Submitted to: Critical Reviews in Microbiology
Publication Type: Review Article
Publication Acceptance Date: 4/27/2001
Publication Date: N/A
Citation: Interpretive Summary:
Technical Abstract: The presence of E. coli O157:H7 in cattle illustrates the complex, interrelated nature of the environment, livestock production practices, food safety, and the science of microbiology particularly microbial ecology. Enterohemorrhagic E. coli, including E. coli O157:H7, can cause severe human diseases which can be debilitating and life threatening. Cattle are currently considered to be the definitive source for E. coli O157:H7 in the food supply but this view may be simplistic and incomplete. E. coli O157:H7 appears widespread among U.S. cattle herds while individual animal prevalence is low and transient. Most individual animals appear to be a transient reservoir for E. coli O157:H7 although the issue of carrier animals still remains unresolved. Epidemiological studies of the cattle production system have not clearly identified risk factors or management practices that affect E. coli O157:H7 prevalence in cattle feces. The problem of E. coli O157:H7 increases during the summer and fall months but the environmental factors which contribute to this increase are poorly understood. Possible environmental factors which may influence E. coli O157:H7 shedding in cattle include livestock feed and waste handling practices as well as insects, and microbial interactions in soil and water. Studies of E. coli O157:H7 ecology in cattle and the environment have been limited, but they suggest that a consideration of other independent, environmental sources of this microbe seems appropriate. The natural ecology of cholera may serve as a useful environmental model for pursuing additional environmental research on the occurrence and transmission of E. coli O157:H7 in nature.