Association of high-risk sexual behaviour with diversity of the vaginal microbiota and abundance of Lactobacillus

Abstract

ObjectiveTo compare the vaginal microbiota of women engaged in high-risk sexual behaviour (sex work) with women who are not engaged in high-risk sexual behaviour. Diverse vaginal microbiota, low in Lactobacillus species, like those in bacterial vaginosis (BV), are associated with increased prevalence of sexually transmitted infections (STIs) and human immunodeficiency virus (HIV) acquisition. Although high-risk sexual behaviour increases risk for STIs, the vaginal microbiota of sex workers is understudied.MethodsA retrospective cross-sectional study was conducted comparing vaginal microbiota of women who are not engaged in sex work (non-sex worker controls, NSW, N = 19) and women engaged in sex work (female sex workers, FSW, N = 48), using Illumina sequencing (16S rRNA, V3 region).ResultsBacterial richness and diversity were significantly less in controls, than FSW. Controls were more likely to have Lactobacillus as the most abundant genus (58% vs. 17%; P = 0.002) and composition of their vaginal microbiota differed from FSW (PERMANOVA, P = 0.001). Six microbiota clusters were detected, including a high diversity cluster with three sub-clusters, and 55% of women with low Nugent Scores fell within this cluster. High diversity was observed by 16S sequencing in FSW, regardless of Nugent Scores, suggesting that Nugent Score may not be capable of capturing the diversity present in the FSW vaginal microbiota.ConclusionsHigh-risk sexual behaviour is associated with diversity of the vaginal microbiota and lack of Lactobacillus. These factors could contribute to increased risk of STIs and HIV in women engaged in high-risk sexual behaviour.

Vaginal microbiome in early pregnancy and subsequent risk of spontaneous preterm birth: a case–control study

“…Lack of association between Nugent score and vaginal microbiome composition in our study is surprising but has previously been reported. 28 Various factors can contribute to this discrepancy in findings, for example, different methods of Gram staining may result in different Nugent score inter-rater reliability 29 and low abundance of bacteria that are better represented by sequencing than Nugent score. 30 Figure 2.…”

Medroxyprogesterone acetate mediated alteration in the vaginal microbiota and microenvironment in a Kenyan sex worker cohort

“…Bacterial DNA was extracted and purified from CVL supernatants as described (21). Four 1 mL aliquots of PBS (negative controls) were randomly selected for gDNA extraction and PCR amplification of the 16S rRNA gene.…”

“…Four 1 mL aliquots of PBS (negative controls) were randomly selected for gDNA extraction and PCR amplification of the 16S rRNA gene. The hypervariable V3 region of 16S was amplified by PCR (21, 51). PCR products were sequenced by McMaster Genomics Facility (Hamilton, ON), Illumina MiSeq platform.…”

“…Importantly, we chose to exclude women with BV because BV is a clinical condition reported to profoundly overshadow the effect of hormones on vaginal biomarkers of microbial health (glycosidases, lectins) in cervico-vaginal lavage (CVL) (22, 23). Furthermore, we (21) and others (19, 20) have demonstrated by 16S ribosomal RNA (rRNA) gene sequencing that women diagnosed with BV by Nugent scoring have inherently diverse VMBs, but women with high diversity VMBs do not always have Nugent scores indicative of BV. Therefore, because symptomatic BV is a clinical condition that could potentially confound the relationship between DMPA and diversity of the VMB, and alter vaginal biomarkers of microbial health the present study excluded women with Nugent scores 7-10, which is used to diagnose clinical BV.…”

“…The VMB alters inflammation in the female genital tract (17), and is implicated in reproductive health and disease. Several factors including ethnicity (12), STIs (18), bacterial vaginosis (BV) (19, 20), and sex work (21) have been reported to impact VMB composition. This study was designed to examine the effect of hormonal contraceptives on the VMB of healthy, asymptomatic Kenyan sex workers to determine if DMPA is associated with changes in the VMB and vaginal microenvironment that might impact their susceptibility to HIV-1.…”