USE OF A MIXTURE OF PROBIOTIC STRAINS AGAINST SHIGA TOXIN‐PRODUCING ESCHERICHIA COLI (STEC) COLONIZATION IN SHEEP

Abstract

Shiga toxin‐producing Escherichia coli (STEC) strains are food‐borne pathogens that cause human diseases, and ruminants are usually important reservoirs of STEC. The first step of enteric infection is colonization of the host's gut mucosal surface by pathogenic strains of bacteria. Probiotic bacteria can decrease the severity of infection by competing for receptors and nutrients and by synthesizing an acid that creates an unfavorable environment for the growth of several bacterial species. The aim of this study was to determine whether the inoculation of sheep with a mixture containing 3 × 108 (CFU) of Bacillus cereus, Lactobacillus acidophilus and Enterococcus faecium strains decrease the colonization of STEC. Sheep that received oral inoculums containing 2 × 109 viable bacteria of STEC carriers of stx1, stx2 and eae genes were compared with others groups that did not receive inoculums. When mixture was inoculated together with the STEC, the numbers of STEC in a population were lower than the group did not receive during the 3a, 5a, 6a and 7a weeks post‐inoculation. Thus, we conclude that this mixture likely presented a potential protective effect in reducing colonization by STEC and can be used as an alternative method to decrease STEC infection in sheep, thereby reducing transmission to humans.Financial Support: Fapesp Process: 2009/14923‐8