FDSC3940 Staphylococcus aureus

Staphylococcus aureus

gram positive

facultative anaerobe

cocci

cluster forming

non-spore forming

salt tolerant

0.86 Aw

Infection

caused by the ingestion of live pathogenic bacteria which grow and establish themselves in human GI

growth in food may not be necessary to cause illness

Intoxication

caused by ingestion of food containing toxins made by bacteria during growth

no growth in food = no toxin = no illness

top 5 pathogens contributing to foodborne illness

1. norovirus

2. salmonella

3. clostridium perfingens

4. campylobacter

5. staphylococcus aureus

Staphylococcal Enterotoxin

cells in the food grow to high numbers and produce toxins which are then ingested

differentiated based on immunological reactions

cells are heat sensitive, toxin is very heat stable

1ng/g food can cause symptoms —> HUGE outbreaks

Enterotoxin A

causes more outbreaks

Enterotoxin B

produces more severe symptoms

“Flesh Eating” MRSA

outbreak in slaughterhouse

Methicillin-resistant S. aureus

carry in your nose, found on meat

Staphylococcal Enterotoxin Illness

vomiting

onset: 30min to 8 hr

duration: 1-2 days

late summer and holiday time

most cases not reported —> underreported

Pathology

toxin acts on gut to stimulate emetic response —> trigger vomiting

environmental reservoirs

people are the primary reservoirs of S. aureus

skin, nasal cavity, sweat

associated food for S. aureus

cream filled baked goods, casseroles, vegetable and meat dishes

Making of fish sticks detection methods

test for isolation and enumeration of S. aureus in FDA BAM

culture isolates in broth

mitigation techniques

hygiene and sanitation

time-temperature control

2017 US FDA food code

Potentially hazardous foods = capable of supporting the rapid growth of microbes

Time-temperature control = must be kept below 41F