HPLC Analysis of lactic acid inhibition of Salmonella typhi and Escherichia coli responsible of diarrheal diseases in Algeria: Alternative treatment

Several works were shown the effect in vitro of lactic acid bacteria on pathogenic strains responsible for human gastroenteritis. This work aims to seek strains of lactic acid bacteria could inhibit in vitro the growth of pathogenic bacteria involved in gastroenteritis and analyze organic acids responsible of this inhibition. Interactions in agar medium were conducted between lactic acid bacteria in pure or mixed culture and pathogenic bacteria (E. coli and S. typhi). The best inhibition zones of E.coli are found with Lp (diameter = 10 mm) and St*+ Lb*+ Bl (diameter = 10 mm). For S.typhi, the combinations St3 + Lb1+ Bl and St2 + Lp +Bl have the major inhibitory effect (diameters of8 mm and7 mm, respectively). HPLC method confirmed the presence of lactic acid in bacterial cultures used in this study.