Food Poisoning

Question 1

S. aureus

Answer 1

G+ cocci; grape-like clusters
catalase + (diff from strep)
coag + (diff from other staph)
beta hemolytic

Question 2

S. aureus virulence

Answer 2

enterotoxin (serotypes A-D)
heat stable
resistant to acidity and gast enzymes
stim peristalsis
stim vomiting
can stim TSS and mediate cytokine storm

Question 3

S. aureus food poisoning

Answer 3

1-6hrs after eating
N/V/D/sweating/headache/cramps
watery and nonbloody diarrhea
antibios not indicated

Question 4

Bacillus cereus

Answer 4

G+ rod
spore-forming
resist to dry heat and chemical changes
grains including rice
esp reheated rice (spores germinate when warmed)

Question 5

B. cereus food poisoning

Answer 5

emetic --> 4hrs
heat stable enterotoxin
contaminated rice
self limiting
diarrheal --> 24hrs
resembes clostridial gastroenteritis
heat labile toxin --> inc cAMP
contam meat, veggies, gravies
self limiting

Question 6

Clostridium botulinum

Answer 6

G+ rod
obligate anaerobe
spore-forming 
found in soli, ponds and such
home canning and home smoked fish
honey w/ newborns

Question 7

C. botulinum virulence

Answer 7

neurotoxic exotoxin –> prev ACh release –> flaccid paralysis

Question 8

C. botulinum food poisoning

Answer 8

Food --> preformed toxin ingestion
descending paralysis with other Sx
Wound --> lack GI Sx
Infantile --> honey with spores; most common form in US
antibio not recommended