Vaginal Microbiota Molecular Profiling in Women with Bacterial Vaginosis: A Novel Diagnostic Tool

Abstract

Bacterial vaginosis (BV) is a most common microbiological syndrome. Multiplex next-generation sequencing (NGS) or molecular tests allow a complete and accurate vaginal microbiota profiling in order to determine the primary causative agent. Due to the high costs and limited availability of NGS, the multiplex real-time PCR draws more attention. The present study aimed to evaluate the microbial composition and dominant lactobacilli species in non-pregnant women with bacterial vaginosis using a multiplex RT-PCR test and determine its diagnostic significance. In total, 331 women complaining of vaginal discharge were included. BV was confirmed upon clinical examination and Nugent criteria. A real-time PCR test was carried out with a new Femoflor test, which identifies opportunistic bacteria, STD pathogens, and some viruses. According to the results, the rate of lactobacilli is significantly reduced in BV-affected patients when compared to healthy women. Moreover, the rate of L. crispatus significantly decreases, while the rate of L. iners remains high. Among obligate anaerobic bacteria, Gardnerella vaginalis was the most prevalent in women with BV. The Femoflor test demonstrated high sensitivity and specificity for diagnosing BV. Moreover, the test allows the identification of infection in women with intermediate vaginal microbiota, as well as STD pathogens, and viruses. Thus, the application of real-time PCR tests can be effectively used in vaginal microbiota evaluation in women with BV, intermediate vaginal microbiota, and healthy women. In addition, this test may be used as an alternative to the Amsel criteria and Nugent scoring method in diagnosing BV.

Keywords: Lactobacillus crispatus; Lactobacillus iners; bacterial vaginosis; real-time PCR; vaginal microbiota.

Figure 1

Comparative analysis of bacterial load in different types of vaginal microbiota.

Figure 2

The detection rate and the number of obligate anaerobes in women with different types of vaginal microbiota. B/P/P-Bacteroides spp./Porphyromonas spp./Prevotella spp.; S/L/F-Sneathia spp./Leptotrihia spp./Fusobacterium spp.; M/V/D-Megasphaera spp./Veilonella spp./Dialister spp.; C/L-Clostridium spp./Lachnobacterium spp.

Figure 3

Detection rate of lactobacilli species in different types of vaginal microbiota.

Figure 4

Dominant members of vaginal lactobacilli species in women with and without BV.

Figure 5

Detection rate of Candida spp., Candida albicans, and mollicutes in women with and without BV.

Figure 6

ROC analysis for Femoflor test in BV prediction.