Endocervical and vaginal microbiota in South African adolescents with asymptomatic Chlamydia trachomatis infection

Christina Balle,Anna-Lise Williamson,David A Lewis,Smritee Dabee,Venessa Maseko,Shaun L Barnabas,Shameem Z Jaumdally,Heather B Jaspan,Katie Lennard,Jo-Ann S Passmore,Linda-Gail Bekker,Melanie A Gasper,Zizipho Z A Mbulawa

doi:10.1038/s41598-018-29320-x

Abstract

Adolescent girls and young women represent a key risk group for sexually transmitted infections (STIs). The vaginal microbiota is thought to play an important role in susceptibility to STIs such as Chlamydia trachomatis. We compared the microbiota of the lateral vaginal wall and endocervix, and assessed associations with C. trachomatis infection in South African adolescents. The endocervical and vaginal lateral wall microbiota were characterized by amplifying and sequencing the V4 region of the 16S rRNA gene and C. trachomatis diagnosed using molecular methods. Of the 72 girls included, 30 had asymptomatic C. trachomatis infections. Three major vaginal community types were identified; one Lactobacillus crispatus, one L. iners and one diverse, Gardnerella vaginalis dominant. The microbiota of the endocervix was significantly different from that of the lateral wall in terms of diversity. There were many differentially abundant taxa between the endocervix and lateral vaginal wall, including Achromobacter spanius and Enterococcus faecium. Women with C. trachomatis had higher relative abundance of G. vaginalis and other anaerobes. In this African adolescent cohort, significant differences between the lateral vaginal wall and endocervical microbiota diversity and composition were evident, although neither were strongly associated with C. trachomatis infection.

Highlights

Chlamydia trachomatis is an obligate intracellular bacterium and the leading cause of bacterial sexually transmitted infections (STIs) worldwide with young women being at risk[1]
Low-diversity communities dominated by a single Lactobacillus species (Lactobacillus crispatus, L. gasseri, L. iners, or L. jensenii) and one to two high-diversity communities, comprised of a mixture of anaerobic bacteria associated with Bacterial vaginosis (BV), are described[3,4,5,6]
Few molecular studies have evaluated the relationship between prevalent C. trachomatis infections and the composition of cervicovaginal microbiota and none have focused on African adolescents, a group at extreme risk for STIs

Summary

Introduction

Chlamydia trachomatis is an obligate intracellular bacterium and the leading cause of bacterial sexually transmitted infections (STIs) worldwide with young women being at risk[1]. The composition of the endocervical microbiota may be of greater importance when looking at the relationship between commensal bacteria and STIs, as the cervix is the main site of infection for several pathogens including N. gonorrhoeae and C. trachomatis[14]. Molecular studies characterizing bacterial communities at different anatomical sites throughout the FGT have generated varying results with regards to microbial homogeneity[16,17,18]. Few molecular studies have evaluated the relationship between prevalent C. trachomatis infections and the composition of cervicovaginal microbiota and none have focused on African adolescents, a group at extreme risk for STIs. we compared the endocervical and vaginal microbiota and evaluated their association with C. trachomatis infection in young South African females from a high risk community

Methods

Results

Conclusion