Microbiology

What are the three spore-forming foodborne pathogens?

Bacillus cereus, clostridium perfringens, clostridium botulinum

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 five yeast fermented food products.

Beer, wine, bread, distilled spirits, kefir, kombucha, root beer

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)

Name three hazard classes identified by HACCP.

Biological, Chemical, Physical

List three main types of foodborne hazards and give one example of each.

Biological: Salmonella Chemical: Pesticide residues Physical: Glass shards

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)

Name 2 ways yeast divide.

Budding (a special kind of mitosis) and Meiosis

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

Name the 10 states in the FoodNet active Surveillance Program.

Californa, Colorado, Connecticut, Georgia, Maryland, Minnesota, New Mexico, New York, Oregon, and Tennessee

Name four genera of bacteria known as coliforms.

Citrobacter, Enterobacter, Escherichia, and Klebsiella

Name the 4 steps of the Fight BAC program.

Clean, Separate, Cook, Chill

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

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 four chemicals involved when conducting a Gram stain?

Crystal violet, iodine, alcohol-acetone, safranin

Formula to calculate D-value.

D = t/(log N0 - log Nf); D = D-value, t = time, N0 = initial population, Nf = final population

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.

Explain the difference between D-value, z-value, and F₀-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 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

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)