The vaginal microbiome of South African pregnant women living with human immunodeficiency virus (HIV) with and without Chlamydia trachomatis infection.

BACKGROUND: Chlamydia genital infections continue to be a serious health concern globally. Previous studies have reported that Chlamydia trachomatis infection alters the vaginal microbiota of infected women. This study investigated differences in the vaginal microbiome of South African pregnant women living with HIV with and without C. trachomatis infection. METHODS: This was a cross-sectional study among 385 pregnant women, recruited from the King Edward VIII Hospital in Durban, South Africa. C. trachomatis was detected using the Applied Biosystems™ TaqMan® Assays. A total of 40 samples, 20 C. trachomatis positive and 20 C. trachomatis negative, were selected for sequencing. The sequencing of the vaginal microbiome was performed using the PacBio platform. Statistical analysis was performed on IBM SPSS version 26. RESULTS: The prevalence of C. trachomatis infection was 12.2% (47/385). The genus Gardnerella (32.14% vs. 24.02%) and species in the genus Gardnerella (31.97% vs. 24.03%) were more abundant in the C. trachomatis-infected group compared to the uninfected group. Lactobacillus iners were also more abundant in the C. trachomatis-infected women (28.30%) compared to the uninfected women. However, these observed patterns did not reach statistical significance. Discriminant analysis showed that the class Alpha-Proteobacteria; order Bacillales; family Enterococcaceae; the genera Enhydrobacter, Enterococcus, and Parabacteroides; Enterococcus spp.; and Pseudomonas stutzeri significantly contributed to a model separating C. trachomatis-infected women from the uninfected group (p < 0.05). CONCLUSION: The organisms and taxa that significantly contributed to separating the vaginal microbiota of C. trachomatis-infected women from the uninfected women in this study cohort have not been previously observed in association with C. trachomatis infection or the vaginal microbiota. Future studies in larger cohorts that will investigate the role of these microorganisms in C. trachomatis infection and the vaginal microbiota are required.

Lack of resistance to macrolides in Mycoplasma genitalium detected in South African pregnant women.

BACKGROUND: Azithromycin regimens have been considered first-line treatment for Mycoplasma genitalium (M. genitalium), a sexually transmitted infection (STI) associated with adverse pregnancy outcomes. However, recent years have seen rapid emergence of macrolide resistance in M. genitalium as a result of widespread administration of azithromycin. Currently, there are limited data on macrolide resistance in pregnant women from KwaZulu-Natal (KZN), South Africa. This study investigated the prevalence of M. genitalium and emerging patterns of macrolide resistance in pregnant women from KZN. METHODS: This was a sub-study of a larger study which involved laboratory-based detection of STIs in pregnant women. In the main study, pregnant women provided urine samples for detection of STIs. For this study, deoxyribose nucleic acid (DNA) extracted from stored urine was used to determine emerging macrolide resistance by amplification of the 23S ribosomal ribonucleic acid (rRNA) gene of M. genitalium by polymerase chain reaction (PCR) and sequencing of amplicons to identify mutations associated with resistance. The Allplex™ MG & AziR assay was used as a confirmatory assay. RESULTS: The prevalence of M. genitalium in pregnant women was 5.9% (13 out of 221). Sequencing of PCR amplicons did not reveal the presence of the A2059G and A2058G mutations associated with macrolide resistance. These findings were confirmed by the Allplex™ MG & AziR assay. CONCLUSION: Despite the lack of resistance to macrolides in this study population, continued antimicrobial resistance surveillance for M. genitalium in pregnant women is important because azithromycin is now part of the South African national STI syndromic management guidelines for vaginal discharge syndrome.