Grain Feeding and the Dissemination of Acid-Resistant Escherichia coli from Cattle

• DOI: 10.1126/science.281.5383.1666
• Publication Date: 2002-07-27T09:43:20Z
• Authors: Francisco Diez-Go...; Todd R. Callaway; Menas G. Kizoulis; James B. Russell
• Keywords: 2. Zero hunger; 0303 health sciences; Rumen; Colon; Colony Count, Microbial; Succinates; Hydrogen-Ion Concentration; Fatty Acids, Volatile; Poaceae; Animal Feed; Culture Media; Diet; 3. Good health; Bacteria, Anaerobic; Random Allocation; 03 medical and health sciences; Escherichia coli; Animals; Cattle; Lactic Acid; Animal Husbandry; Edible Grain

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.