Questions and CORRECT Answers
Anisakis - CORRECT ANSWER - roundworm common in sushi; salmon, cod, squid,
cuttlefish, octopus; cooking/freezing inactivates; onset 1-2 weeks
Cyclospora cayetanensis - CORRECT ANSWER - parasite; assoc. with fresh produce; rare
in US, common in areas around the tropics; explosive watery diarrhea, loss of appetite, bloating;
onset 1 week
Cryptosporidium parvus - CORRECT ANSWER - parasite; large amounts of severe,
watery diarrhea; onset 1 week
Entamoeba hystolytica - CORRECT ANSWER - Amebiasis; not common in US; poor
hygienic practices, contaminated water on fruits and vegetables; range from no symptoms to
dysentery; may last for years; onset 2-4 weeks
Giardia lamblia - CORRECT ANSWER - parasite; contaminated food or water; not killed
by common chlorine mixtures; onset 1-2 weeks
Nematodes - CORRECT ANSWER - roundworms; undercooked meats, esp. wild game
such as bear and boar, domestic pigs; travel from bowel throughout body; die in organs, causing
inflammation; onset 2-28 days
Tapeworms - CORRECT ANSWER - Taenia solium (pork), Taenia saginata (beef);
undercooked pork or beef; hunger pains, severe wait loss, insomnia; onset 2 months to develop
to full size
thermophilic - CORRECT ANSWER - high temperatures, 113 to 252F
psychophilic - CORRECT ANSWER - capable of growth and reprod. at low temps 5-50F
, mesaphilic - CORRECT ANSWER - moderate temps 68-113F
psychotrophic - CORRECT ANSWER - grow well at refrigeration temps 30-50F
thermoduric - CORRECT ANSWER - heat resistant and can survive cooking temps as
well as pasteurization
lag phase - CORRECT ANSWER - initial growth, cell # remains constant prior to rapid
growth, longest of 4 phases; cells replicating various proteins and DNA to prep to grow (may be
sev days to hours depend on bact)
log phase - CORRECT ANSWER - steepest slope, double pop every 20-30 min.,
"logarithmic" phase
stationary phase - CORRECT ANSWER - plateau of growth curve, new cells at same rate
cells die, resources being used, state of equilibrium
death phase - CORRECT ANSWER - final phase, dead outnumber new cells, limited
resources, waste production, other changes to environment; colony starts over at first phase
pH - CORRECT ANSWER - 4.6-7.5
water activity - CORRECT ANSWER - the measure of the energy status of the water in a
system; microbial cells compete with solute molecules for free water molecules (molds better
competitors than bac, excluding staph aureus), 0.85; varies little with temp
spore formers - CORRECT ANSWER - B. cereus, C. bot, C. perfringens
toxin formers in food - CORRECT ANSWER - B cereus, C bot, Staph aureus