Which strain of E. coli is most commonly associated with foodborne illness outbreaks?

E. coli O157:H7 is the strain most commonly associated with foodborne illness outbreaks due to its ability to produce a potent Shiga toxin, which can lead to severe gastrointestinal illness and complications such as hemolytic uremic syndrome (HUS). This strain is notorious for being linked to various outbreaks from undercooked beef, raw milk, contaminated vegetables, and other food sources.

The prevalence of E. coli O157:H7 in foodborne outbreaks is significantly higher compared to other strains, which may cause illness but are less frequently implicated in large-scale outbreaks. Its recognition as a public health concern has led to extensive food safety monitoring and reporting, cementing its place as the most common strain associated with these outbreaks.

In contrast, while other strains such as E. coli O26, O104:H4, and O111 can also cause foodborne illnesses, they have not been reported as frequently in major outbreaks, making them less prominent in discussions on foodborne pathogens.