Microbial food borne pathogens. Escherichia coli O157:H7.

Escherichia coli O157:H7 has emerged in the past 20 years as a pathogen of public health importance. Although most E. coli are normal flora in the colons of humans and other warm-blooded animals, several strains are capable of causing disease in humans. In recent years, E. coli O157:H7 and other shiga-like toxin-producing strains have been transmitted via foods and caused disease ranging from bloody diarrhea, and in more severe cases, hemolytic uremic syndrome and thrombocytopenic purpura. The reservoir appears to be cattle and, perhaps, other ruminants. Control is difficult in nonheated foods due to the organism's tolerance to low pH. Only supportive, symptomatic treatment is available for affected humans, and means to eliminate carriage in livestock are not presently available.