LAUSR

Background: Herpes simplex virus type 2 (HSV‐2) infectious disease is one of the most common viral sexually transmitted diseases. As regards, vaginal lactobacilli play an important role in protecting host against the urogenital pathogens; here we assessed the potential antiviral activity of Lactobacillus crispatus against HSV‐2 infection in vitro. Methods: Both Vero and HeLa cell lines were treated by L. crispatus before, during and after HSV‐2 infection. The pre‐incubation assay was also performed for the evaluating of virus adsorption by L. crispatus. Virus titer reduction in each stage was determined by a plaque reduction assay. Results: L. crispatus significantly decreased the infectivity of the HSV‐2 in initial steps on both cell lines; however, no significant inhibition was ascertained during adsorption and multiplication process. The lactobacilli adhere on Vero cells two‐fold stronger than HeLa and subsequently protect the Vero cells nearly 2.5 fold higher than HeLa cell against the virion. Co‐incubation of HSV‐2 with bacterial cells prior to virus inoculation significantly decreased the virus titer. Conclusion: L. crispatus appears to inhibit the entry of the virus into cells by trapping HSV‐2 particles. In addition, formation of L. crispatus microcolonies in the cell surface could block HSV‐2 receptors and prevent viral entry to cells in initial infection steps.