Staphylococcus aureus, commonly known as Staph, is a common bacterium found on human skin and in nasal passages that can cause food poisoning if ingested. Staph grows within a wide temperature and pH range and produces a heat-stable enterotoxin that causes symptoms like nausea, vomiting, and diarrhea. To prevent food poisoning from Staph, proper handwashing, sanitizing of surfaces and utensils, and safe food handling practices should be followed to avoid contamination of food.

1. Staphyloccal aureus
A brief training on growth,
contamination & prevention.
Kathleen O’Donnell & Shannon LaJuett

2. What is
Staphylococcal
aureus or Staph?
 Staphylococcus aureus (Staph) is a common bacterium found on
the skin, hair, nasal passages & throats of healthy people and
animals.
 S.aureus is a non-motile, small & spherical bacteria which,
appear as grape-like clusters.

3. Growth Parameters?
Temperature range: 4-46 °C (39-115°F) for
Growth and Toxin Production
Optimum Temperature: 37°C (98.6°F)
7°C to 47.8°C
pH range: 4.8-8.0
Lowest reported Aw for growth: ~0.86
Optimum growth of S. aureus occurs at aw of
>0.99
Salt tolerance: 10-20 %
Sugar tolerance: 50-60 %
Tolerance to Nitrites
 This bacterium is aerobic-uses
oxygen.
 S. aureus is one of the most resistant
human pathogens and can survive for
extended periods in a dry state.

4. Why is S. aureus
Important to our Health
& Food Safety?
 Staph can be pathogenic to humans, causing a wide range of infections, as
well as food poisoning, toxic shock syndrome, pneumonia, & wound infection.
 It can be found in foods due to environmental, human, and animal
contamination.
 S.aureus produces a heat stable enterotoxin which causes illness.
 Has been linked to foods such as salads (egg, tuna, chicken, potato, macaroni),
cream filled bakery products, ham, cheese and unpasteurized milk.

5.  Staphylococcal food poisoning is
the illness caused by the Staph
enterotoxin.
 Direct consumption of food
contaminated with S. aureus and
the enterotoxin.
 The illness is relatively mild and
usually lasts from only a few
hours to one day; but it can be
severe. It is not contagious.
 The onset of symptoms usually is
rapid (1 to 6 hrs)! Symptoms
include nausea, abdominal
cramping, vomiting, and diarrhea.
 The CDC reports S. aureus is the
cause of 241,188 illnesses, 1,064
hospitalizations, and 6 deaths
each year.
S. aureus Food Poisoning
& Illness

6. What is an Enterotoxin?
 Staphylococcal enterotoxins (SE) are proteins that are produced as a waste
product.
 They are resistant to heat and digestive enzymes which allows them to pass
through the digestive tract and cause illness.
 Staphylococcal enterotoxin stimulates the emetic reflex center (causes
vomiting- sometimes severe).
 Staphylococcal toxins cannot be destroyed by cooking. Foods may not smell
bad or look spoiled in order to harbor S. aureus and toxins.

7. How Can We Prevent?
• It is important to prevent the contamination of food with
Staphylococcus before the toxin can be produced.
 Wash hands and under fingernails vigorously with soap and
water before handling and preparing food and wear gloves.
 Do not prepare food after touching face or hair or if you have
any infections of the nose or eyes.
 Do not prepare food or product if you have wounds or skin
infections on your hands or wrists.
 Keep product & food-prep areas & utensils clean and
sanitized.
 If food is to be stored longer than two hours, keep hot foods
hot (over 135°F) and cold foods cold (40°F or under).

8. Any Questions?

9. References
1. http://www.cdc.gov/nczved/divisions/dfbmd/diseases/staphylococcal/
2. http://www.foodsafety.unl.edu/pathogens/staph.html
3. http://textbookofbacteriology.net/staph.html
4. http://www.fda.gov/downloads/Food/FoodborneIllnessContaminants/UCM297627