Does the Staphylococcus Aureus Toxin Withstand Freezing?

Staphylococcus aureus toxins are resistant to cooking and freezing.

Staphylococcus aureus is a toxin-producing bacterium. Ingestion of food contaminated with the toxin causes Staph aureus food poisoning. According to Ohio State University Family and Consumer Sciences, Staph aureus is the most common cause of foodborne illness. Killing the bacteria does not destroy the disease-causing toxin.

Dose

Staphylococcus aureus produces an enterotoxin, a poison that causes inflammation of the digestive tract. The FDA reports a toxin dose less than 1.0 microgram in contaminated food produces staphylococcal intoxication symptoms. Such levels are achieved when Staph aureus populations exceed 100,000 per gram of contaminated food.

Sources

According to Medline Plus, Staph aureus contamination is most common in foods served at room or refrigerator temperature, including custards or cream-filled desserts, salads containing mayonnaise, poultry, eggs and casseroles. Food handlers are the most common cause of contamination.

Management

Although Staph aureus bacteria grow best at body temperature, Dr. Julie A. Albrecht of the University of Nebraska says they can multiply rapidly in food held at room temperature. According to Albrecht, thorough cooking destroys the bacteria, but the toxin is extremely resistant to heat, freezing and refrigeration. Proper hand washing techniques and sanitation of preparation surfaces and utensils help control contamination. Holding foods at 41 degrees or below slows bacterial growth, thereby limiting toxin production.

References

• Ohio State University Extension Fact Sheet: Staphylococcus Aureus - A Most Common Cause
• Medline Plus: Staph Aureus Food Poisoning
• University of Nebraska Cooperative Extension Food Safety: Stapylococcus Aureus
• FDA: Bad Bug Book - Staphylococcus Aureus

Resources

• University of Georgia: Recognition and Prevention of Staphylococcal Enterotoxins