Escherichia coli O157:H7 colonization at the rectoanal junction of long-duration culture-positive cattle

Long-duration consistently Escherichia coli O157:H7 culture-positive cattle were euthanized and necropsied. Tissue and digesta from along the gastrointestinal tract (GIT) were cultured for the bacteria and examined histologically for lymphoid character. E. coli O157:H7 was detected only at the rectoanal junction mucosa and not at any other GIT location.