Full Length Research Paper Lack of correlation between H_2O2 production and <i>in vitro</i> anti-staphyloccocal activity of vaginal <i>Lactobacillus</i> spp.

Abstract

Lactobacilli are considered to play important roles in human health as they are known to secrete inhibitory substances to prevent infection by pathogenic organisms. Previously we have isolated 77 strains of Lactobacillus spp. from human vaginas. In this study, using the plate diffusion method, strains showing in vitro antagonistic activity against pathogenic Staphylococcus aureus were screened. Because Lactobacillus spp. are known to produce hydrogen peroxide (H2O2) as an antimicrobial
substance, we attempted to determine if there is a consistent link between in vitro anti-staphylococcal activity and H2O2 production by Lactobacillus spp. A simple quantitative analysis of H2O2 produced by Lactobacillus spp. was performed by a modified spectrophotometric method. A statistically significant correlation was not found between in vitro anti-staphylococcal activity and H2O2 production.