Coloniza o e efeitos no ecossistema digestivo de camundongos gnotobióticos de uma cultura comercial (BIOVICERIN ) de Bacillus cereus

Probiotics are preparations of non-pathogenic microrganisms that promotes beneficial effects to the host. The aim of this work was to test a commercial probiotic containing a Bacillus (BIOVICERINò ), which is indicated for handling chronic and acute enterocolites, against the pathogenic strains of Salmonella Typhimurium, Shigella flexneri and Escherichia coli. Our results have shown no antagonism in vitro of probiotic against the pathogens since no inhibition zone was observed in the used conditions. For evaluation of ecological protection in intestines, GF mice were monoassociated with the probiotic in a single inoculum ten days before challenge with S. Typhimurium. The probiotic was shown to resist the conditions of the gastrointestinal tract and survived in high population levels in intestines. We found a higher survival of the experimental group monoassociated with the probiotic when compared to the control GF group but similar population levels of Salmonella in the feces of both groups. In conclusion, the probiotic BIOVICERINò showed a protection against an experimental infection with Salmonella Typhimurium which was not due to reduction of Salmonella in intestines.