Fig. 5

Model for enzymatic activity in glycosylation and glycogen degradation in Lactobacillus crispatus. Schematic representation of the vaginal environment with either LVM or DVM. Our comparative genomics analysis revealed a glycosyltransferase gene that was more common in Lactobacillus crispatus strains isolated from LVM (red bacteria) and DVM (low abundance of red lactobacilli, diverse bacterial population in multiple colors and forms, thinner mucus layer). We hypothesize that L. crispatus in DVM exploits this genetic variation to allow for (a higher) variation in cell wall glycoconjugates providing a mechanism for L. crispatus to persist at low levels in DVM and remain stealth from the immune system. Another finding of this work describes the ability of L. crispatus strains to utilize glycogen as a food source, which is associated with the presence of a full-length pullulanase gene (red dots on cell wall of L. crispatus). Abbreviations: LVM: Lactobacillus-dominated vaginal microbiota; DVM: dysbiotic vaginal microbiota, LC: Langerhans cell, CK: cytokines