Quantitation of all Four Gardnerella vaginalis Clades Detects Abnormal Vaginal Microbiota Characteristic of Bacterial Vaginosis More Accurately than Putative G. vaginalis Sialidase A Gene Count

Abstract

Background Bacterial vaginosis (BV) is a vaginal disorder characterized by a depletion of the normal lactobacillus-dominant microbiota and overgrowth of mainly anaerobic bacteria. Objectives The study aimed to evaluate the distribution and abundance of the Gardnerella vaginalis clades and sialidase A gene in vaginal samples from Russian women, and investigate if the G. vaginalis sialidase A gene count detects an abnormal vaginal microbiota characteristic of BV more accurately than G. vaginalis load. Methods Vaginal samples from 299 non-pregnant patients of gynecological clinics were examined using Nugent scores and G. vaginalis clade and sialidase A gene quantitative real-time polymerase chain reactions (PCRs). Discriminatory power for BV microbiota was evaluated with receiver operating characteristic (ROC) analysis. Results The vaginal microbiota was characterized by Nugent scores as normal, intermediate, and BV microbiota in 162, 58, and 79 women, respectively. G. vaginalis clades 1, 2, 3, 4, and the sialidase A gene were detected in 56% (51–62%), 40% (34–45%), 20% (16–25%), 94% (91–96%), and 70% (64–75%) of vaginal samples, respectively. The frequency and abundance of clades 1, 2, 4, and the sialidase A gene as well as clade multiplicity were significantly associated with abnormal microbiota. The sialidase A gene was present in all multi-clade samples, in all single-clade samples comprising clades 1, 2, and 3, and in four of 84 (5% [2–12%]) samples comprising clade 4 only. Total G. vaginalis load showed significantly higher discriminatory power for abnormal microbiota than sialidase A gene count (areas under ROC curves 0.933 vs. 0.881; p = 0.0306). Conclusions Quantifying all four G. vaginalis clades discriminates between BV microbiota and normal microbiota more accurately than measuring G. vaginalis sialidase A gene. Clade 4 is strongly associated with BV microbiota, despite most clade 4 strains lacking the sialidase A gene.

Resolution and Cooccurrence Patterns of Gardnerella leopoldii, G. swidsinskii, G. piotii, and G. vaginalis within the Vaginal Microbiome

“…The relationship between Gardnerella abundance and Nugent score is not surprising, as the presence of Gardnerella "morphotypes" on Gram-stained slides of vaginal specimens is part of the calculation of the clinical score (3). The lack of association of G. leopoldii with Nugent category is interesting in that this species was previously investigated together with G. swidsinskii as cpn60 subgroup A/clade 4, which was found to be associated with Nugent category (14,23,31). These species are very closely related phylogenetically ( Fig.…”

Co-infection with trichomonas vaginalis increases the risk of cervical intraepithelial neoplasia grade 2–3 among HPV16 positive female: a large population-based study

“…As a sexually transmitted infectious agent, TV is found to cause local inflammation, and it affects the clearance of hr-HPV and contributes to cervical lesion detection in several research, but it is controversial [8]. Some studies have demonstrated a correlation between vaginal infection and the carcinogenicity of hr-HPV, but most of them are small-scale researches, and their conclusions are inconsistent [5,[9][10][11][12][13][14][15][16]. This research is with the most massive scale and the most comprehensive investigation about the correlation between cervical hr-HPV infection, CIN/ ICC, and the vaginal microbiome.…”

Resolution and co-occurrence patterns ofGardnerella leopoldii,Gardnerella swidsinskii,Gardnerella piotiiandGardnerella vaginaliswithin the vaginal microbiome

“…The relationship between Gardnerella abundance and Nugent score is not surprising, as the presence of Gardnerella “morphotypes” on Gram stained slides of vaginal specimens is part of the calculation of the clinical score [3]. The lack of association of G. leopoldii with Nugent category is interesting in that this species was previously investigated together with G. swidsinskii as cpn60 subgroup A/clade 4 which was found to be associated with Nugent category [14, 34, 40]. These species are very closely related phylogenetically (Figure 1), and were only resolved by Vaneechoutte et al [13] by MALDI-TOF and whole genome comparison, so the specific factors responsible for their apparently different relationships with the microbiological definition of BV remain to be identified.…”