Prevalence of Escherichia coli O157:H7 in Cattle and During Processing

Escherichia coli is a phenotypically and genomically diverse and versatile bacterial species. Commensal E. coli are valuable to warm-blooded animals (including humans) as part of the intestinal microflora, but pathogenic E. coli can cause a variety of diseases in the same hosts. Human illnesses associated with pathogenic E. coli include infections of the urinary tract, blood stream, meninges, or intestinal tract. The disease or virulence attributes (e.g., invasiveness) of pathogenic E. coli have been used to group them, using acronyms ending in “EC” for E. coli. For example, strains that cause diarrhea have been referred to as diarrheagenic E. coli, or DEC strains (Whittam et al., 1993). General information on pathogenic E. coli is available in Ørskov (1984) and Nataro and Kaper (1998).