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Escherichia coli O157:H7 populations in ruminants can be reduced by orange peel product feeding

Callaway, Todd R., Carroll, Jeffery A., Arthington, John D., Edrington, Tom S., Rossman, Michelle L., Carr, Mandy A., Krueger, Nathan A., Ricke, Steven C., Crandall, Phil, Nisbet, David J.
Journal of food protection 2011 v.74 pp. 1917
Escherichia coli O157, antimicrobial properties, byproducts, cecum, corn, diet, disease control, experimental design, intestinal microorganisms, orange peels, orange pulp, pathogens, pellets, rectum, rumen, sheep, sheep feeding
Foodborne pathogenic bacteria such as Escherichia coli O157:H7 are threats to the safety of beef. Citrus peel and dried orange pulp are by-products from citrus juice production that have natural antimicrobial effects and are often incorporated into least-cost ration formulations for beef and dairy cattle. This study was designed to determine if orange peel and pulp affected E. coli O157:H7 populations in vivo. Sheep (n ~ 24) were fed a cracked corn grain–based diet that was supplemented with a 50-50 mixture of dried orange pellet and fresh orange peel to achieve a final concentration (dry matter basis, wt/wt) of 0, 5, or 10% pelleted orange peel (OP) for 10 days. Sheep were artificially inoculated with 1010 CFU of E. coli O157:H7 by oral dosing. Fecal shedding of E. coli O157:H7 was measured daily for 5 days after inoculation, after which all animals were humanely euthanized. At 96 h postinoculation, E. coli O157:H7 shedding was reduced (P , 0.05) in sheep fed 10% OP. Populations of inoculated E. coli O157:H7 were reduced by OP treatment throughout the gastrointestinal tract; however, this reduction reached significant levels in the rumen (P , 0.05) of sheep fed 10% OP diets. Cecal and rectal populations of E. coli O157:H7 were reduced (P , 0.05) by inclusion of both 5 and 10% OP diets. Our results demonstrate that orange peel products can be used as a preharvest intervention strategy as part of an integrated pathogen reduction scheme.