Exam Questions And Correct Answers
Four phases of bacterial presence in food
1. Lag Phase, 2. Log Phase, 3. Stationary Phase, 4. Death Phase
Log phase
Most essential phase of bacterial presence in food due to the fastest increase in
populations
Lag phase
Time/temp play an important role in keeping bacteria in this phase (where numbers are
less dangerous and growth is slowed)
Norwalk virus
Rarely a pathogen associated with shellfish
Hepatitis A virus (HAV) and Vibrio spp (a bacteria)
2 common pathogens associated with shellfish
,6 - 7 weeks
Incubation period for Hep A can be up to ___ to ___ weeks
Document retention rationale for shellfish
6 - 7 week Hep A incubation period is part of this rationale for retaining shellstock tags
for 90 days beyond the date of harvest. Batches should not be mixed. Time allows for
the presentation of any Hep Aand gives infor on tracking the location and source of the
outbreak.
Pathogens found in soil
Bacillus cereus, Clostridium botulinum, Clostridium perfringens, Listeria monocytogenes.
To a lesser extent: Salmonella spp, Yersinia enterocolitica
Cooked Rice
Food typically associated with an outbreak of Bacillus Cereus
Staphylococcus aureus
50 - 70% of people are carriers of this pathogen
, Upper respiratory tract; also frequently found in pimples, burns, sores, other skin
lesions
Location in the body where Staph is typically found
Cause of Staph foodborne illness
Toxins formed by bacteria and not the live bacteria that cause the illness. Possible to
have the bacteria without toxins. Staph bacteria in the upper respiratory tract may not
cause illness, but bacterial Staph toxins in the gastro intestinal tract in the same person
may cause illness.
Foods typically associated with Listeriosis outbreak
Unpasteurized milk and associated milk products (raw milk cheese); prepared and
chilled RTE foods like some soft cheeses, deli meats, hot dogs, pate; raw veggies (makes
sense given Listeria can be present in soil); pouttry, meat and seafood
Salmonella and E. coli 0157:H7
Pathogens associated with unpasteurized juices
Aerobic bacteria
require oxygen for survival and for multiplication sufficient to cause disease