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ARS Home » Research » Publications at this Location » Publication #114241
Title: COMMERCIAL PROBIOTICS ARE NOT EFFECTIVE FOR SHORT-TERM CONTROL OF EHEC O157INFECTION IN BEEF CATTLE

Author
item Keen, James
item ELDER, ROBERT - FORMER ARS EMPLOYEE

Submitted to: International Symposium and Workshop on Shiga Toxin ... Escherichia coli
Publication Type: Abstract Only
Publication Acceptance Date: 8/11/2000
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: Many intervention strategies have been proposed for preharvest control of enterohemorrhagic E. coli O157:H7/non-motile (EHEC O157) infection in live cattle, including dietary management, vaccination, competitive exclusion, hygienic environmental manipulations, and testing with removal of infected animals. Under the hypothesis that short-term probiotic use will prevent and/or eliminate EHEC O157 fecal shedding in finished (slaughter-ready) beef cattle by competitive exclusion, we evaluated two commercial probiotics (PB) using field trial methodology in EHEC O157 naturally- exposed and infected feedlot beef cattle. PB#1 contained four lactic acid bacteria at 300 million cfu/dose, while PB#2 contained vitamins, minerals, yeast and four lactic acid bacteria at 1.5 billion cfu/dose. Finished feedlot cattle (n=99) in three pens were randomly assigned to PB#1, PB#2, or Control (no probiotic) groups. Probiotic doses were given orally on days 0 and 1. All cattle were fecal cultured for EHEC O157 on days 0 and 7 On day 0, overall pre-probiotic baseline fecal EHEC O157 prevalence was 29% (29/99). On day 7, overall fecal EHEC O157 prevalence was 37% (37/99). Day 0 to day 7 fecal EHEC O157 prevalence by treatment group was: Control: 9/33 to 13/33; PB#1: 12/33 to 15/33; PB#2: 8/33 to 9/33. Thus, fecal prevalence increased over 7 days of follow-up by 12% in controls, by 9% in PB#1, and by 3% in PB#2. A multiple logistic regression model using individual animal EHEC O157 fecal shedding status on day 7 as outcome and adjusting for a random pen effect and EHEC O157 shedding status on day 0 as potential confounders confirmed no probiotic treatment effect versus controls. We conclude that there is neither benefit nor detriment from use of either commercial probiotic on beef cattle fecal EHEC O157 shedding.