EFFECT OF ORAL TREATMENT WITH BIFIDOBACTERIUM ANIMALIS VAR. LACTIS IN EXPERIMENTAL INFECTION WITH SALMONELLA TYPHIMURIUM IN GNOTOBIOTIC AND CONVENTIONAL MICE

Ariane Katiuscia Santos Martins (UFMG); Flaviano dos Santos Martins (UFMG); Danielle Alves Gomes (UFMG); Samir Andrade Deus Elian (UFMG); Angélica Thomaz Vieira (UFMG); Mauro Martins Teixeira (UFMG); Denise Carmona Cara Machado (UFMG); Regina Maria Nardi Drummond (UFMG); Jacques Robert Nicoli (UFMG)

Second the World Health Organization (WHO), probiotic can be defined as a preparation containing live microorganisms that, when administered in sufficient amounts, confers a beneficial effect to the host. Among the microorganisms more frequently utilized as probiotic we could mention the genus Bifidobacterium. The present work had the aim to investigate the oral treatment with two strains of Bifidobacterium animalis var. lactis, in gnotobiotic and conventional mice, challenged with Salmonella enterica sorovar Typhimurium. Utilizing tests of antagonism in vitro was observed that the two strains were able to produce antagonistic substance in vitro against pathogenic microorganisms. In ex vivo antagonism test were produced antagonistic substances only against three of the ten microorganisms tested. In addition the Bifidobacterium strains were able to colonize and maintain in high numbers in the digestive tract of gnotobiotic mice. The two strains had a low intensity translocation (only to Peyer’s Patch and mesenteric linfonodes) and didn’t cause any histological lesion in none of the organs analyzed of the monoassociated mice. Bifidobacterium animalis var lactis BB-12 e BB-12 free were able to reduce the numbers of Salmonella in the gnotobiotic mice challenged with the pathogen and treated with the probiotics, but only BB-12 free was able to confer a protection in the ileum of animals against the oral challenge with S. Typhimurium and a decrease in mortality of animals pre-treated with it. Higher levels of sIgA (P < 0.05) and IL-10 (P = 0.055) were observed only in BB-12 free mono-associated mice when compared to germ-free group. We could conclude that, among the parameters analyzed, the strains BB-12 free exhibited the more desirable characteristics to be used as a probiotic.