Grain feeding and the dissemination of acid-resistant Escherichia coli from cattle.
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.
Diez-Gonzalez
F
F
Division of Biological Sciences, Section of Microbiology, Cornell University and Agricultural Research Service, U.S. Department of Agriculture, Ithaca, NY 14853-8101, USA.
Callaway
T R
TR
Kizoulis
M G
MG
Russell
J B
JB
D000821:Animal Feed; D000822:Animal Husbandry; D000818:Animals; D001421:Bacteria, Anaerobic / Q000254:growth & development; D002417:Cattle / Q000382:microbiology*; D003106:Colon / Q000737:chemistry / Q000382:microbiology*; D015169:Colony Count, Microbial; D003470:Culture Media; D004032:Diet; D002523:Edible Grain; D004926:Escherichia coli / Q000254:growth & development*; D005232:Fatty Acids, Volatile / Q000032:analysis; D006863:Hydrogen-Ion Concentration; D019344:Lactic Acid / Q000032:analysis; D006109:Poaceae; D011897:Random Allocation; D012417:Rumen / Q000737:chemistry / Q000382:microbiology; D013386:Succinates / Q000032:analysis
D003470:Culture Media; D005232:Fatty Acids, Volatile; D013386:Succinates; D019344:Lactic Acid