Correlation between Secretor Status and Sexually Transmitted Infection Rates among the Study Participants (n = 280).

<p>Correlation between Secretor Status and Sexually Transmitted Infection Rates among the Study Participants (n = 280).</p

Mucosal Secretor Status among the Study Participants (n = 280).

<p>Mucosal Secretor Status among the Study Participants (n = 280).</p

Socio-demographics characteristics of female sex workers recruited from the Pumwani Majengo Sex Worker cohort in Nairobi, Kenya (n = 280).

<p>Socio-demographics characteristics of female sex workers recruited from the Pumwani Majengo Sex Worker cohort in Nairobi, Kenya (n = 280).</p

Additional file 1: of Effects of HIV-1 infection on malaria parasitemia in milo sub-location, western Kenya

Table S1. Expressions age, sex, malaria parasitaemia and density against HIV status

Non-Sex workers have less bacterial diversity in their vaginal microbiota than sex workers.

<p>Three alpha-diversity metrics were used to compare bacterial richness and diversity within the vaginal microbiota of Non-Sex Workers (NSW, N = 19) as compared to Female Sex Workers (FSW, N = 48) living in the same geographical location. NSW had a significantly less operational taxonomic units (OTUs, an approximation of the number of observed species) than FSW when sequences were rarefied to a depth of 10, 13572, 20353, 27134, 33915, 40696, 47477, and 54288 sequence reads (A). The Chao1 estimated bacterial richness was found to be significantly less in NSW than FSW at 6791, 13572, 20353, 27134, 33915, 40696, 47477, and 54288 sequence reads (B). The Shannon Diversity Index was also significantly lower in NSW than FSW at 10, 6791, 13572, 20353, and 27134 sequence reads (C). NSW (black squares), FSW (open circles). *: P<0.05, **: P< 0.01, *** P< 0.001. Data is presented as mean ± SEM.</p

Heatmap reveals clustering patterns based on community state types.

<p>A heatmap of the top 20 species based on Bray-Curtis dissimilarity distance and PCoA ordination revealed that the vaginal microbiota (columns) of Non-Sex Workers (NSW), and Female Sex Workers (FSW) did not cluster independently, but clustered by community state type (CST). CSTI consisted of women who were <i>L</i>. <i>crispatus</i> dominant (blue, N = 7/67), CSTII were women who were <i>L</i>. <i>gasseri</i> dominant (purple, N = 2/67), CSTIII were <i>L</i>. <i>iners</i> dominant (yellow, N = 10/67), and CSTIV was women with highly diverse vaginal microbiota (green, N = 48/67). All of the women with Nugent Scores 7–10 (dark blue) clustered together in the most diverse CST, regardless of which group (NSW, or FSW) they belonged to. None of the women who were <i>L</i>. <i>crispatus</i>, or <i>L</i>. <i>gasseri</i> dominant had Nugent scores between 4 and 6, but 4 of the women who were <i>L</i>. <i>iners</i> dominant had Nugent scores between 4 and 6. Group, Nugent Score, menstrual cycle phase, and CST are listed below each column. *: resolved to bacterial genus.</p

Non-Sex workers are more likely to have <i>Lactobacillus</i> as the most abundant genus in their vaginal microbiota.

<p>The top 20 bacterial genera in the vaginal microbiota were plotted by relative abundance as taxa bar charts and compared between Non-Sex Workers (NWS, N = 19) (A) and Female Sex Workers (FSW, N = 48) (B). Each bar represents the vaginal microbiota of one woman. Each colour represents a different genus of bacteria, as indicated in the legend. Species of <i>Lactobacillus</i> are indicated in grey/coloured patterns as per legend. Vaginal microbiota are ordered left to right in descending order of the relative abundance of <i>Lactobacillus</i>, and women to the left of the dashed lines have <i>Lactobacillus</i> as the most abundant genus in their vaginal microbiota (proportion listed as the percentage in the grey box) (C). NSW were significantly more likely (P = 0.002) to have <i>Lactobacillus</i> as the most abundant genus in their vaginal microbiota (A) as compared to FSW (B). Pairwise PERMANOVA revealed significant differences in the composition (β-diversity) of the NSW vs. FSW (PERMANOVA P = 0.001) vaginal microbiota (A vs. B). Nugent score, Shannon Diversity (at 6791 reads) and menstrual cycle stage are indicated below the taxa bar chart (C). None of the women with a Nugent Score 7–10 had <i>Lactobacillus</i> as the most abundant genus in their vaginal microbiota. *: Resolved to family level.</p

Principle coordinate analysis demonstrates clustering by relative abundance of <i>Lactobacillus</i>.

<p>PCoA plots demonstrate the beta-diversity of the vaginal microbiota of Non-Sex Workers (NSW, N = 19), and Female Sex Workers (FSW, N = 48). The vaginal microbiota did not appear to cluster by group (NSW vs. FSW; A). When coloured by the relative abundance of <i>Lactobacillus</i> one main cluster dominant in <i>Lactobacillus</i> were revealed (B). The stronger intensity of blue indicates greater relative abundance. Some clustering by Nugent Score (C) was also observed (0–3: grey, 4–6: light blue, 7–10: dark blue). The vaginal microbiota did not appear to strongly cluster by menstrual cycle phase (D) (Proliferative: light pink, Secretory: light purple, Hormonal Contraceptives: purple, Unknown: black). Axes = eigenvalues, a metric whose magnitude indicates the amount of variation captured in the PCoA axis.</p

Association of high-risk sexual behaviour with diversity of the vaginal microbiota and abundance of <i>Lactobacillus</i>

<div><p>Objective</p><p>To 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 <i>Lactobacillus</i> 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.</p><p>Methods</p><p>A 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).</p><p>Results</p><p>Bacterial richness and diversity were significantly less in controls, than FSW. Controls were more likely to have <i>Lactobacillus</i> 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.</p><p>Conclusions</p><p>High-risk sexual behaviour is associated with diversity of the vaginal microbiota and lack of <i>Lactobacillus</i>. These factors could contribute to increased risk of STIs and HIV in women engaged in high-risk sexual behaviour.</p></div

Six distinct vaginal microbiota clusters are found within this group of women.

<p>The gap statistic, which gives an estimation of how well ‘k’ (number of clusters) fits the data, was calculated (A). The number of clusters present in the data is indicated by the plateau in the gap statistic, which occurred at 6. A cluster dendrogram was created in order to better visualize the clusters (B). Three sub-clusters within community state type (CST) IV (green, high diversity) were identified. One sub-cluster had <i>Streptococcus</i> as the dominant genus, another had <i>G</i>. <i>vaginalis</i>, while the third had <i>Prevotella/Sneathia/BVAB1</i> and was more diverse in terms of the dominant species. In general, the previously described CSTs clustered together within the dendrogram. CSTI (blue): <i>L</i>. <i>cripatus</i> dominant, CSTII (purple): <i>L</i>. <i>gasseri</i> dominant, CSTIII (yellow): <i>L</i>. <i>iners</i> dominant, CSTIV (green): highly diverse. *: resolved to bacterial genus.</p