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. 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. 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.

中文翻译：

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来自阴道松脆乳杆菌BC1的生物表面活性剂，有望成为干扰念珠菌粘附的有前途的药物。

乳杆菌属。健康妇女的阴道微生物区系占主导地位，有助于预防泌尿生殖系统和性传播感染。它们在阴道中的保护作用可以由乳杆菌细胞本身，代谢产物或细菌成分介导，能够干扰病原体的粘附和感染性。外阴念珠菌病（VVC）是一种常见的生殖器感染，是由机会性念珠菌菌种过度生长引起的。包括白色念珠菌，光滑念珠菌，克鲁斯念珠菌和热带念珠菌。唑类抗真菌药在解决VVC和预防反复感染方面并不总是有效的，因此，基于阴道益生菌的替代抗念珠菌药物变得越来越重要。目前的工作旨在化学表征从阴道乳杆菌crispitatus菌株L. crispatus BC1分离的生物表面活性剂（BS），并通过体外和体内试验研究其对念珠菌的安全性和抗粘连/抗菌活性。从阴道松散乳杆菌BC1分离出的BS具有非均匀脂肽分子的特征，其临界胶束浓度值为2 mg / mL，具有良好的乳化和粘膜粘附特性​​。浓度为1.25 mg / mL时，BS无细胞毒性，主要通过排除机制降低了念珠菌菌株粘附于人宫颈上皮细胞的能力。此外，在小鼠实验模型中的阴道内（i.va.）接种BS是安全的，并且不会干扰阴道细胞学，组织学和可培养的阴道微生物群。如果是i.va。挑战白色念珠菌小鼠时，BS能够减少白细胞流入。这些结果表明，BS来自阴道L。