Biosurfactant from vaginal Lactobacillus crispatus BC1 as a promising agent to interfere with Candida adhesion

Abstract

Background: Lactobacillus spp. dominating the vaginal microbiota of healthy women contribute to the prevention of urogenital and sexually transmitted infections. Their protective role in the vagina can be mediated by Lactobacillus cells themselves, metabolites or bacterial components, able to interfere with pathogen adhesion and infectivity. Vulvovaginal candidiasis (VVC) is a common genital infection, caused by the overgrowth of opportunistic Candida spp. including C. albicans, C. glabrata, C. krusei and C. tropicalis. Azole antifungal drugs are not always efficient in resolving VVC and preventing recurrent infections, thus alternative anti-Candida agents based on vaginal probiotics have gained more importance. The present work aims to chemically characterize the biosurfactant (BS) isolated from a vaginal Lactobacillus crispatus strain, L. crispatus BC1, and to investigate its safety and antiadhesive/antimicrobial activity against Candida spp., employing in vitro and in vivo assays. Results: BS isolated from vaginal L. crispatus BC1 was characterised as non-homogeneous lipopeptide molecules with a critical micellar concentration value of 2 mg/mL, and good emulsification and mucoadhesive properties. At 1.25 mg/mL, the BS was not cytotoxic and reduced Candida strains' ability to adhere to human cervical epithelial cells, mainly by exclusion mechanism. Moreover, intravaginal (i.va.) inoculation of BS in a murine experimental model was safe and did not perturb vaginal cytology, histology and cultivable vaginal microbiota. In the case of i.va. challenge of mice with C. albicans, BS was able to reduce leukocyte influx. Conclusions: These results indicate that BS from vaginal L. crispatus BC1 is able to interfere with Candida adhesion in vitro and in vivo, and suggest its potential as a preventive agent to reduce mucosal damage occasioned by Candida during VVC.

Effect of 17β-estradiol on a Human Vaginal Lactobacillus Crispatus Strain

“…The decrease of surface tension was dose related but was only signi cant in the presence of estradiol 10 -6 M. Many Lactobacilli are known to produce molecules with biosurfactant activity, including glycoproteins such as surlactin 47 . Production of biosurfactant by vaginal L. crispatus was recently demonstrated 48 . The molecule appears as a complex non-homogenous lipopeptide since sophisticated chemical techniques, including Fourier transformed infrared spectroscopy and electron spray mass spectrometry were not su cient to determine its complete structure 48 .…”

“…Production of biosurfactant by vaginal L. crispatus was recently demonstrated 48 . The molecule appears as a complex non-homogenous lipopeptide since sophisticated chemical techniques, including Fourier transformed infrared spectroscopy and electron spray mass spectrometry were not su cient to determine its complete structure 48 . This L. crispatus biosurfactant has interesting properties, including low cytotoxicity, stimulation of mucins mucoadhesion and even antagonism against Candida spp.…”

“…This L. crispatus biosurfactant has interesting properties, including low cytotoxicity, stimulation of mucins mucoadhesion and even antagonism against Candida spp. adhesion 48 . In this regard, the effect of 17βestradiol on L. crispatus biosurfactant production is of interest since this species is one of the major species of the vaginal microbiota [8][9] and this could have direct consequences in the preservation of vaginal homeostasis.…”

Vaginal microbiota and the potential of Lactobacillus derivatives in maintaining vaginal health

“…Recently, BS from L. crispatus BC1 also demonstrated significant in vitro anti-adhesion activity against C. albicans through exclusion mechanism on human cervical cancer HeLa cell line and in vivo immunomodulatory activity by reducing the leukocyte influx (i.e. prevent mucosal damage) caused by C. albicans in mice [ 253 ]. Based on these findings, it is conceivable that the mechanism of action of Lactobacillus BS involves adhesion interruption rather than killing of the invading pathogens.…”

Lactobacillus crispatus BC1 Biosurfactant Delivered by Hyalurosomes: An Advanced Strategy to Counteract Candida Biofilm

“…In a recent study, a BS isolated from vaginal Lactobacillus crispatus BC1 was found to interfere with the adhesion of various Candida isolates to human cervical epithelial cells; furthermore, BS intravaginal inoculation in a murine experimental model was shown to be safe and effective in reducing leukocyte influx in the case of C . albicans infection [ 9 ]. L. crispatus species plays a crucial role in maintaining vaginal eubiosis, exerting beneficial properties that have already been extensively addressed in previous studies [ 10 , 11 , 12 , 13 , 14 ].…”