Vaginal Microbiota of the Sexually Transmitted Infections Caused by Chlamydia trachomatis and Trichomonas vaginalis in Women with Vaginitis in Taiwan.

Shu-Fang Chiu,Chang-Huei Tsao,Yuan-Ming Yeh,Kuo-Yang Huang,Lih-Chyang Chen,Po-Jung Huang,Petrus Tang,Ching-Yun Huang,Wei-Ning Lin,Hsin-Chung Lin,Lichieh Julie Chu,Chi-Ching Lee,Wei-Hung Cheng

doi:10.3390/microorganisms9091864

Abstract

The three most common sexually transmitted infections (STIs) are Chlamydia trachomatis (CT), Neisseria gonorrhoeae (GC) and Trichomonas vaginalis (TV). The prevalence of these STIs in Taiwan remains largely unknown and the risk of STI acquisition affected by the vaginal microbiota is also elusive. In this study, a total of 327 vaginal swabs collected from women with vaginitis were analyzed to determine the presence of STIs and the associated microorganisms by using the BD Max CT/GC/TV molecular assay, microbial cultures, and 16S rRNA sequencing. The prevalence of CT, TV, and GC was 10.8%, 2.2% and 0.6%, respectively. A culture-dependent method identified that Escherichia coli and Streptococcus agalactiae (GBS) were more likely to be associated with CT and TV infections. In CT-positive patients, the vaginal microbiota was dominated by L. iners, and the relative abundance of Gardnerella vaginalis (12.46%) was also higher than that in TV-positive patients and the non-STIs group. However, Lactobacillus spp. was significantly lower in TV-positive patients, while GBS (10.11%), Prevotella bivia (6.19%), Sneathia sanguinegens (12.75%), and Gemella asaccharolytica (5.31%) were significantly enriched. Using an in vitro co-culture assay, we demonstrated that the growth of L. iners was suppressed in the initial interaction with TV, but it may adapt and survive after longer exposure to TV. Additionally, it is noteworthy that TV was able to promote GBS growth. Our study highlights the vaginal microbiota composition associated with the common STIs and the crosstalk between TV and the associated bacteria, paving the way for future development of health interventions targeting the specific vaginal bacterial taxa to reduce the risk of common STIs.

Highlights

Vaginitis is a common disease for women with vaginal symptoms, including abnormal discharge, odor, irritation, dysuria, itching, or burning [1]
Three hundred and twenty-seven vaginal swabs specimens were originally collected from women with vaginitis who visited hospitals in Northern Taiwan, of which 323 were eligible for the BD Max assay
There was a higher proportion for older women in the Trichomonas vaginalis (TV)-positive group, with 57% of TV-infected patients above 40 years, whereas younger women were predominant in the CT- and GC-positive groups

Summary

Introduction

Vaginitis is a common disease for women with vaginal symptoms, including abnormal discharge, odor, irritation, dysuria, itching, or burning [1]. The most common causes of vaginitis are bacterial vaginosis (BV), vulvovaginal candidiasis (VVC), and trichomoniasis, accounting for approximately 40–50%, 20–25%, and 15–20% of vaginitis cases, respectively [2]. VCC is generally caused by an infection with the fungus Candida albicans [5]. Trichomoniasis is the most common non-viral sexually transmitted infection (STI) caused by the protozoan parasite Trichomonas vaginalis. Co-infection of two pathogens occurs frequently in women with vaginitis. Women with BV are potentially co-infected with Candida spp. and T. vaginalis, with co-infection rates of 20–30% and 60–80%, respectively [6]. More research is necessary to better characterize the cause of inflammatory vaginitis, which is helpful to develop therapies for complete eradication

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