Figure 6
Inhibition of Gardnerella vaginalis growth by Lactobacillus culture supernatants. (A) Growth of G. vaginalis was determined by measuring the optical density of cultures at a wavelength of 600 nm (OD600), after culture with lactobacilli supernatants in duplicate within the same assay for 24 h at 37 °C. The fold change in growth of G. vaginalis only cultures was compared to those cultured with lactobacilli supernatants using an unpaired two-tailed t-test. (B) Colony forming units (CFU)/ml of G. vaginalis pretreated with lactobacilli supernatants on brain heart infusion (BHI) agar after incubation for 48 h at 37 °C were assessed in duplicate within the same assay. (C,D) Lactobacillus jensenii (LJ)5, L. mucosae (LM)2 and L. gasseri (LG)1 were used to determine the mechanism underlying the inhibition of G. vaginalis by lactobacilli supernatant in triplicate within the same assay. (C) The effects of hydrogen peroxide reduction by catalase and (D) bacteriocin degradation by proteolytic enzymes in Lactobacillus culture supernatants on the growth of G. vaginalis. Lines indicate means and error bars indicate the standard deviations of technical replicates. Student’s t-tests were used for comparisons. **Adjusted p-values < 0.05 were considered statistically significant. CFU: colony forming units, LC: L. crispatus, LV: L. vaginalis, Cat: catalase, Enz = proteolytic enzymes.
