Understanding STEC: Information You Need to Know
Foodborne illnesses caused by infectious bacteria, viruses, and parasites, and chemical intoxicating substances affect one in six Americans every year. According to the U.S. Department of Agriculture (USDA), these illnesses costs the US economy more than $15.6 billion annually. Further, the Centers for Disease Control and Prevention (CDC) estimates 3,000 deaths per year due to foodborne diseases.
Several food pathogens like Salmonella, Campylobacter, Vibrio cholerae, and Escherichia coli are the culprits behind this problem. Although most E. coli strains are harmless, Shiga toxin-producing E. coli (STEC), in particular, is a group of E. coli strains most associated with foodborne outbreaks. As food producers, you have the responsibility to ensure your consumers don't become a statistic. Read on to learn more about STEC and other food pathogens and how to eliminate them from your products.
Impact of STEC on food
Foods most often linked to STEC are raw meat, fresh produce, flour, unpasteurized milk and other dairy products. In the dairy industry, STEC is a major concern because of its high virulence. A dose of only five to fifty cells is needed to cause illness. The bacteria exhibit pathogenicity via infective and toxin-producing mechanisms. Infants, young children, the elderly, and other immunocompromised individuals are very susceptible to the disease.
Optimal conditions for STEC's growth
E. coli strains thrive between 10-46°C, but some strains, including STEC, can grow in milk products at as low as 6.5°C due to their inherent genetic mechanisms. However, they don't have extreme heat-resistant genes. This is why pasteurization of milk at 72°C for 15 seconds is recommended to inactivate STEC strains.
6 most common foodborne pathogens
Aside from STEC, here are the most common pathogens that can cause foodborne diseases.
Escherichia coli
E. coli is a species of commensal human intestinal bacteria that co-exists with the human host in a mutually beneficial relationship. However, it also has several strains involved in foodborne diseases, including ones that cause major foodborne outbreaks around the world. The foods linked to E. coli are meats, fresh produce, raw, or unpasteurized milk/dairy products and unpasteurized juices like fresh apple cider. STEC is the E. coli strain often associated with foodborne diseases and outbreaks. One of the most notable STEC strains is E. coli O157:H7, which frequently leads to large outbreaks in the meat and produce industry.
Norovirus
Norovirus infects people through contaminated food and water, but it can also be transferred from person to person. The virus spreads easily through contaminated food and surfaces. Like E. coli, they can also cause outbreaks most often from November to April.
Campylobacter
This species of bacteria can enter the body through contaminated food and water. The most common carriers of Campylobacter are unpasteurized milk and other dairy products or raw and undercooked poultry. There were also some reports of finding Campylobacter isolates in seafood and produce related items. They cause sporadic foodborne diseases but rarely large outbreaks.
Salmonella
Salmonella causes two kinds of foodborne diseases: Salmonellosis and Enteric fever. The foods often linked to these diseases are meats, poultry, eggs, fruits, vegetables, spices, and nuts.
Listeria
Listeria infects fewer people and rarely causes outbreaks, but it is one of the leading causes of death from foodborne illness. It is linked to eating raw foods or unpasteurized or raw milk and cheeses. The manifestations of Listeriosis range from mild symptoms like nausea and vomiting to more severe ones like meningitis or miscarriage and preterm labor for pregnant women.
Hepatitis A Virus
Hepatitis A is caused by eating or drinking contaminated food and water. The most recent outbreaks are linked to contaminated water, shellfish, frozen fruit and salads. The disease starts from two to four weeks after ingestion of the virus, but it is usually self-limiting in one to two weeks if the patient is immunocompetent.
How will foodborne pathogens affect your consumers' health?
Foodborne diseases result from the ingestion of food and water contaminated with foodborne pathogens. The most common types are listed above. This results in a wide array of symptoms from mild discomfort to life-threatening ones. Anyone is susceptible to foodborne diseases, but immunocompromised individuals like pregnant women, young children, and older people have a higher risk of contracting them.
Although common, these illnesses are largely preventable with proper food handling, food safety testing and public health education.
How can you mitigate the problem?
To eliminate STEC and other pathogens in your food products, follow your local guidelines on food safety for suppliers. Further, you can partner with a trusted food testing laboratory, like Eurofins, for thorough microbiological testing that includes analytical services to detect pathogenic microbes and their toxins. In addition to food testing services, Eurofins also offers challenge tests, characterization of microorganisms in products, shelf-life studies, and hygiene parameters.
By partnering with Eurofins, you can gain specific, actionable recommendations on how to prevent microbiological contamination and ensure the safety and quality of your products. For more information, contact your local Eurofins laboratory.
