contact surfaces that, when evaluated for efficacy, is sufficient to yield a reduction of 5 logs, which is equal to a 99.999% reduction of representative disease microorganisms of public health importance.
Sanitization.
What does xenobiotic mean?
It is a foreign compound found in an organism that is not normally expected to be present in it
BHA and BHT are common antioxidants. What do these acronyms stand for and how much of these are allowed by law to be used in foods?
BHA: butylated hydroxyanisole, BHT: butylated hydroxytoluene 0.01% of fat content individually or 0.02% of the fat content of the food (when 2 or more are used together)
What type of bacteria love high heat?
Thermophiles
What does LD50 mean?
The average amount of a drug, toxin, chemical substance/mixture or microorganism capable of killing 1/2 of the test animals exposed under specific test conditions. Median lethal dose (LD50) is commonly expressed in mg/kg, by oral intake or skin exposure.
what do the acronyms BSE and CJD stand for, what is the causitive agents for these diseases, and what animals do these 2 diseases afflict?
Both are prions;BSE=Bovine Spongiform Encephalopathy(cattle);CJD= Creuztfeld-Jakob Disease(humans)
Yakult is a Japanese probiotic yogurt-like product made by fermenting a mixture of skim milk and sugar. What organism is used in the fermentation of Yakult?
Lactobacillus casei
Which bacterium causes food poisoning known as 'fried rice syndrome'?
Bacillus cereus
What is an emerging infectious disease (EID)?
An infectious disease whose incidence has increased in the past 20 years and could increase in the near future
Define food infection.
Ingestion of organism which then produces toxin or infects cells causes illness
Name the microbial sources of commercial chymosin.
Escherichia coli, Aspergillus niger var. awamori, and Kluyveromyces lactis
What is the microbial gum commonly used in salad dressings?
Xanthan gum
Name three hazard classes identified by HACCP.
Biological, Chemical, Physical
Explain how water activity differs from moisture content and why it matters in food safety.
Moisture content measures total water present, while water activity measures the availability of water for microbial growth and chemical reactions. Foods with high moisture but low water activity (e.g., jams) may be shelf-stable, whereas foods with lower moisture but higher water activity may still support microbial growth.
Term used to describe a compound causing defects in growing featus?
Teratogen
What do these abbreviations related to shellfish toxins stand for? PSP, DSP, NSP, ASP
PSP = Paralytic Shellfish Poisoning, DSP = Diarrheic Shellfish Poisoning, NSP = Neurotoxic Shellfish Poisoning, ASP = Amnesic Shellfish Poisoning
Name the main microorganism used in malolactic fermentation.
Oenococcus oeni
When testing for C. perfringens, what is the only test result that is negative suggesting a positive confirmation of C. perfringens?
Motility
A pink color in sauerkraut indicates the presence of what?
Yeast
What are some disadvantages of using the formula (ball) method to calculate lethality?
Only can use at a constant retort process temperature, the cooling portion modeling is empirical and may over/under estimate lethality
Name three thermal calculation parameters that can be ascertained from a TDT curve.
Fo, F, Z, and D
What foodborne pathogen can cause peptic ulcers?
Helicobacter pylori
Name food borne pathogen that grows below 10 C.
Listeria Monocytogenes
Name the non-sporforming Gram positive bacterium that is most resistant to irradiation.
Deinococcus radiodurans
What organism is thought to contribute to Crohn's Disease?
Mycobacterium avium subsp. paratuberculosis (MAP)
How many general principles does HACCP involve? a) five; b) ten; c) seven; d) fourteen; e) eight
c) seven
Top 3 microbial causes of foodborne illnesses.
Norovirus, salmonella, clostridium perfringes
Psychrotrophs have the optimal growth temperature at 10C which is why they spoil refrigerated foods
False
Why is it important to not get meat juice or raw meats on other foods?
Because raw meat and meat juice has bacteria that can be easily spread to other foods, causing foodborne illness.
Trichinosis is caused by Trichinella spiralis; what type of organism is this?
A nematode
What spoilage organisms are most likely to be found vacuum packed, refrigerated meats held for several weeks?
Clostridium perfringens
The thermal inactivation of microorganisms and most nutrients obey which order of reaction kinetics?
First Order
What are the five major classes of micro organisms based on temperature?
Mesophile thermophile, psychrotroph psycrophile extremophiles
which fungus is responsible for producting the etiologic agents of aflatoxicosis?
Aspergillus flavus
Original root used for root beer that is not used anymore because of toxin?
Sassafras and safrole.
What is the source of natural toxins peculiar to shellfish?
Planktonic organisms
What is one of the molds that produces aflatoxin?
Aspergillus flavus and aspergillus parasiticus
What are the 5 major classes of microorganisms based on temperature?
Psychrophiles, psychrotrophs, mesophiles, thermophiles, hyperthermophiles
Define LD50 in the context of toxicology, and explain what a lower LD50 value indicates about the toxicity of a substance compared to a higher value.
LD50 stands for the Lethal Dose, 50%, which is the dose of a substance required to kill 50% of a test population. A lower LD50 value indicates that the substance is more toxic (or more potent), as a smaller dose is required to cause 50% mortality.
Which genera of bacteria can fluoresce and spoil fresh cut vegetables and meat?
Pseudomonas
Which of the following four choices do you need to include in developing a Standardized Recipe for a HACCP system? a) Critical Control Points; b) Cost Per Portion; c) Cooking Methods; d) Ingredients
A
Name 4 major causes of food spoilage.
Microbial growth, enzyme activity, insects, parasites, & rodents, temperature fluctuation, moisture fluctuation, air, particularly O2, light, time
What organisms produce a yellow colony on Mannitol salt plates?
Staphylococcus aureus
What is the term for bacteria that thrive in cold temperatures, such as those found in refrigeration?
Psychrophiles
Which type of Clostridium botulinum is associated with aquatic food products and is often psychotropic?
Type E
Name 6 of the 8 (or 7?) pathogenic types of botulinum toxin.
A, B, C1, C2, D, E, F, G
In which phase of their growth are bacteria most sensitive for destruction?
Log phase
A bacteria, yeast, fungi, or filamentous genetic material has been changed in nucleic aicd modification by FAO/WHO is termed what?
Genetically modified
In food safety, which temperature range is known as the "danger zone"?
40-140F
What are the long, branching filamentous structures which collectively make up the mycelium?
Hyphae
Name the toxin present in Tonka beans.
Coumarin (1-3%)
What bacteria is found in foods that produce harmful toxins, is heat resistant but won’t grow in acidic foods?
Clostridium Botulinum
What is the full form of DAL wrt food safety?
Defect Action Level
Give the genus and species of 3 molds that are used in the production of blue cheese.
Penicillium roqueforti, P. glaucum, P. gorgonzola and P. stilton
What does LPM agar stand for and what is it used for in food microbiology?
Lithium chloride Phenylethanol Moxalactam agar, a solid medium used to isolate and cultivate Listeria monocytogenes from food and dairy products
what are the selective agents of VRBA?
Bile salts and crystal violet
Eosin methylene blue agar is used for?
Lactose fermenting
What organism causes Typhoid Fever?
Salmonella typhi
What is the time required to achieve a specific reduction in microorganisms?
F value
A positive catalase test shows the formation of _______ when hydrogen peroxide is added.
Effervescence due to the in vitro Oxygen production
Extremophilic microbes are found in various environments. Name the extreme conditions associate with each types of microbes: Barophile; Halophile; Thermophile
Barophile: High pressure; Halophile - High Salt content; Thermophile: High heat/temperatures
Name three methods for the calculation of lethality.
General, formula (ball) method, and numerical
Give the genus and species of one microorganism for each of the following categories: gram negative, strict anaerobe, foodborne pathogen, sulfide spoiler
Gram negative= Salmonella typhimerium or E. coli; strict anaerobe= C. botulinum; foodborne pathogen= S. aureus, Listeria monocytogenes, Sulfide spoiler= Desulfotomaculum nigrificans
Name three key bacteria responsible for kefir.
Lactobacillus kefiranofaciens, Lactobacillus paracasei, Lactobacillus plantarum, Lactobacillus acidophilus, and Lactobacillus delbrueckii subsp. bulgaricus
Which fungal genus is the primary producer of Aflatoxins, commonly found in contaminated peanuts and corn?
Aspergillus
Define Lactic acid bacteria.
Gram-positive microorganisms known as the main safe industrial-scale producers of lactic acid (LA)
What are mycoses?
When molds and fungi colonize body surfaces. There are various types, categorized based on how deep into tissues they inhabit.
What is a bacteriophage composed of?
A nucleic acid molecule surrounded by a protein structure.
What are hyphae?
Filaments of molds
What is the full form of NSF?
National Sanitation Foundation
Which mycotoxin is produced by Aspergillus flavus?
Aflatoxin
What is the difference between commercial sterilization and pasteurization?
Sterilization: processed at temps higher than 100 C, mainly for canning (retorting), destroys all microbes that may cause spoilage (may contain heat resistant bacteria spores such as endospores or thermophiles or flat sour bacteria), shelf life of 2+ years at room temperature, pasteurization: processed at temps lover than 100 C, typically high temperature for short time (HTST), destroys pathogenic microbes, reduces spoilage microbes, inactivates enzymes
What is the time temperature combination required for foodservice operators to safely cool cooked foods?
Food must be cool to 70 degrees Fahrenheit within two hours, and then 41 within four hours, and the total cooling time should not exceed six hours.
In the human mouth, Streptococcus mutans converts sugar into what substance that causes tooth decay?
Lactic acid
What organism can cause symptoms similar to appendicitis?
Yersinia enterocolitica
Potassium sorbate can be applied to sausage casings before or after stuffing to retard what?
Yeast, Molds, and select bacteria
how much Hg is allowed in shark meat
1 ppm
What are three genera of fungi commonly used in food production?
Aspergillus, Penicillium, Fusarium, Saccharomyces
FSIS and CFSAN recommend cooking hamburger to what internal temp?
160 degrees F or 71 degrees C
Which of the following four choices is the first of seven elements of an effective Hazard Analysis Critical Control Points (HACCP), program in food processing? a. Monitoring critical control points; b. Establishing limits for the critical control points; c. Developing and implementing a verification system; d. Identifying potential hazards
d. Identifying potential hazards
The D-value in thermal processing represents the time required to destroy what percentage of a specific microorganism at a given temperature?
90% (or one log cycle)
Name 3 of the 16 gram negative, facultative anaerobic rods.
Escherichia (e.g., E. coli), Salmonella (Food poisoning, Typhoid), Shigella (Dysentery), Klebsiella (Pneumonia), Enterobacter (Opportunistic infections), Serratia (Produces red pigment), Proteus (Highly motile/swarming), Morganella, Providencia, Citrobacter, Edwardsiella, Yersinia (The Plague, Y. enterocolitica), Erwinia (Plant pathogens), Hafnia, Kluyvera, Cedecea
In reference to Aflatoxin B1, what does the B designate?
Blue fluorescence
Viruses contain both RNA and DNA in the core.
False
How many square centimeters in a standard Petri dish?
35 mm--area of 8.55 square cm. 50 mm or 5 cm--area of 19.60 square cm. 100 mm or 9 cm-- area of 56.75 square cm. 135 mm-- area of 143 square cm.
What animal is associated with the TSE disease Variant Creutzfeldt-Jakob Disease?
Human
List one of the three safe methods to defrost food.
Refrigerator thawing, cold water thawing, microwave thawing or (cooking without thawing)
Below what pH can Clostridium botulinum spores no longer germinate?
Below pH 4.6
Name 5 microorganisms that have been associated with food poisoning outbreaks.
C. botulinum, C. perfringens, B. cereus, S. aureus, Salmonella, Shigella, Vibrio parahaemolyticus, E. coli, Listeria monocytogenes
For what foods has irradiation been approved as a preservation method?
Poultry, pork and spices
What property does Aspergillus glaucus have that allows it to grow on dried fruit?
Xerophilic
What are the ingredients of TGY agar?
Trypton, glucose and yeast extract
What is used to pasteurize spices?
ethylene oxide or gamma radiation
What temperature range is commonly known as the “danger zone” for microbial growth?
40°F–140°F (4°C–60°C).
What seafood poisoning occurs when bacteria decarboxylate histidine to histamine?
Scombroid poisoning
Explain the difference between intrinsic and extrinsic factors affecting microbial growth in foods.
Intrinsic factors are inherent to the food, such as pH, water activity, nutrient content, and natural antimicrobials. Extrinsic factors include environmental conditions like storage temperature, relative humidity, and surrounding atmosphere.
Molds grow in an oxidation-reduction potential of...?
Positive Values.
What is the difference between Homofermentation and Heterofermentation?
Homofermentation is when bacteria produce mostly lactic acid; Heterofermentation is when bacteria produce lactic acid, butyric acid, acetic acid, Carbon Dioxide, and other end products.
What is the major assumption made when dealing with CFU in microbiology?
Each individual colony is originated from one original bacterial cell. All the cells within each colony forming unit is homogenous
This environmental toxin is most commonly associated with atmospheric deposition into water bodies, where bacteria convert its inorganic form into the highly toxic organic form, and it accumulates in contaminated fish.
Mercury
What is a mycotoxin?
Secondary metabolites produced by microfungi that can cause disease and death in humans and animals.
Which sugar alcohol used as a sugar substitute in human food products is extremely toxic to dogs?
Xylitol
In the MUG test, what enzyme from E. coli is being tested?
B-glucuronidase
How is the relative humidity related to water activity?
Water activity = relative humidity / 100.
What is the single most important phase of a sterile canning operation?
Retorting
What are the three spore-forming foodborne pathogens?
Bacillus cereus, clostridium perfringens, clostridium botulinum
What causes greening of luncheon type meats?
Lactobacillus Viridescens
Food-borne parasites in pork ,fish and fecal contamination
Trichinella spirosis (pork) Parasitic worm (fish) Entamoeba histolytica (fecal contamination)
Name the 10 states in the FoodNet active Surveillance Program.
Californa, Colorado, Connecticut, Georgia, Maryland, Minnesota, New Mexico, New York, Oregon, and Tennessee
What is the maximum ERH considered safe for grain storage?
70% (around 80% ERH moisture grain results in increased respiration and temperature increases)
Which organism caused the largest # of foodborne outbreaks and what type of general category of foodborne disease does it cause?
Norovirus; viral gastroenteritis/ viral infection
Which lactic acid producing bacteria found in sourdough bread takes its name from a California city?
Lactobacillus sanfranciscensis
What does BP-agar stand for?
Baird-Parker
In the 2022 Food Code by FDA what term is used for the cleaning and sanitizing of utensils and food-contact surfaces of equipment.
Warewashing
During which phase of microbial growth is bacteria the easiest to kill?
Log or exponential phase
Name four intrinsic and four extrinsic factors that affect microbial growth in foods.
Intrinsic: pH, water activity, nutrient content, natural antimicrobials Extrinsic: temperature, relative humidity, atmosphere (oxygen), storage time
Deoxynivalenol (Vomitoxin) is a toxin produced in foods which causes foodborne illnesses associated w/cereals, wheat, and cornbread. Give the genus and species of the organism that produces this toxin.
Fusarium graminearum
An initial population of 50,000 bacteria grows with a generation time of 30 minutes. About how many bacteria will be present 3 hours later?
3,200,000 [Nt= N0 * 2^(t/G)]
Vinegar is produced by anaerobic fermentation.
False
Many fungi are dimorphic. What does dimorphic mean?
They can change from a yeast form to a mold form
What is the genus and species of the bacteria that causes tuberculosis?
Mycobacterium tuberculosis
What toxic compound was once found in root beer?
Safrole, also known as shikimol
What bacterial neurotoxin is used for cosmetic procedures?
Botulism toxic
Another name for decimal reduction time is?
D-value
If the D value of the critical organism is four, and the product is a high acid food, what is the F value?
F = 5d = 20
Why is egg yolk used in the media for the isolation of Bacillus cereus?
To check for the lecithinase reaction.
Shigellosis is caused by the bacteria Shigella. What common practice can greatly reduce your chances of contracting Shigellosis?
Hand washing
What are the 2 types of food poisioning possibly received from consuming fish?
Ciguatera and scombroid. Scombroid is an intoxication (histamine), while Ciguatera is caused by ciguatoxins produced by dinoflagellates and bioaccumulated in fish.
What genus of bacteria does the Hektoen Enteric Agar select for?
Hektoen Enteric selects for Salmonella and Shigella
Which single bacteriocin is approved for food preservation in the US? Which product is it used in?
Nisin, for pasteurized cheese product.
What does XLD stand for?
Xylose Lysine Desoxycholate
Which microorganism is most commonly associated with botulism?
Clostridium botulinum.
what does the media DRBC stand for and what is it used to enummerate?
Dichloran Rose Bengal Chloramphenicol: yeasts and molds
What does MPN stand for in food microbiology?
Most Probable Number
Which pathogen is paid the most attention in anaerobically packed foods?
Clostridium botulinum
Which pathogen is often linked to unpasteurized apple cider?
E. coli O157:H7
A 6D process reduces the population of the target organism by what percent?
1
What is food infection?
Involve micro organism present in food at time of ingestion, they then grow in host and cause disease: E.G: C.perfrongens, Salmonella, shigella, vibrio parahaemolyticus, streptococcus pyogenes bacillus cereus, campylobacter jejuni
What do microaerophiles require for growth?
Some oxygen.
In a recent outbreak of foodborne illness in RTE meats by Bil Mar Foods resulted in a recall of 76 million pounds of product. Name the causitive agent and rare strain that was found in these products.
Listeria monocytogenes, 4b serotype
What type of microorganisms can grow in oxygen but prefer to grow in oxygen reduced environments?
Microaerophilic
Name the body of FAO-WHO that deals with food standards including pesticides.
Codex Alimentarius commission
Which bacterium is used in setting adequate heat treatment in canning industry to eliminate Clostridium botulinum?
Clostridium sporogenes PA 3679
In 1993, KSU food scientists were granted a patent for a rapid detection method applied to a foodborne pathogen. Name the enzyme which hastens detection and the organism.
Oxyrase TM; E. coli O157:H7
What is LD50 value?
Dose of a substance that will kill 50% of the test subjects
A characteristic of an "emetic" form is that it causes nausea but not ...
diarrhea
What is the major toxin-producing microorganism associated with herb infused oils held at or above room temp for extended periods of time?
Clostridium botulinum
What is the most common psychotropic bacteria associated with milk spoilage?
Pseudomonas species
What animal cause the most human deaths?
Mosquito
What does EIEC stand for?
Enteroinvasive Escherichia coli
How are bacteria grouped according to Bergey’s Manual?
Gram reaction, morphology (rod or cocci), based on phylogeny (evolutionary relationships) using 16S rRNA sequencing
What is CAMP and what does it test for?
An assay for Listeria monocytogenes; Christie Atkins Munch-Petersen
What are the 2 distinct syndromes of B. cereus gastroenteritis?
Vomiting (emetic) type, diarrhea type
Which Gram-positive, rod-shaped bacterium is a major concern in Ready-to-Eat (RTE) meats because it can grow at refrigeration temperatures?
Listeria monocytogenes
In predictive food micro, growth rate is calculated by linear or non-linear regression on 'log of counts vs. time plot'. which model cannot be used for calculating growth rate: A.logistic model, B. Arrhenius model, C.Gompertz model, D.baranyi model?
Arrhenius model
Name three pointers to avoid salmonella.
1. Wash your hands carefully before handling food. 2. Clean the cutting board and use a sanitizing solution, before and after use. 3. Heating foods to at least 155 F. 4. Refrigerate or freeze leftovers immediately. 5. Keep pet feeding dishes and toys out of the kitchen.
What is the most commonly occurring food allergy in infants and young children?
Cow's milk
Where was the first recorded outbreak of botulism and what was the source?
Germany (18th century) and Blood Sausage.
Discuss food allergens: Name the top 9 major food allergens in the U.S. Explain why cross-contact is a major concern. Describe one control measure in manufacturing.
Top 9 major food allergens in the U.S.: Milk, Eggs, Fish, Crustacean shellfish, Tree nuts, Peanuts, Wheat, Soybeans, Sesame Why cross-contact is a major concern: Even trace amounts can trigger severe allergic reactions; Can occur via shared equipment, utensils, or improper sanitation One control measure in manufacturing: Dedicated production lines; Validated cleaning procedures; Allergen labeling and employee training
Name 3 types of food deterioration.
Physical, chemical, biological
The D-value as a function of temperature has what type of relationship?
Linear
What does FSIS stand for?
Food safety and inspection service
Good manufacturing practice regulations of the FDA are subdivided into six categories. Name three of them.
Sanitation, Thermally processed low acid foods, Acidified foods, Cocoa products and confectionary, smoke and smoke flavored fish, frozen raw breaded shrimp.
What are the 2 principle mechanisms by which preservatives stop the growth of microorganisms?
Water availability and acidity
What are the two selected agents in Baird-Parker media?
Is a medium for the enumeration of Staphylococcus aureus in foods which was first reported by Baird-Parker (1962) contains Lithium chloride and tellurite
What is the main disadvantage of commercial sterilization of a food?
Significant changes in nutritive and sensory characteristics
How does Food irradiation kill pathogens?
The ionizing radiation sends enough energy into the bacterial or mold cells in the food to break chemical bonds.
Name three of the main antimicrobials used in aquaculture throughout the world.
Penicillins (like amoxicillin, ampicillin), phenicols (florfenicol), macrolides (erythromycin), tetracylcins (Oxytetracycline), aminoglycosides (streptomycin), sulfonamides, fluroquinolones
What is the most effective way of inactivating botulism toxin?
Heat
What time and temperature combo for food service operators to safely cool cooked foods?
7°C in 2 hours, 41°C in 4 hours
The enterotoxins produced by Staphylococcus aureus can withstand boiling.
True
Which common food borne bacterial pathogen is microaerophilic and requires temperatures above 32 degrees C for growth?
Campylobacter jejuni
In 1989, the pork industry began a national eradication program for what virus, which is nearing completion?
Pseudorabies
Describe aflatoxins and their source.
Aflatoxins are toxic secondary metabolites produced by Aspergillus flavus and A. parasiticus, commonly found in peanuts, corn, and other stored crops.
What is the term for an irreversible, non-cancerous lesion of the liver caused by chronic consumption of aflatoxins?
Cirrhosis
Name a halophilic food infectious bacteria
Except for V. cholerae and V. mimicus, all Vibrio species are halophilic (salt requiring) Example: Vibrio parahaemolyticus
What term describes the accumulation of fat-soluble toxins in organisms at higher trophic levels?
Biomagnification.
Green bean canning pathogen?
Botulinum.
Name six of the dirty dozen foods.
EWG 2025 list-Strawberries, spinach, (kale, collard and mustard greens), grapes, peaches, pears, nectarines, apples, cherries, blueberries, blackberries, potato
What is a secondary metabolite produced by fungi and can cause unnatural or "deleterious biological changes in plants, animals, humans, or microorganisms?
Mycotoxin
What is the 12D process?
The time/temperature process that will reduce the microbe spore population (typically C. bot) by 12 log cycles
Name one bacterium that is in the nodules of roots of leguminous plants.
Rhizobium
A bacteria commonly used to transform plants is what?
Agrobacterium tumefaciens.
what animal constitutes the single most common source of Yersinia enterocolitica in humans?
Pigs
Which bacteriocin is associated with Lactococcus lactis?
Nisin
what are the approximate annual estimates for numbers of foodborne illnesses and deaths in the US?
47.8 million illnesses, and 3000 deaths
Which bacteria must be tested for under the final rule for pathogen reduction and HACCP? And which bacteria should meet performance standards?
Generic E. coli, Salmonella
What is the value for the increase in temperature required to decrease the D value by a factor of 10 (or one log cycle reduction)?
z-value
Name the microorganism associated w/ Zearalenones in corn.
Fusarium graminearum
What are coliforms?
Aerobic to facultatively anaerobic Gram-negative, non-sporeforming rods that ferment lactose with the formation of gas within 48 hours at 35°C.
What does OSHA stand for?
Occupational Safety and Health Administration
HACCP procedures are now required by law for what foods?
Meat, poultry, seafood
What is the full form of SSOP?
Sanitation Standard Operating Procedure
What is the minimal water activity for most bacteria?
0.90-0.91
List all seven principles of HACCP, in order.
Conduct a hazard analysis Determine critical control points (CCPs) Establish critical limits Establish monitoring procedures Establish corrective actions Establish verification procedures Establish record-keeping and documentation procedures
Aflatoxins are NOT produced by: A.Aspergillus flavus, B. Aspergillus parasiticus, or C.Aspergillus chraceus
C.Aspergillus chraceus
The Ames test is used to identify which organism? a. E. coli b. Staph aureus c. Salmonella __? d. Salmonella typhimurium
D. Salmonella typhimurium
Explain the steps of a standard microbial plate count and how CFU/mL is calculated.
Serially dilute sample. Plate on agar medium. Incubate and count colonies (30–300 range). CFU/mL = (colonies × dilution factor) / plated volume.
Which of the following denotes the correct way to type the name of a bacteria genus and species: A.genus name and species name capitalized, B.genus name capitalized and species lower-case, C.genus and species both lower-case, or D.none of the above?
B. genus name capitalized, species name lower-case
name 4 bacteriocins produced by lactic acid bacteria and state the most thoroughly studied.
Nisin, pediocin, diplococcin, helveticin, and lactacin (nisin most thoroughly studied)
Which pathogen is most commonly associated with unpasteurized apple cider?
Escherichia coli O157:H7
What is the full name of MRS agar used for lactobacilli cultures?
De Man, Rogosa and Sharpe agar
What does HARPC stand for?
Hazard Analysis and Risk-based Preventive Controls
According to the World Health Organization, the genus of bacteria is the most common cause of human gastroenteritis in the world.
Campylobacter.
Name 3 food poisoning microorganisms present in seafood.
Vibrio cholerae, vibrio parahaemolyticus, vibrio vulnificus, yersinia ruckeri, aeromonas hydrophila, etc
Which bacterium from Vibrio genus is halotolerant and causes rice water stools and possible death from dehydration?
Vibrio cholerae
Name the 3 blotting techniques.
Southern - DNA; Northern - RNA; Western - protein
Name two organisms responsible for foodborne illness that tolerate relatively high salt concentrations.
Staphylococcus aureus, Listeria monocytogenes.
What is a bacteriophage?
A virus that infects bacteria.
What does NACMCF stand for?
National Advisory Council on Microbial Criteria for Foods
In determining the effect of combining two antimicrobials, what does a fractional inhibitory concentration index of 0.4 signify? A. Syngergy B. Partial synergy C. Indifference D. Antagonism
A. Synergy
What are psychrophiles?
Bacteria or archae that grow over the range of sub zero to 20 C with an optimum around 15 C
What is 'Minimal Botulinum Cook'; give both temperature and time.
250 degrees F for 3 minutes
How does the toxin of Clostridium botulinum work?
It interferes with the release or action of acetylcholine, leading to paralysis.
What are five mycotoxins, and what is one food each is commonly found in?
Aflatoxin- (peanuts, tree nuts, corn), Patulin- (apples), Roquefortine c (blue cheeses), Ochratoxin a (grain, pork, coffee, wine grapes), Citrinin (grains)
What three characteristics are commonly used to describe coliforms?
Rod-shaped Gram-negative nonspore forming and motile or nonmotile bacteria that can ferment lactose with the production of acid and gas when incubated at 35–37°C.
What is an indicator organism?
An organism used to test changes in water quality conditions or food microbiological analysis by detecting for the presence of harmful pathogens .
What is a biofilm?
A layer of microorganisms formed on the surface of foods that is highly resistant to standard sanitation.
What is the minimum internal cooking temperature for raw ground beef as recommended by the FDA for food service providers? (In Fahrenheit or Celsius)
155 F for 15 s
What are Xerophilic molds?
Dry Loving.
Ingestion of crickets may cause which type of allergen reaction?
Shell fish crustaceans
In September 2020, dried woodear mushroom were recalled because of which Salmonella serovar?
Salmonella stanley
Name two mycotoxins produced by Fusarium species.
Zearalonone, Trichothecenes, Fumonisins, and Fusarin.
What substance is used in microbiology for microscopes in order to reduce the influence of refractive index of air?
Immersion oil
Name the product category for which USDA/FDA has zero tolerance policy wrt Listeria monocytogenes.
RTE products
What is the minimum internal cooking temperature for raw ground beef as recommended by the USDA for consumers? (In Fahrenheit or Celsius)
160 F / 71 C
What is a mycelium?
A single mass of hyphae
Good manufacturing practice regulations of the FDA are subdivided into six categories. Name three.
Sanitation; Thermally processed, low-acid foods (packaged in hermetically sealed containers, including aseptic processing); acidified foods; cacao products and confectionery; smoked and smoke-flavored fish; frozen raw breaded shrimp
What is responsible for Bovine Spongiform Encephalopathy?
Proteins known as prions
What is food intoxication?
Involve toxic substances produced by micro-organisms in foods before consumption, toxins then cause disease after being ingested: staph aureus, C.botulinum, aspergillus flavus
What naturally occurring toxic substance, often found in the green parts of potatoes, is a glycoalkaloid?
Solanine
Given the highest dose of a chemical that causes no effect in rats is 300mg; what is the accepted daily intake for humans?
3 mg, (100 fold safety factor)
The critical events of infection by ingested virus appear to occur in: A.esophagus, B.stomach, C.small intestine, or D. large intestine
C.small intestine
What weekly report published by the Public Health Service contains all data on foodborne illnesses?
Morbidity and Mortality Report
What does E. stand for in E. coli?
Escherichia
Which is the most likely pH for dark cutting beef: 5.4, 5.9, or 6.2
pH 6.2
The organism responsible for making wine, beer, sauerkraut, and bread is Saccharomyces cerevisiae var. ellipsoides.
False
What is patulin, with what food products is it associated, and how is it usually analytically determined?
A mycotoxin formed by Penicillium, Aspergillus and Byssochlamys genera associated with apple juice products; determined by High Performance Liquid Chromatography
Which of the following ingredients are most responsible for myofibrillar protein solubilization during sausage processing? A.nitrite anderythorbate B.salt and phosphate C.glucono delta lactone and nonfat dry milk D.spices
B. salt and phosphate
Which describes a class 2 recall? a. minor violations not subjecto FDA action b. exposure but no health consequences c. exposure may cause health consequences d. reasonable use or exposure will causes serious health consequences
c. exposure may cause medically reversible health consequences
At which humidity level can bacteria better withstand- High or low?
Low
Arrange these foodborne pathogens in the increasing order of their approximate onset time of symptoms due to infection or intoxication: Listeria monocytogenes, Staphylococcus aureus, Clostridium perfringens, and Vibrio cholerae
Staphylococcus aureus (2-4hr), Clostridium perfringens (6-12hrs), Vibrio cholerae (18-36hrs), Listeria monocytogenes (1-30 days or more)
Botulism was given its Latin-derived name because it was associated with what food?
Sausage
Name three characteristics of Salmonella.
Gram negative, facultative anaerobe, catalase positive, oxidase negative, ubiquitous, lactose non-fermenting, H2S positive and cause foodborne illness
Microorganisms that can survive low water activity conditions are called
Xerophilic
Which protein in eggs has antimicrobial properties?
Lysozyme
Why is listeria monocytogenes of greater concern in refrigerated foods than in foods stored at ambient temperatures?
Listeria monocytogenes is a psychrotroph; it can grow at refrigeration temperature, but it actually grows faster at ambient/room temperature. It is of greater concern in the fridge because it lacks competition there, as most other pathogens are inhibited by the cold.
Define an "emerging pathogen".
Just recently recognized as a human pathogen
According to a 1999 CDC report on foodborne illness, almost all rates of infection by specific microorganisms decreased w/ the exception of which pathogen?
Salmonella
Which of the following pathogens is known for its ability to grow at 4 degrees Celsius:A.Clostridium botulinum, B.Escherichia coli, C.Camplobacter jejuni, or D.Listeria monocytogenes?
D.Listeria monocytogenes
What is zoonosis?
Transmittance of disease from vertebrates to humans
What is the likely source of the hemorrhagic e. coli that contaminates hamburger?
cow's cut during slaughter
In 1963 the FDA approval for a new processing method was given, only to be revoked in 1968. What was the product and the process?
Bacon and irradiation
What are flagella?
Appendages that allow microbes to be motile.
What food-borne parasite can be found in hogs eating uncooked food waste?
Trichinella Spiralis.
During which stage in the life cycle of cyclospora do oocyst become infectious?
Sporulated oocyst
Under FSMA, for how long must records be retained?
Under FSMA, records must be retained for at least 2 years
Protein coat of virus is called:
Capsid
What bacterium causes 'sweet curdling' type of spoilage of pasteurized milk without acid production:
Bacillus cereus
Name the mold responsible for Tempeh.
Rhizopus oligosporus
Explain the significance of D-value and z-value in thermal processing.
The D-value is the time required at a specific temperature to reduce a microbial population by 90%. The z-value is the temperature change needed to change the D-value by a factor of ten. Together, they are used to design and validate thermal processes to ensure microbial safety while minimizing quality loss.
Viruses specific to E. coli are: A.eshiphages, B.cytopathic phages, C.coliphages, or D.microphages
C.coliphages
What is the term for the infectious protein particles responsible for diseases like Mad Cow disease?
Prions.
Name one example of each of the following used in food and beverages industry: Fungi Yeast Mold Bacteria Single-cell food
Fungi: Actinomucor, Amylomyces, Mucor, Rhizopus, Monascus, Neurospora, Aspergillus, Penicillium, Candida, Endomyces, Hansenula, Saccharomyces, Torulopsis, Trichosporon, Zygosaccharomyces/ Just say mushrooms Yeast: Saccharomyces, Kluyveromyces Mold: Aspergillus, Penicillium, Rhizopus, Neurospora Bacteria: Lactobacillus, Lactococcus, thousands of names Single-cell foods: eggs, microalgae such as spirulina, chlorella
what is the color of typical Salmonella colony on EMB agar?
Transparent or amber/pinkish, but they specifically lack the dark centers or green sheen of lactose fermenters
What are the core messages of the five keys to safer food outlined by the World Health Organization?
Keep clean, separate raw and cooked, cook thoroughly, Keep food at safe temperatures, use safe water and raw materials
What is 4D reduction?
99.99%.
If the D value of the organism is 0.2, and the product is a low acid food, what would the F value be?
F = 12d = 2.4
Food poisoning results from: A.eating too fast, B.over-eating, C.undercooking of food or re-contamination after cooking, or D.overcooking food?
C. undercooking of food or re-contamination after cooking
Give the genus and species of the organism that produces xanthan gum.
Xanthomonas campestris
What is the primary microorganism used for leavening of bakery products?
Saccharomyces cerevisiae
A thermal death curve plots ___ against _____.
Temperature vs. time
With fermented cucumbers or cabbage, why is salt added?
To discourage the growth of Pseudomonas and enterobacteria
What pathogenic bacteria can grow at aw=0.86 ?
Staph Aureus
The bacterium Listeria monocytogenes is primarily a concern because of its ability to grow rapidly at what range of temperatures?
Refrigeration temperatures (Psychrotrophic)
What is the water activity to cause spoilage for bacteria, yeast, and molds?
Bacteria - 0.9, Yeast - 0.85-0.9, Mold 0.75-0.8
Describe the purpose of HACCP and list its first two principles.
HACCP is a preventive food safety system designed to identify, evaluate, and control hazards. The first two principles are hazard analysis and identification of critical control points (CCPs).
What does RV stand for?
Rappaport-Vassiliadis
You attend a party with several friends where a variety of hot and cold finger foods were served. The food tasted great, but on the way home a few of you complained of abdominal cramps. After a day of cramps and diarrhea, you feel fine. A possible cause for your symptoms is:
Staphylococcus aureus
What is the genus of bacteria most often linked to botulism?
Clostridium.
What does the abbreviation related to shellfish toxin PSP stand for?
PSP is Paralytic Shellfish Poisoning
what does the abbreviation related to shellfish toxin ASP stand for?
ASP is Amnesiac Shellfish Poisoning
Which naturally occurring compound in cassava can release cyanide if improperly processed?
Linamarin.
A food sample was analyzed for aerobic plate count by diluting 100 and 1,000 times separately. the # of colonies on plate w/1:100 dilution was 240 with 1:1,000 was 35. What is the exact aerobic plate count of the food sample?
25,000 CFU/ml
Name 3 instrument and extensive factors that affect microorganisms growth in foods.
Temperature, water activity, pH
Name three obligate homofermenters.
Lactobacillus acidophilus (Common in probiotics and human gut) Lactobacillus delbrueckii subsp. bulgaricus (Essential yogurt starter) Lactobacillus delbrueckii subsp. lactis (Hard cheese production) Lactobacillus helveticus (Emmental and Gruyère cheese) Lactobacillus salivarius (Found in the digestive tract) Lactococcus lactis (Though not a Lactobacillus, it is an obligate homofermenter used in cheddar)
The International Association of Milk, Food and Environmental Sanitarians (IAMFES) have recently undergone a name change. What is the new name for this organization?
International Association for Food Protection (IAFP)
Which mycotoxin is associated with liver cancer? a. aflatoxin b. ochratoxin c. patulin
a. aflatoxin
Differentiate between food intoxication and infection and classify the following microorganisms if they cause intoxication or infection regarding foodborne illness: Clostridium botulinum, Campylobacter jejuni, Staphylococcus aureus, Aspergillus flavus, and salmonella species.
Intoxication is ingestion of toxins produced by certain pathogens in a food. Intoxication: Clostridium botulinum (botulinum toxin), Staphylococcus aureus (amongst the more common toxins secreted by S. aureus are hemolysin, leukotoxin, exfoliative toxin, enterotoxin, and toxic-shock syndrome toxin-1 (TSST-1).), Aspergillus flavus (aflatoxin) Food infection is when the food contains bacteria or other microbes which infect the body after it is eaten. Infection: Salmonella, Campylobacter jejuni
Which biogenic amine is most commonly implicated in scombroid fish poisoning?
Histamine.
What are the dominant spoilage microflora of fish?
Pseudomonas, Flavobacterium, and Moraxella.
Which of the following types of organism is not defined by temperature ? A. Psycrophiles B.Thermophiles C.Mesophiles D. Thermoduric
Thermoduric
What is the indicator organism used for thermal processing?
Geobacillus stearothermophilus (old name was Bacillus stearothermophilus)
Yeast has both sexual and asexual cycles.
True
What are the five steps used in the traditional isolation of Salmonella species?
1. Preenrichment 2. Selective Broth Isolation 3. Selective Plate Isolation 4. Biochemical Test 5. Serology.
What genus and species is used in the manufacture of blue cheese?
Penicillium roqueforti
What is the protein coat of a virus call?
Capsids
The legalization of what chemical compound as a sterilant for packaging materials allowed the development of aseptic processing?
Hydrogen Peroxide
In Scromboid poisoning, what serves as the precursor to histamine formation?
Amino acid Histadine
What animal is associated with the TSE disease Feline Spongiform Encephalopathy?
Cats
What is the source of tetrodotoxin?
Puffer fish
What is the main source of vibrio cholerae?
Shellfish
Which classical count method in microbiology counts both dead and viable bacterial cells?
Direct Microscopic Count
What is the D-value (decimal reduction time) defined as in food microbiology?
The time required at a specific temperature to kill 90% (or 1 log cycle) of a specific microorganism.
In the context of food safety and regulation, what does PRP stand for?
Pre-Requisite Programs
Food infection vs Food intoxication.
Infection has microorganisms living in the food, intoxication is when a biological end product (toxin) is in the food. Intoxication can be fatal
How many seconds should you wash your hands as stated by the CDC?
20 seconds in the US and 15 in Canada
What does the acronym CFU stand for?
Colony Forming Units
The sterilization value, also known as F sub zero describes what?
The integrated impact of time and temperature on the microbial population, expressed as time at the reference temperature, calculated by using the lethal rate times heating time
What are the four main stages in the life cycle of the Drosophila fruit fly?
Egg, Larva, Pupa, Adult Fly.
What is the time necessary at a given temperature to sterilize a suspension of bacteria and their spores (if they form spores)?
Thermal death time
What microorganism is used in the fermentation of both bread and beer?
Saccharomyces cerevisiae
What is the process of intermittent boiling done over 3 consecutive days?
Tyndallization
What is domoic acid?
A toxin found in limited quantities of anchovies and razor clams that causes illness in humans.
Under HACCP, pesticides come under which hazard category?
Chemical
Sweet acidophilus milk is made by growing active strains of Lactobacillus acidophilus in skim milk and then keeping the milk refrigerated before consumption.
False
Determine whether the following characteristics are of eukaryotic or prokaryotic cells: Does not have membrane bound organelles; true nucleus; Size 10-100 um; does not have membrane bound organelles; unicellular
Does not have membrane bound organelles (Pro) True nucleus (Eu) Size 10-100 um (Eu) Does not have membrane bound organelles (Pro) Unicellular (Pro)
When counting bacterial colonies, the acronym TNTC stands for what?
Too numerous to count
Claviceps purpurea causes what type of food poisoning?
ergot
What organism is included in the fermented sausage starter culture?
Pediococcus cerevisiae
What are the 5 main types of botulism?
Foodborne, infant, wound, Adult intestinal toxemia, Iatrogenic botulism
What is the minimum pH of growth for most Gram-negative aerobic bacteria?
pH 5.3.
Name 5 spices that have antimicrobial activity.
Garlic, cinnamon, cloves, onion, horseradish, and mustard
What is the mortality rate of Clostridium botulinum if ingested?
5-10%
Why was Schwan’s ice cream recalled from the marketplace in October of 1994?
Presence of Salmonella Enteritidis
what process is modeled by the Monod equation in foods?
Microbial growth
What type of toxin is aflatoxin?
Mycotoxin
What does EAEC stand for?
Enteroaggregative E. coli
Name three major causes of food deterioration
Growth and activity of microorganisms (yeasts, bacteria, molds); Natural food enzymes; Insects, parasites, and rodents; Temperature, both hot and cold; Air, oxygen; Light; Moisture and dryness
In thermal processing, the z-value represents the temperature change required to change the D-value by what factor?
A factor of 10 (or one log cycle).
What does aerogenic bacteria produce?
Gas
A product has a pH of 4.2 and water activity of 0.97. Discuss classification and safety concerns.
It is an acidified food (pH < 4.6). Primary concerns include acid-tolerant pathogens and spoilage organisms such as yeasts and molds. Appropriate strategies include pasteurization, preservatives, or refrigeration.
Explain food Spoilage.
Perishability of raw foods through microbial growth, enzymatic reactions, and chemical changes (mainly through factors of water, temp, and pH)
What is the causative organism for flaccid paralysis?
Botulinum
The D value of green peas is 0.2 minutes. What is the F value at 250 F?
12D so 2.4 minutes
What are the 3 most common types of human botulism?
Type A, B, E, F (rare)
Name four toxins responsible for PSP, paralytic shellfish poisoning.
Saxitoxins are a group of more than 50 structurally related neurotoxins, including saxitoxin (STX), neosaxitoxin (neoSTX), gonyautoxins (GTX), and decarbamoylsaxitoxin (dcSTX), produced by protists, algae, and cyanobacteria.
Name three obligate heterofermenters.
Lentilactobacillus brevis (formerly L. brevis) – Found in kefir and late-stage vegetable ferments. Limpasilactobacillus reuteri (formerly L. reuteri) – Probiotic found in breast milk. Lacticaseibacillus fermentum (formerly L. fermentum) Lactobacillus sanfranciscensis (The primary sourdough starter) Leuconostoc mesenteroides (The "pioneer" of sauerkraut fermentation) Oenococcus oeni (Used for malolactic fermentation in wine)
What microorganism was responsible for theIrish potato famine in the mid-19th century?
Phytophthora infestans
What is spice is very dangerous if it is injected intravenously?
nutmeg
State the seven principles of HACCP.
1. Conduct a hazard analysis. 2. Determine Critical Control Points (CCPs). 3. Establish critical limits. 4. Establish monitoring procedures. 5. Establish corrective actions. 6. Establish verification procedures. 7. Establish record-keeping and documentation.
What exemption is given to unpasteurized citrus juice under the FDA juice HACCP rule?
The 5 log reduction can be done cumulatively through treatments of the fruit and other steps in the process, rather that on the juice itself as required for all other juices
What are the four most important spoilage microorganisms associated with refrigerated meats?
Pseudomonas spp., Flavobacterium spp., Acinetobacter spp., and Moraxella spp.
Lack of proper handwashing is commonly associated with:
Shigella
What does FATTOM stand for?
Food acidity time temperature oxygen moisture
What kind of microorganism can survive MAP (Modified Atmosphere Packaging)?
Facultative anaerobes
What are Halophilic bacteria?
They love salt
Name 3 foods that are sources of Listeria.
Soft cheese made from unpasteurized milk, hot dogs, ready to eat deli meats, refrigerate spates or meat spreads, unpasteurized milk, refrigerated smoked seafood, raw sprouts
What is the food-borne illness associated with “red tide”?
Paralytic shellfish poisoning
What is a food intoxication?
An intoxication results when a person eats food containing toxins that cause illness
Food service personnel are becoming concerned about an intoxication that can result in diarrhea or vomiting; it is found in foods considered to be safe such as dry food mixes, spices, rice, etc. Contamination occurs from the soil in most cases.
Bacillus cereus
In terms of food fermentation, what does the acronym NSLAB stand for and name four.
Non-Starter Lactic Acid Bacteria; Lactiplantibacillus plantarum, Lacticaseibacillus casei, L. curvatus, Pediococcus
Adverse reaction to a food or food component that occurs through unknown mechanisms even including psychosomatic illnesses is called: A.food anaphylaxis, B.food idiosyncrasy, or C.metabolic reaction?
B.food idiosyncrasy
Describe Clostridium Botulinum.
Grows in anaerobic conditions, grows in low acid foods, produces a deadly toxin.
Name the genus of bacteria added with the starter culture for Swiss cheese.
Propionibacterium freudenreichii subspecies shermanii
What is the most common source of foodborne illness in Japan?
Vibrio from seafood
Name three facultative heterofermenters.
Lactiplantibacillus plantarum (formerly L. plantarum) – Found in sauerkraut, pickles, and olives. Lacticaseibacillus casei (formerly L. casei) – Used in Yakult and aged cheeses. Lacticaseibacillus rhamnosus (formerly L. rhamnosus) – Common probiotic strain. Lactobacillus curvatus (Fermented meats/sausages) Lactobacillus sakei (Kimchi and fermented meats)
What are the 2 main methods of plate counting?
Spread and pour plating
Identify three types of fungi commonly consumed in foods.
Yeast, molds and mushrooms
What is an enzyme that catalyzes the reduction of hydrogen peroxide to oxygen and water?
Catalase
Define “defect action level”.
The level of contamination that calls for seizing a product.
Clostridium botulinum produces one of the most potent heat-stable neurotoxins that can kill a susceptible person in minute quantities .
False
Freeze drying will kill all pathogens.
False
What are some of the disadvantages of using the general method to calculate lethality?
The initial temperature and time/temperature profile used in production must remain consistent with those used at the time of the heat penetration tests, not recommended for process development, there is a need for thermocouple nad measurement accuracy (with accurate calibration)
To what minimum temperature should potentially hazardous foods be reheated?
165°F
What foodborne parasites is also commonly found in used cat litter?
Toxoplasma gondii
Name extrinsic factor in foods which affect microbial growth.
Environmental conditions where the food is stored
What is spoilage caused by Erwinia carotovora and Pseudomonas marginalis that break down pectins, giving a soft mushy consistency, bad odor at times in foods like carrots, onions, garlic, etc?
Bacterial soft rot
What is the z value of Clostridium botulinum?
10 C or 18 F
What is an incipient contaminant?
naturally present on the food product
What is the single most important cause of food recalls in the USA?
Undeclared allergens on the label
What does high total counts in dehydrated foods indicate?
Poor raw materials, improper processing techniques, and poor sanitation.
Give the traits necessary to completely define a microorganism as a fecal coliform.
Gram negative rod, facultative anaerobe, ferments lactose at 44.5 degrees Celsius
The consumption of rotten apples may lead to intoxication by the presence of: A.yeast, B.spoilage bacteria, C.aflatoxins,or D.patulin
D. patulin
Name a carcinogen allowed in foods and its limit.
Aflatoxin up to 20ppb
Differentiate between homofermentative and heterofermentative lactic acid bacteria in terms of their products, and name two examples of each.
Homofermentative Lactic Acid Bacteria: These species are "specialists" that focus on producing lactic acid quickly. They are essential when the goal is a rapid drop in pH to inhibit spoilage organisms. Eg. Lactobacillus acidophilus: (Dairy/Probiotics), Pediococcus acidilactici: (Fermented meats/Sausage), Lactococcus lactis: (The primary starter for Cheddar and most hard cheeses), Lactobacillus bulgaricus: (One of the two mandatory bacteria required to make Yogurt), Streptococcus thermophilus: (The second mandatory yogurt bacteria; also used in Mozzarella) Heterofermentative Lactic Acid BacteriaThese species are the "flavor and texture artists." Because they produce CO2, ethanol, and esters, they provide the characteristic "tang," carbonation, and "eyes" (holes) in various foods. Eg. Leuconostoc mesenteroides: (Sauerkraut/Kimchi/Kefir), Lactobacillus brevis: (Vegetable fermentation/Sourdough), Lactobacillus sanfranciscensis: (The specific bacterium that gives San Francisco Sourdough its famous flavor), Oenococcus oeni: (Crucial in winemaking for "Malolactic fermentation," which softens the acidity of the wine), Leuconostoc citreum: (Commonly found in fermented seafood and kimchi)
In quality control, what does the term cross contamination mean?
Mixing raw product with processed product
What is the minimal water activity for most molds?
0.75-0.80
For what pathogen(s) is/are there a zero tolerance in ready to eat processed foods?
Salmonella species and Listeria monocytogenes.
Sauerkraut fermentation can be broken down into 3 different phases, early, middle and late. What bacteria is responsible for fermentation in each stage and what is their major fermentation products?
Early: Leuconostoc mesenteroides (Produces CO2 and acetic acid, lowers pH) Intermediate: Lactobacillus plantarum (Homofermentative, produces high levels of lactic acid) Late: Lactobacillus brevis (Further acidifies, final flavor development)
Explain pasteur effect.
The rate of glycolysis under anaerobic conditions is higher than the rate under aerobic conditions. Aerobic: citric acid cycle follows glycolysis; anaerobic: fermentation occurs
What does BHI stand for?
Brain Heart Infusion
What foodborne parasite is found in cat litter?
Toxoplasma gondii
What food is most associated with the foodborne illness agent Cronobacter sakazakii?
Infant formula
What is the temperature and time range for commercial sterilization?
116-121 C (240-250 F) for 50-90 min
Name one genus of bacteria that can cause ileocecitus, a disease that mimicks appendicitis.
Yersinia, Camplyobacter, Salmonella
What is the term for a foodborne illness caused by ingesting a microorganism, which then grows in the host's body and causes disease?
Foodborne Infection
What genus of microorganisms are most often involved with spoilage of refrigerated fresh meat, poultry, fish, and eggs?
Pseudomonas
Which is not an agent of paralytic shellfish poisoning? A. Saxitoxin B. Parasaxotoxin C. Neosaxotoxin D. Gonyautoxins (GTX) E. Decarbamoylsaxitoxin
B. Parasaxitoxin
What does Saccharomyces literally mean?
Sugar fungus
What is the predominant component of the Gram (+) cell wall?
Peptidoglycan
Give the temperature and z value for the commonly used/standard F sub zero value that is based on the destruction of a population of C. botulinum.
Temperature: 250 F or 121 C, z value: 18 F or 10 C
Freezing temperatures stop bacterial growth, but may allow bacteria to survive.
True
Answer the following about Listeria monocytogenes: Why is it a concern in refrigerated foods? Name three food categories commonly associated with outbreaks. Describe one control strategy used in food processing environments.
Why it is a concern in refrigerated foods: Listeria is psychrotrophic, meaning it can grow at refrigeration temperatures. Food categories commonly associated with outbreaks (any three): Ready-to-eat deli meats, Soft cheeses (especially unpasteurized), Smoked seafood, Pre-cut fruits and vegetables One control strategy: Environmental monitoring programs in processing facilities, Use of post-lethality treatments (e.g., HPP), Strict sanitation and separation of raw and RTE areas
Pasteurization time and temperature is based on the destruction of which microorganism?
Coxiella burnetti
What structures do bacteria such as e. coli use for movement?
Flagella
What naturally occurring carcinogen, produced by the mold Aspergillus flavus, is a common contaminant of peanuts, corn, and tree nuts?
Aflatoxin
In a micro lab, you dilute 1 ml culture in 99 ml water, then 1 ml in 9 ml, and then pipette 0.1 ml on a spread plate. What is the final dilution?
10^-4 or 1/10,000th
Explain the difference between D-value, z-value, and Fâ‚€-value, and state what each represents.
D-value: time at a given temperature to reduce microbial population by 90%. z-value: temperature change needed to change D-value by one log cycle. F₀-value: equivalent minutes at 121°C providing the same lethality.
Which of the following is not a differential media: A. Eosine Methylene Blue agar B. Mannitol salt agar C. McConkey agar D. Yeast and mold agar
D. Yeast and mold agar
List four method used to find the total number of microorganisms in foods.
Pour plate, surface spread plate, surface drop, agar droplet, and microdilution
Name two anti-microbial factors found in raw milk.
Lactoperoxidase, lactoferrin, lysozyme
What microbe is used to make vinegar?
Acetobacteria
Explain TDT (Thermal Death Time) Studies.
Done to determine an organism's heat resistance (D-value) in a specific product to develop a process for that product
Which foodborne pathogen also causes necrotic enteritis in poultry and gas gangrene in humans?
Clostridium perfringens
Name 2 conditions under which yeasts and molds will out compete most bacteria
low Aw (0.6-0.7); 2 > pH > 9
What is the medical term or name given to the condition where bacteria are actively multiplying in the bloodstream?
Septicemia
What pathogen is most commonly associated with undercooked poultry?
Salmonella
Scromboidosis is one of the most common seafood poisonings. The ingestion of what compound is responsible for the illness?
Histamine
When viewed under a microscope after gram staining, gram negative bacteria appear what color?
Pink to red
List the 'Big 8' allergens in the US.
Shellfish, Fish, Milk, Eggs, Soy, Wheat, Peanuts, and Tree Nuts
What causes ergotism (st. anthony's fire)?
Caused by eating toxic alkaloids produced by the fungus Claviceps purpurea. On wheat, barley, rye, oats, and wild grasses. Max. level of ergot allowed 0.1% dry weight in barley, oats, 0.3% dry weight in wheat and rye
What is the difference between gram positive and gram negative bacteria.
Gram-positive bacteria have a thick peptidoglycan cell wall and no outer membrane, staining purple in a Gram stain. Gram-negative bacteria have a thin peptidoglycan layer, an outer membrane with lipopolysaccharides, and stain pink.
Cyanogenic glycosides are compounds that when treated with an acid or appropriate hydrolytic enzyme yield what compound?
cyanohydron
which media may be used to selectively enumerate coliforms?
Violet Red Bile Agar (VRBA)
Name three types of shellfish poisoning.
Paralytic, neurotoxic, amnesiac, diarrhetic
What are the shapes of following divisions of bacteria? cocci, bacilli, spirilla, vibrios, spirochaetes
Spherical (cocci), rod (bacilli), spiral (spirilla), comma (vibrios) and corkscrew (spirochaetes)
In order list the 7 steps of HACCAP.
1. Conduct a hazard analysis, 2. Identify CCP, 3. Set critical limits, 4. Establish monitory procedures, 5. Establish corrective actions, 6. Verification, 7. Establish record keeping
What genera of gram negative, facultative anaerobe are catalase positive, oxidase negative, ubiquitous, lactose non-fermenting, H2S positive and cause foodborne illness?
Salmonella
What color do the cells of gram positive and gram negative bacteria appear after staining?
Gram-positive bacteria appear purple or blue, while Gram-negative bacteria appear pink or red.
Who is most responsible for disproving Spallanzani's theory of spontaneous generation?
Louis Pasteur
What are the microbial inhibitors in egg whites and how do they work?
The albumen is beneath the shell membranes and is important in providing three antimicrobial defenses to the egg. The first defense is the viscosity of the albumen components, which provide conditions in which bacteria cannot move easily. The second defense is the alkaline pH of the albumen that initially ranges from 7.6 to 7.8 but quickly increases over a period of a few days due to the loss of carbon dioxide during storage, resulting in a pH of 9.1–9.6. This is a pH range that is not conducive to the growth of most microorganisms. The third defense is the presence of a number of proteins and glycoproteins that possess antimicrobial activity: lysozyme (breaks cell walls), ovotransferrin (binds iron), and avidin (binds biotin).
What is the measurement of the degree to which a chemical is poisonous to an organism?
Toxicity
Explain D-value, Z-value, and F-value, and how they are used in thermal process validation.
D-value is the time at a given temperature to reduce a microbial population by 90%. Z-value is the temperature change needed to change the D-value by one log cycle. F-value represents the equivalent time at a reference temperature to achieve a desired level of microbial lethality. Together, they are used to design and validate safe thermal processing conditions.
Aflatoxin can be detected by placing material under: A.fluorescent light, B.a light bulb, C.UV light, or D. infared light?
C. UV light
Which thermoduric, acidophilic, spore forming bacterial species is an emerging spoilage issue for juice and beverage processors?
Alicyclobacillus
What is the minimum internal cooking temperature for poultry recommended by USDA?
165°F (74°C).
Which genus of bacteria is commonly used as an indicator of fecal contamination in water and foods?
Escherichia (specifically E. coli).
What does ServSafe say is the distance food should be off the ground for dry food?
6 in
What do the following media stand for, what organisms do they select for and how do the colonies appear on the media? (ask any 5) PCA, PDA, MacConkey, McBride, MRS, XLD, VRBA, VRBGA, Baird-Parker, Cetrimide, Blood, SS, EMB, MYP, BHI, Oxford, BS, TSC, HE, PIA
PCA: Plate Count Agar, total viable bacteria, creamy/white colonies PDA: Potato Dextrose Agar, yeasts (smooth colonies) and molds (filamentous colonies) MacConkey Agar: Gram negative bacteria, enterobacteriaceae, lactose fermenters (pink/red) vs non-fermenters (colorless) McBride agar: Listeria monocytogenes, small, translucent, blue-gray colonies (when viewed with Henry illumination) MRS: de Man, Rogosa and Sharpe agar, LAB, white/creamy XLD: Xylose Lysine Deoxycholate agar, salmonella (red with black center) and shigella (red w/o black centers) VRBA: Violet Red Bile Agar, coliforms, red/purple colonies with red-purple halos VRBGA: Violet Red Bile Glucose Agar, Enterobacteriaceae, red or purple Baird-Parker: Staphylococcus aureus, black shiny colonies with clear zones/halo Cetrimide: Pseudomonas aeruginosa, large flat colonies producing greenish blue pigment Blood agar: hemolytic bacteria, colonies with different hemolysis: alpha: greenish, beta: clear, gamma: none SS: Salmonella-Shigella agar, Salmonella (colorless with black centers), Shigella (colorless) EMB: Eosin Methylene Blue agar, Gram negative enteric bacteria, lactose fermenters; E. coli (metallic green sheen), other lactose fermenters (purple), non-fermenters (colorless) MYP: Mannitol egg Yolk Polymyxin; Bacillus cereus, large, pink to red colonies surrounded by a distinct zone of precipitation (cloudiness) BHI: Brain Heart Infusion; Listeria monocytogenes, small, smooth, creamy white or translucent colonies Oxford: Listeria monocytogenes, small, black colonies surrounded by a black halo BS: Bismuth-Sulfite; Salmonella, black or metallic green colonies, often with a "rabbit eye" appearance (a black center with a clear edge) and a dark "halo" in the surrounding agar TSC: Tryptose Sulfite Cycloserine, Clostridium perfringens, black colonies HE: Hektoen Enteric Agar, Differentiates Salmonella and Shigella from other Enterobacteriaceae, Salmonella: Blue-green colonies with black centers (H2S production).Shigella: Green to blue-green colonies without black centers.Coliforms (like E. coli): Large, yellow to salmon-orange colonies. PIA: Pseudomonas Isolation Agar, Pseudomonas aeruginosa, typically producing blue to blue-green, convex, and often smooth or mucoid colonies
This term describes the dose required to kill half the members of a tested population after a specified test duration?
LD50
What is an anaerobic bacteria?
A bacteria that does not require oxygen for growth
What concept motivates the use of multiple preservative factors to prevent growth of pathogens in processed foods?
The hurdle concept.
The Christie—Atkins—Munch-Peterson (CAMP) test is used to identify what foodborne pathogen?
Listeria monocytogenes
the classification of a microorganism based on its response to an antibody assay is called what?
Serotyping
Of the following pathogens, which one was recognized even 30 years ago: campylobacter jejuni, Listeria monocytogenes, Bacillus cereus, Cyclospora cayetanensis?
Bacillus cereus
What is the minimum pH of growth for most Gram negative aerobic bacteria?
5.3
A microbial population has been decreased by what percentage when it undergoes a one-log reduction?
0.9
What is the white colony growth of molds called?
Mycelium
If the total plate count is 500 CFU/ml, with the generation time of 30 min., what will the total plate count be after 3 hours?
32,000 CFU/ml
Is the osmotic pressure higher or lower inside a growing cell as compared to the external environment?
Higher, Cell elongation during growth is followed by influx of water into the vacuole
What element in commerical apple juice can be fatal after chronic exposure?
Arsenic
What two lactic acid thermophilic bacteria are inoculated into pasteurized milk in the fermentation process that yields yogurt?
Streptococcus thermophilus and Lactobacillus delbrueckii spp. bulgaricus
Which two microorganisms, genus and species, are used for biofuel production?
Aspergillus niger, Saccharomyces cerevisiae
What is the lethal rate used to calculate?
converts the thermal death time at temperature T to equivalent thermal death time at a reference temperature in order to destroy the same population of spores
Describe the Big Six pathogenic E. coli, their primary food associations, and why they are regulated similarly to O157:H7.
O26, O45, O103, O111, O121, O145; associated mainly with beef and produce. They produce Shiga toxins and cause severe illness, warranting equivalent regulatory control.
What two organisms are involved in vinegar production and in what order?
S. cerevisiae and acetobacter
What is the measurement of oxygen utilized in the stabilization of organic matter by microorganisms over a 5 day period at 20 C called?
Biological oxygen demand
What is the most heat resistant pathogen found in milk?
Coxiella burnetii
What component of bacterial cell causes difference in color in gram staining?
Cell wall/ Peptidoglycan
What term describes the dose at which 50% of a test population experiences lethality?
LDâ‚…â‚€.
What is the term used to describe the allowable tolerances of natural or unavoidable foreign materials in foods which do not constitute a health hazard to the public?
Defect action level
What type of foodborne disease is caused by Staphylococcus aureus?
Intoxication
Name 3 fungal genuses that produce mycotoxins.
Penicillium, Fusarium, Aspergillus
H5N1 virus is also commonly known as what?
Influenza A virus, Avian Influenza virus, or Bird Flu virus
What does PDA stand for?
Potato Dextrose Agar
What type of microorganism is destroyed by pasteurization but can survive sterilization-resistant spores?
Vegetative cells.
Lysine is produced by which genus of bacteria?
Brevibacterium
Define the concept of thermal death time.
The time to kill a given number of organisms at a given temperature under specific conditions
To meet health regulation and prevent foodborne illness, prepared food must be held at what temperature if it is to be served warm?
At or above 60°C (140°F)
What does ETEC stand for?
Enterotoxigenic E coli
What kind of poisoning is caused by dinoflagellates?
Gonyaulax and Alexandrium (dinoflagellates) cause Paralytic Shellfish Poisoning (PSP), other dinoflagellates cause Diarrhetic (DSP) and Neurotoxic (NSP) versions
What is the difference between the terms bacteriostatic and bacteriocidal?
Bacteriostatic inhibits bacteria and bacteriocidal kills bacteria
What is the term for any bacterial or viral material used for inoculation against a specific disease?
Vaccine
Name 4 classes of potential hazards of concern during food processing as defined by FSMA.
Microbial, Chemical, Physical, Radiological
What three food commodity groups have the federal government proposed mandatory HACCP plan implementation?
Seafoods, meats, poultry
Which bacterial species is most commonly associated with raw poultry contamination?
Campylobacter jejuni
Define fecal coliforms and indicate the reason that they are often evaluated in foods.
Facultative anaerobes (organisms which can survive in the absence of oxygen), gram-negative, non-spore forming, rod-shaped bacteria that ferment lactose (a type of sugar), producing gas and acid within 48 hours when cultured at 44.5 C. Their lack of ability to form spores makes them more susceptible to destruction by environmental conditions.they are used as indicators of fecal contamination
Botulinum toxin type H is the deadliest substance in the world, but type A is used for what commercial application?
Botox
What is the bacteria of greatest concern in home canned foods?
Botulism
The organism that causes 'flat sours' in canned tomatoes is
Geobacillus stearothermophilus (old name was Bacillus stearothermophilus)
What are the two foodborne bacterial intoxications?
Staphylococcal intoxication: an enterotoxin produced by S. aureus, botulism: a neurotoxin produced by clostridium botulinum
In microbiology, what does the index IMViC stand for?
Indole, Methyl Red, Voges-Proskauer test, and Citrate test
What does EPEC stand for?
Enteropathogenic Escherichia coli
What are the typical organisms used in the production of cottage cheese?
lactococcus lactis subsp lactis, lactococcus lactis subsp. Cremoris; homofermentative fast acid producing
What mycotoxin, also a potent carcinogen, is produced by a mold that can grow on moist peanuts, pecans, corn and other foodstuffs?
Aflatoxin
What is the difference in a wild and controlled fermentation?
Controlled adds microorganism and wild uses those already present
Name five probiotic microorganisms.
Lactobacillus acidophilus, Lactobacillus casei, Lactobacillus plantarum, Lactobacillus rhamnosus, Bifidobacterium bifidum, Bifidobacterium longum, Bifidobacterium animalis, Streptococcus thermophilus, Enterococcus faecium, Kefir (mixture of Lactobacillus and Bifidobacterium), Saccharomyces boulardii (a yeast), and Limosilactobacillus reuteri.
What type of microorganism is Clostridium botulinum?
Obligate anaerobic, spore-forming bacterium.
What is the name of the toxin family responsible for the majority of seafood illnesses?
Phycotoxins
What does the abbreviation related to shellfish toxin NSP stand for?
NSP is Neurotoxin Shellfish Poisoning
What is the infectious dose of norovirus (approx.)?
As few as 10–100 viral particles
What is the minimum temperature for holding food on a steam table.
140 F or 60 C
Homo sapiens is a gram-positive short rod.
False
Explain the difference between indicator organisms and index organisms, with examples.
Indicator organisms signal general sanitary quality (e.g., total coliforms), while index organisms indicate the possible presence of specific pathogens (e.g., E. coli as an index for enteric pathogens).
In what types of foods are thermophilic sporeformers of primary concern?
Aseptically processed low acid foods.
Why do bacteriologists incubate pathogens at 37C?
It is the human body temperature
What is the log reduction required for milk and what pathogen are they controlling for? What about egg shells?
Milk - 6D process targeting Coxiella burnetii (the most heat-resistant non-spore-forming pathogen in milk). Eggs - 5D process and they are controlling for Salmonella seftenberg
Which pathogen is associated with unpasteurized juices and low infectious dose?
E. coli O157:H7.
Besides extending shelf life and preventing microbial growth, what is another benefit of reducing the water activity of a food?
A lower water content means a lower product volume, making the product easier and cheaper to transport
What is the minimum water activity for most yeast?
0.87
PSP, DSP, NSP, ASP stands for what regarding shellfish toxins?
PSP: Paralytic Shellfish Poisoning; DSP: Diarrhetic Shellfish Poisoning; NSP: Neurotoxic Shellfish Poisoning; ASP: Amnesic Shellfish Poisoning
What are some advantages of aseptic processing?
Convenience (many foods can undergo aseptic processing), safety (protect against spoilage and foodborne illness), flavor and freshness (captures the natural flavors and has a fresh clean taste), natural (no need for preservatives)
What are the three major genera of mycotoxin producing fungi?
Aspergillus, penicillium, fusarium
Rank the following in order of their tolerance to low water activity (highest resistance to least): yeasts, bacteria, molds
Molds, yeasts, bacteria
What 3 microorganisms are involved in the production of soy sauce?
Aspergillus seed starter, soy yeast, lactic acid bacteria
Most common pathogen found in outbreaks of cheese?
L. monocytogenes.
What is the area under a lethal rate curve defined as?
Lethality
Define endotoxin.
Endotoxin is a complex lipopolysaccharide (LPS), a toxic substance found in the outer membrane of most gram-negative bacteria
Name the five quality grades of pork carcass.
US no. 1, US no. 2, US no. 3, US no. 4, Utility
Which two food pathogens are considered as new and emerging food pathogens?
Campylobacter jejuni, Yersinia enterocolitica
In dairy cows, what happens to alfatoxin B1 ingested with feed?
A small percentage is metabolized and excreted in milk as Aflatoxin M1.
Which microorganism is used in tempeh fermentation?
Rhizopus oligosporus
What is a facultative anaerobe?
A microbe that can grow with or without oxygen.
Outbreaks of Salmonellosis from consumption of raw almonds in 2000 and 2004 were caused by rare phage types of Salmonella Enteritidis. What were these two rare phage types?
PT 30 in 2000 and PT 9c in 2004
Thermophiles
Bacteria that love high heat
Salmonella was first isolated from salmon fish in an outbreak in Washington State in 1889.
False
The Howard Mold Count was developed as a method of monitoring the quality of what type of food products?
Tomato products
What fungus is used in the production of sake, soy sauce and rice vinegar?
Koji mold/ Aspergillus Oryzae
When is a microorganism considered dead?
When it is irreversibly unable to divide
List three main types of foodborne hazards and give one example of each.
Biological: Salmonella Chemical: Pesticide residues Physical: Glass shards
Which pathogen is most commonly associated with refrigerated ready-to-eat meats?
Listeria monocytogenes.
Plasmid is extrachromosomal DNA.
True
From what source is C. bot first isolated?
Smoked ham
which primary microorganisms are responsible for contagious mastitis in cows?
Staphylococcus aureus and streptococcus agalactiae
What type of HACCP hazard would jewelry be considered?
Physical
If fermentable carbs are present when pickling food, what percent acid must be present to prevent growth of lactic acid bacilli and yeasts?
0.036
Major tests for allergies.
RAST, Basophil Histamine Release, Skin test, Oral challenge, Immunoblotting
Genera for Downy Mildew disease.
Sclerospora bremia
Intrinsic factor in foods which affect microbial growth.
pH, redox potential, nutrient content, water activity
What value measures the heat resistance of a microorganism?
D-value
What are SOP and SSOP?
Standard operating procedure, sanitation standard operating procedure.
Which microorganism is commonly linked to undercooked ground beef outbreaks?
Escherichia coli O157:H7.
Which group of pathogenic bacteria is most often responsible for traveler's diarrhea?
Enterotoxigenic Escherichia coli
Describe tyndallization and how it works.
Intermittent heating (usually at 100 C for 30 minutes) over 3 consecutive days. The first heating kills vegetative cells. During the incubation period between heatings, the surviving spores germinate into vegetative cells, which are then killed by the subsequent heating.
Which microorganism is used as an indicator of fecal contamination in water and foods?
Escherichia coli
What aspect of Staphylococcus aureaus does selective media 110, exploit?
Salt tolerance
What are ascospores?
Sexual spores of molds, formed by the union of 2 cells within the mycelia; spores are held within an ascus (sac-like structure)
Name the microorganism associated w/ Patulin.
Penicillium expansum
Food radiation can destroy all the following in food except:
Prions
What is the function of heterofermentative lactic acid bacteria in fermented foods?
Production of flavor compounds (acetaldehyde and diacetyl) (homofermenters increase acidity)
What highly toxic lectin compound is contained in castor beans?
Ricin
Name three bacteria commonly associated with food poisoning. (Does not need to be full scientific name.)
Salmonella, Norovirus, Campylobacter, E. coli, Listeria, Clostridium perfringens
What is the ‘best if used by/best before’ date used for?
A guide to the quality or flavor profile of a food product
You are starting to feel nauseous and remember possibly eating some undercooked chicken a few days ago. What type of bacteria is most likely making you sick?
Campylobacter jejuni (2-5 incubation days)
Name 5 organelles of cells.
Mitochondria, nucleus, vacuole, ribosome, Golgi apparatus, cell wall, cell membrane/plasma membrane, endoplasmic reticulum (SER, RER), lysosomes, peroxisomes, cytoskeleton
Which of the following foodborne illnesses is not caused by preformed toxins ingested from contaminated food? A. Infant botulism B. Staphylococcal food poisoning C. Bacillus cereus emetic syndrome D. Foodborne botulism
A. Infant botulism
Which bacterial stress response system regulates acid tolerance in Listeria monocytogenes?
Glutamate decarboxylase (GAD) system.
EAEC, EHEC, EIEC, EPEC and ETEC represent five serological grouping of five virulent strains of what bacterium?
Escherichia coli
What microorganism does Bismuth-Sulfite agar select for?
Salmonella
What is the difference between food spoilage and food poisoning?
Spoilage = inedible food but not unsafe (judgmental to what is not acceptable); poisoning = causes illness through infections(detrimental effect to system)
Name four genera of bacteria known as coliforms.
Citrobacter, Enterobacter, Escherichia, and Klebsiella
What does CFSAN stand for?
Center for Food Safety and Applied Nutrition
Which pathogen is most associated with refrigerated, vacuum-packaged seafood?
Clostridium botulinum type E.
What are two types of enzymatic spoilage caused by Pseudomonas fluorescens refrigerated foods?
Proteolysis and lipolysis
Which pathogen produces heat-stable enterotoxins that cause vomiting within hours of ingestion?
Staphylococcus aureus
What are the four C's of food safety?
1. Clean hands, equipment, utensils and work area with soap and hot water. 2. Cook food until the temperature reaches at least 140 F. 3. Chill foods immediately after purchasing and after serving. Maintain at a temperature of less than 40 F. 4. Avoid cross-contamination from bacteria by keeping raw foods away from cooked and ready-to-eat foods.
What do the following acronyms stand for wrt food safety? DAEC, ETEC, EAEC, EHEC, EPEC, EIEC
Diffuse-adhering E. coli(DAEC), enteropathogenic (EPEC), enterotoxigenic (ETEC), Enteroinvasive (EIEC), Enterohemorrhagic (EHEC), Enteroaggregative (EAEC)
The presence of beta-giucuronidase signifies the presence of what microorganism?
Escherichia coli
Which compound found in chocolate is toxic to dogs?
Theobromine
What value is the time required to have 1 log reduction or 90% in microorganisms or spores in a sample at a specific temperature?
D-value
What does PIA stand for in food microbiology?
Pseudomonas Isolation Agar
St. Anthony's Fire outbreaks are now very rare. It is caused by a toxin on rye or wheat produced by what ?
Claviceps purpurea
A ready-to-eat refrigerated hummus product: Identify three major food safety hazards. Propose two processing or formulation controls. Suggest one packaging strategy to extend shelf life.
Three major food safety hazards: Listeria monocytogenes, Salmonella, Spoilage microorganisms (yeasts, molds) Two processing or formulation controls: Acidification (low pH), Use of preservatives (e.g., potassium sorbate), High-pressure processing, Strict sanitation and environmental monitoring One packaging strategy to extend shelf life: Modified atmosphere packaging (MAP), High-barrier packaging, Refrigerated distribution with cold-chain control
Name one spore-forming, thermophilic bacterium that can spoil canned foods.
Clostridium thermosaccharolyticum.
What toxic substance is found in Gari, and what is the name of the tuber that this fermented product comes from?
Cyanogens, Cassava
Define the D-value and the Z-value.
Z-value – temperature required to decrease the time necessary to obtain a 1 log reduction in cell number to 1/10th of the original value D-value – the time in minutes at a specific temperature to reduce the number of microogranisms by 1 log cycle, AKA kill 90% of micorbes.
Name in microbial reduction process for spices and seasonings.
Irradiation
What microorganism has been linked to the disease Guillain-Barré syndrome?
Campylobacter jejuni
A resting period of certain protozoa is called what?
Cyst.
Name 3 strains of mold that produce mycotoxin.
Aspergillus flavus, Aspergillus parasiticus, Claviceps purpurea, Penicillium citrinin, Penicillium expansum, Fusarium spp.
The magnification of a microscope with an eye piece of 10X and an objective of 97 X is what?
970X
What are halophiles?
Microorganisms that can survive high concentrations of salt
To prevent the reoccurence of Staphylococcus food poisonings through spray-dried nonfat milk, the USDA incorporated DMCC levels as a quality factor in the US Standards for Grades of Nonfat Dry Milk. What does DMCC stand for?
Direct Microscopic Clump Count
What end product does the Voges-Proskauer test detect?
Acetoin
The cause of an outbreak of a foodborne illness was traced to Brie cheese. What bacterium is primarily responsible?
Listeria monocytogenes
Which microorganism is the leading cause of bacterial foodborne illness in the United States?
Salmonella spp.
Name 2 ways yeast divide.
Budding (a special kind of mitosis) and Meiosis
What end product(s) are produced in heterofermentation?
Heterofermentation is when bacteria produce lactic acid, CO2, ethanol, and sometimes acetic acid
What is the spherical organism which causes souring of milk?
Streptococcus lactis.
Which is not a property of the muscle protein collagen? a. white color b. elastic c. heat degradable
b. elastic
What are hemolytic bacteria?
Bacteria that can lyse blood cells
In the 2022 Food Code by FDA this term means a point or procedure in a specific food system where loss of control may result in an unacceptable health risk.
Critical Control Point.
The following steps should be followed for cleaning food contact equipment and utensils: 1) prerinse 2) soap and scrub (washing) 3) rinse 4) sanitize 5) air drying
True
Integration of lethality when the reference temperature is 121.1 C (250 F) and z = 10 C (18 F) will determine which value?
F sub zero
What microorganism is used to make koji in sake brewing?
Aspergillus oryzae
Which genera contains bacteria that can fluoresce and contains members that commonly cause spoilage of fresh cut vegetables and meats?
Pseudomonas flurescens
In terms of food fermentation, what does the acronym NSLAB stand?
Non Starter Lactic Acid Bacteria
What are the 2 different syndromes associated with Bacillus cereus?
diarrheal syndrome and emetic syndrome
What three terms, respectively, are used to describe the ability of microorganisms to grow at cold, ambient and warm temperatures?
Psychophilic (or psychrotrophic), mesophilic, thermophilic
Define mycosis.
disease resulting from the invasion of living cells by a fungi
What is the microbiological technique used to measure the amount of microbial colonies on a surface?
RODAC plating
Xenobiotic definition?
Substances that are foreign to the body or to an ecological system
What cheese is associated w/ the following major microorganisms: lactococcus, propionibacterium shermanii, penicillium roqueforti, Lactic streptococci
Lactococcus= cheddar (or mozzarella); propionibacterium shermanii= Swiss; penicillium roqueforti= Blue; Lactic streptococci= Edam, Gouda
Name 2 food born pathogens that can grow at refrigerator temperatures.
Yersinia enterocolitican, aeromonas hydrophilia, listeria monocytogenes
Name the four key conditions or intrinsic factors often represented by the acronym FATTOM that influence the growth of most foodborne bacteria.
Food (nutrients); Acidity (pH); Time; Temperature; Oxygen (or lack thereof); Moisture or Water Activity).
Which mycotoxin is most commonly associated with Aspergillus flavus contamination in peanuts and corn?
Aflatoxin B₁
The enumeration technique for microorganisms which uses 3 sets of tubes with, 3, 5, or 10 tubes per set is called what?
Most probable number
What is a psychrotroph?
A microorganism that grows at 7 degrees Celsius or below (in the refrigerator).
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