Influence of the probiotic Escherichia coli strain Nissle 1917 on the growth of different pathogenic bacteria isolated from patients with diarrhea

The aim of this study was to investigate the in vitro inhibitory effect of probiotic E.coli Nissle 1917 (EcN) strain against pathogenic bacteria isolated from patients with diarrhea. Probiotics are viable microorganisms that are shown to have beneficial effects on human health. EcN is a typical example of probiotics; however, there are few reports of it being administered for treatment of diarrhea.Patients and The inhibitory effect of EcN was assessed against bacteria associated with diarrhea, including 30 diarrheagenic E.coli strains, 10 Salmonella spp, 10 Clostridium difficile and 10 Campylobacter spp, using spot method inoculation. The microcin sensitive strain (E.coli K12 H 5316) was used as control. In vitro growth inhibition was recorded in none of cultured bacterial samples. The inhibitory activity of EcN on different bacteria probably relies on different in vivo complementary mechanisms.