Antagonistic Activity ofLactobacillusIsolates againstSalmonella typhi In Vitro

Abstract

Background. Enteric fever is a global health problem, and rapidly developing resistance to various drugs makes the situation more alarming. The potential use ofLactobacillusto control typhoid fever represents a promising approach, as it may exert protective actions through various mechanisms.Methods. In this study, the probiotic potential and antagonistic activities of 32Lactobacillusisolates againstSalmonella typhiwere evaluated. The antimicrobial activity of cell free supernatants ofLactobacillusisolates, interference ofLactobacillusisolates with theSalmonellaadherence and invasion, cytoprotective effect ofLactobacillusisolates, and possibility of concurrent use of testedLactobacillusisolates and antibiotics were evaluated by testing their susceptibilities to antimicrobial agents, and their oxygen tolerance was also examined.Results. The results revealed that twelveLactobacillusisolates could protect againstSalmonella typhiinfection through interference with both its growth and its virulence properties, such as adherence, invasion, and cytotoxicity. TheseLactobacillusisolates exhibited MIC values for ciprofloxacin higher than those ofSalmonella typhiand oxygen tolerance and were identified asLactobacillus plantarum.Conclusion. The testedLactobacillus plantarumisolates can be introduced as potential novel candidates that have to be subjected forin vivoand application studies for treatment and control of typhoid fever.