Escherichia coli
Occur as normal flora in the lower part of intestine of warm blooded animals
Toxin producing strains of E. coli are important agents of food-borne illnesses
Emerging pathogen E. coli O157:H7; dairy cattle considered as reservoirs.
Prevalence of enterotoxigenic E. coli in bulk tank milk
1989 1.4% Canada
1997 3.9% Germany
1997 12.3 % Canada
1997 3.8% USA ……...
1998 0.87% Canada