E. coli O157:H7 has competition from other STECs

For years, O157:H7 was the pathogenic strain of E. coli known to wreak havoc, now others can too

Recently there have been foodborne illnesses associated with non-O157:H7 strains of Escherichia coli (E. coli). E. coli is found in many different forms, including Shiga toxin-producingEscherichia coli (STEC). The most commonly associated strain of E. coli with foodborne illness is O157:H7.

There have been foodborne illness outbreaks over the last ten years in several countries and the U.S. related to non-O157 STECs. Research is ongoing to identify pathogenic STECs and increase rapid methods of testing for and isolating these strains. Other illnesses have been caused by O157 and other STECs that have a serotype of nonmotile (NM). The NM serotypes do not have flagella or express the H7 (or other) antigen. E. coli O157:HM was recently implicated in a ground beef recall in Michigan. E. coli O104:H4 was the culprit in a foodborne illness outbreak in Germany and France and was traced back to fenugreek seeds according to information from the CDC. There are over 100 other STECS. The United States Department of Agriculture Food Safety and Inspection Service identified testing methods for six non-O157 STECs, including: O26, O45, 0103, O111, O121, and O145.

These pathogens are always changing and it is important to recognize the risk that could be associated with various foods, not only raw ground beef. Other cases have shown fruit, fruit juices, lake water, leafy raw milk, vegetables, and more to be the culprit for E. coli related illnesses. Food safety at all levels – on the farm, in the processing plant, and at the point of preparation – is an ever-changing target. Testing in itself cannot provide food that is 100% safe. Prevention and intervention are also keys to providing safe food. 

Any E. coli infection can be spread through the ingestion of feces, human or animal, in addition to eating raw or undercooked contaminated foods. Nausea, vomiting, diarrhea, bloody stool and other symptoms can be caused by STECs. Some of these cases turn into more severe illness such as hemolytic uremic syndrome (HUS; http://www.mayoclinic.com/health/hemolytic-uremic-syndrome/DS00876) that can lead to kidney failure. The Centers for Disease Control and Prevention (CDC) indicates that an estimated 265,000 infections from STEC occur annually with approximately 64% of those being caused by non-O157 strains. Many infections go unreported, therefore, estimation is reported by CDC. Children, elderly, and immunocompromised individuals are at greatest risk for contracting an illness from STECs and other pathogens.

The best way to prevent illness is to thoroughly wash your hands with soap and water (http://www.cdc.gov/features/handwashing/), properly cook your meat (http://news.msue.msu.edu/news/article/pork_does_not_have_to_be_well_done), especially ground meats like hamburger (http://news.msue.msu.edu/news/article/cook_hamburger_to_160_degrees), and avoid cross contamination with raw foods.

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