LACTOBACILLUS ACIDOPHILUS DECREASES SALMONELLA TYPHIMURIUM INVASION IN VIVO

The use of probiotics has been suggested to strengthen the non-immunological anti-infective defenses of the gastrointestinal tract. Enteropathogenic bacterial species are common infectious agents in underdeveloped countries. Among these bacteria, Salmonella enterica, the etiological agent of salmonellosis, is considered to be an important agent of diarrheal and systemic disease. In this work, attenuated Salmonella enterica serovar Typhimurium was tested with BALB/c mice treated with Lactobacillus acidophilus strain ATCC 314. A capability of Lactobacillus adhesion to in vitro cultured cells and a significant decrease in the colony-forming units of Salmonella in the Peyer's patches and spleen of lactobacilli-treated mice demonstrated that Lactobacillus interferes with the adhesion, invasion and dissemination processes caused by Salmonella in this murine model, suggesting that the Lactobacillus strain could act as a probiotic agent attenuating the severity of salmonellosis. This work may contribute to studies involving probiotics on the prevention of Salmonella infections. PRACTICAL APPLICATIONS The data indicate that lactobacilli strains may be an alternative prevention against Salmonella infections by contaminated foods. The competitive adhesion and exclusion of a probiotic strain with a pathogen are involved processes in the action of the probiotics in the combat of the intestinal infections. Our results showed that lactobacilli decreased the number of invaders salmonella bacteria in vivo. The action of probiotics using lactobacilli showed beneficial effect on infection of mice by Salmonella. These results contribute for the studies involving probiotics' activities and pathogenicity of enteric diseases.