Staphylococcus aureus is one of the most common causes of foodborne illness worldwide. Besides being present in the environment and animals, this bacterium naturally colonizes human skin and nasal mucosa. It is estimated that approximately one in four healthy individuals carry S. aureus without showing any signs of disease.
Why is S. aureus a concern?
S. aureus is capable of producing a variety of staphylococcal enterotoxins (SEs), among which SEA, SEB, SEC, SED, and SEE are recognized as the major toxins responsible for staphylococcal food poisoning. In particular, enterotoxin A (SEA) is the toxin most frequently implicated in foodborne outbreaks worldwide. These enterotoxins are highly heat-stable and resistant to digestive enzymes, allowing them to remain active even after food has been cooked, thereby posing a significant risk to consumer health.
In addition to enterotoxins, S. aureus can produce other toxins, including hemolysins, leukocidins, and toxic shock syndrome toxin-1 (TSST-1), which contribute to cell damage, immune evasion, and increased pathogenicity of the bacterium.
In addition, S. aureus is capable of forming biofilms on the surfaces of food-processing equipment, utensils, and production environments. Biofilm formation enhances bacterial adhesion and resistance to sanitizers and other adverse conditions, thereby increasing the persistence and transmission of the bacterium throughout the food.
Notably, S. aureus is also recognized as one of the major bacterial pathogens associated with antimicrobial resistance on a global scale. The emergence of methicillin-resistant Staphylococcus aureus (MRSA) and multidrug-resistant (MDR) strains has reduced the effectiveness of antimicrobial therapy for infections in both humans and animals. More importantly, antimicrobial-resistant strains can be transmitted from animals to humans through the food chain, representing a significant threat to food safety and public health.
Picture 1. Staphylococcus aureus
How does S. aureus contaminate food?
Humans are considered the primary reservoir of S. aureus. The bacterium can be transferred to food through the hands of food handlers, as well as by coughing or sneezing during food preparation. Food may also become contaminated through inadequately cleaned utensils, processing surfaces, or improper storage conditions.
S. aureus grows over a wide temperature range (7–48°C), particularly when food remains within the temperature danger zone (5–60°C) for extended periods. Under these conditions, the bacterium can multiply and produce enterotoxins, increasing the risk of food poisoning.
High-risk foods
Food poisoning caused by S. aureus is frequently associated with protein-rich foods that undergo extensive handling during preparation, including:
• Meat and cooked meat products
• Poultry, eggs, and seafood
• Milk and dairy products
• Cream-filled pastries, cakes, and ready-to-eat foods
How can food poisoning be prevented?
S. aureus food poisoning is largely preventable through proper food safety practices:
• Wash hands thoroughly before and during food preparation
• Separate raw foods from ready-to-eat foods
• Cool cooked foods rapidly and store them below 5°C
• Keep hot foods above 60°C before serving
• Regularly clean and sanitize food-contact surfaces and utensils
In the context of increasing antimicrobial resistance and the transmission of pathogens through food, the control of S. aureus should adopt a One Health approach, emphasizing the interconnection among human, animal, and environmental health. Surveillance of the circulation of bacteria and antimicrobial resistance genes throughout the entire food chain, from farm to fork, together with good hygienic practices and maintenance of the cold chain, represents essential measures to ensure food safety and protect public health.
Compiled and translated by: Dr. Vu Quynh Huong, Department of FSQM - Faculty of Food Science Technology
References
Queensland Health (2026). Staphylococcus aureus https://www.health.qld.gov.au/__data/assets/pdf_file/0024/1402656/staphylococcus-aureus.pdf
CDC (2024). About Staph Food Poisoning. https://www.cdc.gov/staph-food-poisoning/about/index.html