Antimicrobial properties of Lactobacillus cell‐free supernatants against multidrug‐resistant urogenital pathogens

Abstract

The healthy vaginal microbiota is dominated by Lactobacillus spp., which provide an important critical line of defense against pathogens, as well as giving beneficial effects to the host. We characterized L. gasseri 1A‐TV, L. fermentum 18A‐TV, and L. crispatus 35A‐TV, from the vaginal microbiota of healthy premenopausal women, for their potential probiotic activities. The antimicrobial effects of the 3 strains and their combination against clinical urogenital bacteria were evaluated together with the activities of their metabolites produced by cell‐free supernatants (CFSs). Their beneficial properties in terms of ability to interfere with vaginal pathogens (co‐aggregation, adhesion to HeLa cells, biofilm formation) and antimicrobial activity mediated by CFSs were assessed against multidrug urogenital pathogens (S. agalactiae, E. coli, KPC‐producing K. pneumoniae, S. aureus, E. faecium VRE, E. faecalis, P. aeruginosa, P. mirabilis, P. vulgaris, C. albicans, C. glabrata). The Lactobacilli tested exhibited an extraordinary ability to interfere and co‐aggregate with urogenital pathogens, except for Candida spp., as well as to adhere to HeLa cells and to produce biofilm in the Lactobacillus combination. Lactobacillus CFSs and their combination revealed a strong bactericidal effect on the multidrug resistant indicator strains tested, except for E. faecium and E. faecalis. The antimicrobial activity was maintained after heat treatment but decreased after enzymatic treatment. All Lactobacilli showed lactic dehydrogenase activity and production of D‐ and L‐lactic acid isomers on Lactobacillus CFSs, while only 1A‐TV and 35A‐TV released hydrogen peroxide and carried helveticin J and acidocin A bacteriocins. These results suggest that they can be employed as a new vaginal probiotic formulation and bio‐therapeutic preparation against urogenital infections. Further, in vivo studies are needed to evaluate human health benefits in clinical situations.

Genome mining reveals polysaccharide-degrading potential and new antimicrobial gene clusters of novel intestinal bacterium Paenibacillus jilinensis sp. nov.

“…Supernatants were collected and filter-sterilized with a 0.22 μm filter (Millipore, USA). The antimicrobial activity of CFS was evaluated initially according to the effect of CFS on the viability of the pathogenic bacteria [ 44 ] and appropriate modifications. Briefly, overnight pathogenic cultures were sub-cultured in TSB at 37℃ to logarithmic phase.…”

Insights From the Lactobacillus johnsonii Genome Suggest the Production of Metabolites With Antibiofilm Activity Against the Pathobiont Candida albicans

“…In this work, we showed that, like other Lactobacillus species (Kang et al, 2018;Jang et al, 2019;Scillato et al, 2021), L. johnsonii displays anticandidal properties, reducing C. albicans growth and ability to transition into hyphae and establish biofilms on abiotic surfaces. We found that the MT4 strain shows strong dose-dependent anticandidal activity, particularly in the biofilm growth phase.…”

Clustering Analysis of the Multi-Microbial Consortium by Lactobacillus Species Against Vaginal Dysbiosis Among Ecuadorian Women

“…L. jensenii showed an individual probiotic effect against AV. Although the protective effect of L. gasseri against BV is well known ( Scillato et al., 2021 ), its individual effect is overlapped when other Lactobacillus species are present in the same cluster, in particular L. iners and L. crispatus . However, the present study has several limitations, such as the absence of longitudinal analysis between vaginal infections and sociodemographic/behavioral variables or lactobacilli, only one vaginal sample was collected of each volunteer, and the lack of quantitative data.…”

“…Vaginal microbiota balances the health state of women through its ability to prevent potential dysbiosis or infections ( Pacha-Herrera et al., 2020 ; Joseph et al., 2021 ). Healthy women usually show a diversity of anaerobic and aerobic microorganisms in the vaginal epithelium ( Borges et al., 2013 ), in which lactobacilli are the dominant species and act as a protective barrier to prevent pathogenic colonization ( Di Cerbo et al., 2016 ; Scillato et al., 2021 ). However, the vaginal colonization by different lactobacilli species depends also on their ability to produce antimicrobial compounds, such as hydrogen peroxide, lactic acid, and bacteriocin-like substances ( Borges et al., 2013 ; Castillo-Juárez et al., 2022 ).…”