AUTHOR=Atassi Fabrice , Pho Viet Ahn Diane L. , Lievin-Le Moal Vanessa 

TITLE=Diverse Expression of Antimicrobial Activities Against Bacterial Vaginosis and Urinary Tract Infection Pathogens by Cervicovaginal Microbiota Strains of Lactobacillus gasseri and Lactobacillus crispatus

JOURNAL=Frontiers in Microbiology

VOLUME=10

YEAR=2019

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2019.02900

DOI=10.3389/fmicb.2019.02900

ISSN=1664-302X

ABSTRACT=<p>We aimed to analyze the strain-by-strain expression of a large panel of antimicrobial activities counteracting the virulence mechanisms of bacterial vaginosis-associated <italic>Prevotella bivia</italic> CI-1 and <italic>Gardnerella vaginalis</italic> 594, pyelonephritis-associated <italic>Escherichia coli</italic> CFT073, and recurrent cystitis- and preterm labor-associated IH11128 <italic>E. coli</italic> by <italic>Lactobacillus gasseri</italic> and <italic>Lactobacillus crispatus</italic> clinical strains, and <italic>L. gasseri</italic> ATCC 9857 and KS 120.1, and <italic>L. crispatus</italic> CTV-05 strains isolated from the cervicovaginal microbiota of healthy women. All <italic>L. gasseri</italic> and <italic>L. crispatus</italic> strains exerted antimicrobial activity by secreted lactic acid, which killed the microbial pathogens by direct contact. Potent bactericidal activity was exerted by a very limited number of resident <italic>L. gasseri</italic> and <italic>L. crispatus</italic> strains showing the specific ability to a strain to produce and release antibiotic-like compounds. These compounds eradicated the microbial pathogens pre-associated with the surface of cervix epithelial cells, providing efficient protection of the cells against the deleterious effects triggered by toxin-producing <italic>G. vaginalis</italic> and uropathogenic <italic>E. coli</italic>. Furthermore, these compounds crossed the cell membrane to kill the pre-internalized microbial pathogens. In addition, all <italic>L. gasseri</italic> and <italic>L. crispatus</italic> cells exhibited another non-strain specific activity which inhibited the association of microbial pathogens with cervix epithelial cells with varying efficiency, partially protecting the cells against lysis and detachment triggered by toxin-producing <italic>G. vaginalis</italic> and uropathogenic <italic>E. coli</italic>. Our results provide evidence of strain-level specificity for certain antimicrobial properties among cervicovaginal <italic>L. gasseri</italic> and <italic>L. crispatus</italic> strains, indicating that the presence of a particular species in the vaginal microbiota is not sufficient to determine its benefit to the host. A full repertory of antimicrobial properties should be evaluated in choosing vaginal microbiota-associated <italic>Lactobacillus</italic> isolates for the development of live biotherapeutic strategies.</p>