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ARS Home » Plains Area » Clay Center, Nebraska » U.S. Meat Animal Research Center » Meat Safety and Quality » Research » Publications at this Location » Publication #244180
Title: Evaluation of a Direct-Fed Microbial Product Effect on the Prevalence and Load of Escherichia coli O157:H7 in Feedlot Cattle

Author
item Arthur, Terrance
item Bosilevac, Joseph - Mick
item Kalchayanand, Norasak - Nor
item Wells, James - Jim
item Shackelford, Steven
item Wheeler, Tommy
item KOOHMARIE, MOHAMMAD - Former ARS Employee

Submitted to: Journal of Food Protection
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/14/2009
Publication Date: 2/20/2010
Citation: Arthur, T.M., Bosilevac, J.M., Kalchayanand, N., Wells, J., Shackelford, S.D., Wheeler, T.L., Koohmarie, M. 2010. Evaluation of a Direct-Fed Microbial Product Effect on the Prevalence and Load of Escherichia coli O157:H7 in Feedlot Cattle. Journal of Food Protection. 73(2):366-371.

Interpretive Summary: Direct fed microbials have been identified as potential pre-harvest interventions for the reduction of foodborne bacterial pathogens such as E. coli O157:H7. This study evaluated the efficacy of a direct fed microbial consisting of a spore-forming bacterium as an antimicrobial intervention strategy for the reduction of prevalence and load of Escherichia coli O157:H7 in feces and on hides of feedlot cattle. During the 84-day feeding period, there were no significant differences between treatments for either hide or fecal prevalence of E. coli O157:H7 or for the percentage of animals that were shedding E. coli O157:H7 at high levels in their feces or harboring E. coli O157:H7 at high levels on their hides. Also, the direct fed microbial treatment had no effect on the rate of weight gain. The direct fed microbial tested would not be an effective pre-harvest intervention against E. coli O157:H7.

Technical Abstract: Direct fed microbials (DFM) have been identified as potential pre-harvest interventions for the reduction of foodborne bacterial pathogens such as E. coli O157:H7. This study evaluated the efficacy of a direct fed microbial (DFM) consisting of Bacillus subtilis strain 166 as an antimicrobial intervention strategy for the reduction of prevalence and load of Escherichia coli O157:H7 in feces and on hides of feedlot cattle. Cattle (n=526) were divided among 16 feedlot pens. Half of the pens received the DFM and the other eight pens did not. Hide and fecal samples were collected from each animal on days 28, 63, and 84 of the feeding trail. Over the course of the 84-day feeding period, there were no significant differences observed between treatments for either hide or fecal prevalence of E. coli O157:H7 or for the percentage of animals that were shedding E. coli O157:H7 at high levels (greater than 200 CFU/g) in their feces or harboring E. coli O157:H7 at high levels (greater than 40 CFU/cm2) on their hides. Also, there was no significant difference between the average daily gains for the treated and control groups with both groups averaging 1.3 kg per day. We concluded that the DFM tested would not be an effective pre-harvest intervention against E. coli O157:H7.