Grain feeding and the dissemination of acid-resistant Escherichia coli from cattle.

Division of Biological Sciences, Section of Microbiology, Cornell University and Agricultural Research Service, U.S. Department of Agriculture, Ithaca, NY 14853-8101, USA.
Science (Impact Factor: 31.48). 10/1998; 281(5383):1666-8.
Source: PubMed

ABSTRACT The gastric stomach of humans is a barrier to food-borne pathogens, but Escherichia coli can survive at pH 2.0 if it is grown under mildly acidic conditions. Cattle are a natural reservoir for pathogenic E. coli, and cattle fed mostly grain had lower colonic pH and more acid-resistant E. coli than cattle fed only hay. On the basis of numbers and survival after acid shock, cattle that were fed grain had 10(6)-fold more acid-resistant E. coli than cattle fed hay, but a brief period of hay feeding decreased the acid-resistant count substantially.

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