Exploring potential of vaginal Lactobacillus isolates from South African women for enhancing treatment for bacterial vaginosis

• Published in: PLoS pathogens Vol. 16; no. 6; p. e1008559
• Main Authors: Happel, Anna-Ursula, Kullin, Brian, Gamieldien, Hoyam, Wentzel, Nicole, Zauchenberger, Chambrez Z., Jaspan, Heather B., Dabee, Smritee, Barnabas, Shaun L., Jaumdally, Shameem Z., Dietrich, Janan, Gray, Glenda, Bekker, Linda-Gail, Froissart, Remy, Passmore, Jo-Ann S.
• Format: Journal Article
• Language: English
• Published: San Francisco Public Library of Science 01.06.2020; Public Library of Science (PLoS)
• Subjects: Amoxicillin; Antibiotics; Antimicrobial resistance; Authorship; Clindamycin; Durability; Ecology, environment; Gene sequencing; Genital tract; Genomes; Health; Health sciences; HIV; Human immunodeficiency virus; Hydrogen peroxide; Infectious diseases; Lactic acid; Lactobacillus; Life Sciences; Medical research; Medicine; Metronidazole; Microbiota; Pathology; Penicillin; pH effects; Probiotics; Prophages; Rifabutin; Rifampin; Santé publique et épidémiologie; Strains (organisms); Supervision; Symbiosis; Vagina; Vaginosis; Whole genome sequencing; Womens health; United States > US; South Africa; South Africa; female genital tract; vaginal microbiota; bacterial vaginosis; probiotic supplementation; Lactobacillus spp
• ISSN: 1553-7374; 1553-7366; 1553-7374
• DOI: 10.1371/journal.ppat.1008559

Antibiotics continue to be the standard-of-care for bacterial vaginosis (BV), although recurrence rates are high. Vaginal probiotics may improve durability of BV treatment, although few probiotics for vaginal health contain Lactobacillus spp. that commonly colonize the lower female genital tract. Characteristics of vaginal Lactobacillus strains from South African women were evaluated for their probiotic potential in vitro compared to strains from commercial vaginal products, including growth at varying pHs, ability to lower pH, produce D-/L-lactate and H2O2, influence growth of BV-associated Gardnerella vaginalis and Prevotella bivia, adherence to cervical cells and susceptibility to antibiotics. Fifty-seven Lactobacillus strains were purified from cervico-vaginal fluid, including L. crispatus, L. jensenii, L. gasseri, L. mucosae, and L. vaginalis. L crispatus strains grew better at pHs below 4.5 and lowered pH more effectively than other strains. Production of D-/L-lactate and H2O2 varied between Lactobacillus species and strains. Lactobacillus strains generally inhibited P. bivia more uniformly than G. vaginalis isolates. All vaginal Lactobacillus isolates were resistant to metronidazole while susceptibility to clindamycin varied. Furthermore, vaginal Lactobacillus strains tended to be broadly susceptible to penicillin, amoxicillin, rifampicin and rifabutin. Whole-genome-sequencing of five of the best-performing vaginal Lactobacillus strains confirmed their likely safety, due to antimicrobial resistance elements being largely absent, while putative intact prophages were present in the genomes of two of the five strains. Overall, vaginal Lactobacillus strains largely performed better in these in vitro assays than probiotic strains currently used in probiotics for vaginal health. Including the best-performing vaginal Lactobacillus isolates in a region-specific probiotic for vaginal health may result in improved BV treatment options.