School of Environmental and Biological Sciences, Rutgers State University, New Brunswick, NJ, USA.
J Appl Microbiol. 2012 Sep;113(3):714-22. doi: 10.1111/j.1365-2672.2012.05376.x. Epub 2012 Jul 24.
To determine the mechanism of action of antimicrobial protein, lactosporin, against Gardnerella vaginalis and to evaluate its safety in vitro.
Bacillus coagulans ATCC 7050 was grown at 37°C for 18 h. The cell-free supernatant was concentrated 10-fold and screened for antimicrobial activity against indicator strain Micrococcus luteus. The mode of action of lactosporin was determined by measuring the potassium release and monitoring the changes in transmembrane potential (Δψ) and transmembrane pH (ΔpH) of the sensitive cells. Lactosporin caused the efflux of potassium ions from M. luteus cells and dissipation of ΔpH in G. vaginalis, while it had no effect on the Δψ. The safety of lactosporin was evaluated by using EpiVaginal(™) ectocervical (VEC-100) tissue model. Over 80% of the cells in the vaginal tissue remained viable after exposure to lactosporin for 24 h.
Lactosporin potentially exerts its antimicrobial activity by selective dissipation of ΔpH and/or by causing leakage of ions from the sensitive cells. Safety studies suggest that lactosporin is a noncytotoxic antimicrobial for vaginal application.
This study revealed that lactosporin is an effective and safe antimicrobial preparation with potential application for the control of bacterial vaginosis.
确定抗微生物蛋白乳链菌肽对阴道加德纳菌的作用机制，并评估其体外安全性。
在 37°C 下培养凝结芽孢杆菌 ATCC 7050 18 小时。将无细胞上清液浓缩 10 倍，并筛选对指示菌株藤黄微球菌的抗菌活性。通过测量钾离子的释放以及监测敏感细胞的跨膜电位（Δψ）和跨膜 pH（ΔpH）的变化来确定乳链菌肽的作用模式。乳链菌肽导致藤黄微球菌细胞中钾离子的外流和 ΔpH 的耗散，而对 Δψ 没有影响。通过使用 EpiVaginal(™)阴道外颈（VEC-100）组织模型评估乳链菌肽的安全性。在暴露于乳链菌肽 24 小时后，阴道组织中超过 80%的细胞仍然存活。
乳链菌肽通过选择性耗散 ΔpH 和/或导致敏感细胞中离子泄漏来发挥其抗菌活性。安全性研究表明，乳链菌肽是一种非细胞毒性的阴道应用抗菌药物。
本研究表明，乳链菌肽是一种有效且安全的抗菌制剂，具有控制细菌性阴道病的潜在应用。
