Comparison of lower genital tract microbiota in HIV-infected and uninfected women from Rwanda and the US

Vaginal Microbiome Metagenome Inference Accuracy: Differential Measurement Error according to Community Composition

Several studies have compared metagenome inference performance in different human body sites; however, none specifically reported on the vaginal microbiome. Findings from other body sites cannot easily be generalized to the vaginal microbiome due to unique features of vaginal microbial ecology, and investigators seeking to use metagenome inference in vaginal microbiome research are "flying blind" with respect to potential bias these methods may introduce into analyses. We compared the performance of PICRUSt2 and Tax4Fun2 using paired 16S rRNA gene amplicon sequencing and whole-metagenome sequencing data from vaginal samples from 72 pregnant individuals enrolled in the Pregnancy, Infection, and Nutrition (PIN) cohort. Participants were selected from those with known birth outcomes and adequate 16S rRNA gene amplicon sequencing data in a case-control design. Cases experienced early preterm birth (<32 weeks of gestation), and controls experienced term birth (37 to 41 weeks of gestation). PICRUSt2 and Tax4Fun2 performed modestly overall (median Spearman correlation coefficients between observed and predicted KEGG ortholog [KO] relative abundances of 0.20 and 0.22, respectively). Both methods performed best among Lactobacillus crispatus-dominated vaginal microbiotas (median Spearman correlation coefficients of 0.24 and 0.25, respectively) and worst among Lactobacillus iners-dominated microbiotas (median Spearman correlation coefficients of 0.06 and 0.11, respectively). The same pattern was observed when evaluating correlations between univariable hypothesis test P values generated with observed and predicted metagenome data. Differential metagenome inference performance across vaginal microbiota community types can be considered differential measurement error, which often causes differential misclassification. As such, metagenome inference will introduce hard-to-predict bias (toward or away from the null) in vaginal microbiome research. IMPORTANCE Compared to taxonomic composition, the functional potential within a bacterial community is more relevant to establishing mechanistic understandings and causal relationships between the microbiome and health outcomes. Metagenome inference attempts to bridge the gap between 16S rRNA gene amplicon sequencing and whole-metagenome sequencing by predicting a microbiome's gene content based on its taxonomic composition and annotated genome sequences of its members. Metagenome inference methods have been evaluated primarily among gut samples, where they appear to perform fairly well. Here, we show that metagenome inference performance is markedly worse for the vaginal microbiome and that performance varies across common vaginal microbiome community types. Because these community types are associated with sexual and reproductive outcomes, differential metagenome inference performance will bias vaginal microbiome studies, obscuring relationships of interest. Results from such studies should be interpreted with substantial caution and the understanding that they may over- or underestimate associations with metagenome content.

Molecular Identification of Cervical Microbes in HIV-Negative and HIV-Positive Women in an African Setting Using a Customized Bacterial Vaginosis Microbial DNA Quantitative PCR (qPCR) Array

Bacterial vaginosis (BV) is a common polymicrobial vaginal disorder that is associated with sexually transmitted infections (STIs), including HIV. Several studies have utilized broad-range 16S rRNA gene PCR assays with sequence analysis to characterize cervicovaginal bacterial communities of women with healthy and diseased conditions. With the high burden of BV and STIs among African women, there is a need for targeted PCR assays that can rapidly determine the true epidemiological profile of key cervical microbes, including BV-associated bacteria, and a need to explore the utility of such assays for microbiological diagnosis of BV. Here, we used a taxon-directed 16S rRNA gene quantitative PCR (qPCR) assay to examine the prevalences and determinants of specific cervical microbes among African women with and without HIV infection. Cervical samples were collected using a cytobrush from 162 women (aged ≥30 years) attending a community-based clinic in Eastern Cape, South Africa. The samples were screened for specific microbes (i.e., STIs, emerging sexually transmitted pathogens [pathobionts], and BV-associated bacteria) using a customized bacterial vaginosis microbial DNA qPCR array. Statistical analyses were performed using GraphPad Prism v6.01. Chi-square/Fisher's exact tests were used to evaluate the determinants associated with specific cervical microbes. Only 145 women had any detectable microbes and were included in the analysis. Lactobacillus iners (62.8%) and specific BV-associated bacteria, namely, Gardnerella vaginalis (58.6%), Atopobium vaginae (40.7%), and the pathobiont Ureaplasma parvum (37.9%), were the most prevalent microbes. Hierarchical clustering analysis revealed that 42.8% of the women (62/145) had a diverse array of heterogeneously distributed bacteria typically linked to BV. Women with detectable Lactobacillus species, specifically Lactobacillus crispatus and Lactobacillus jensenii, and to a lesser extent L. iners, had very low prevalence of BV-associated bacteria. Although the cumulative burden of STIs/pathobionts was 62.8%, Chlamydia trachomatis (3.4%), Neisseria gonorrhoeae (4.8%), and Trichomonas vaginalis (4.8%) were detected at low rates. HIV infection was associated with the presence of STIs/pathobionts (P = 0.022) and L. iners (P = 0.003). Prevalent STIs/pathobionts were associated with having multiple partners in the past 12 months (n ≥ 2, P = 0.015), high number of lifetime sexual partners (n ≥ 3, P = 0.007), vaginal sex in the past month (P = 0.010), and decreasing age of women (P = 0.005). C. trachomatis was associated with increasing age among HIV-positive women (P = 0.016). The pathobiont Ureaplasma urealyticum was inversely associated with age of women in the whole cohort (P = 0.018). The overall prevalence of STIs/pathobionts was high and was associated with HIV infection and sexual behavior. Our study helps us to understand the epidemiological trend of STIs and pathobionts and highlights the need to understand the impact of sexual networks on STI and pathobiont transmission and prevention among women in an African setting. IMPORTANCE Bacterial vaginosis (BV), whose etiology remains a matter of controversy, is a common vaginal disorder among reproductive-age women and can increase the risk for sexually transmitted infections (STIs). African women bear a disproportionately high burden of STIs and BV. Using a targeted quantitative PCR (qPCR) assay, a customized bacterial vaginosis microbial DNA qPCR array, we examined the prevalences and determinants of key cervical microbes, including BV-associated bacteria and emerging sexually transmitted pathogens (pathobionts) among women of African descent aged between 30 and 75 years. High-risk behaviors were associated with a higher prevalence of STIs/pathobionts, suggesting the need to better understand the influence of sexual networks on STI and pathobiont transmission and prevention among women. Our molecular assay is important in the surveillance of BV-associated bacteria, pathobionts, and STIs as well as diagnostic microbiology of BV. Furthermore, our research contributes to a better understanding of the epidemiology of STIs and pathobionts in Africa.

Associations Between Vaginal Bacteria and Bacterial Vaginosis Signs and Symptoms: A Comparative Study of Kenyan and American Women

Background

Bacterial colonization and associations with bacterial vaginosis (BV) signs and symptoms (Amsel criteria) may vary between populations. We assessed relationships between vaginal bacteria and Amsel criteria among two populations.

Methods

Kenyan participants from the placebo arm of the Preventing Vaginal Infections (PVI) trial and participants from a Seattle-based cross-sectional BV study were included. Amsel criteria were recorded at study visits, and the vaginal microbiota was characterized using 16S rRNA gene sequencing. Logistic regression models, accounting for repeat visits as appropriate, were fit to evaluate associations between bacterial relative abundance and each Amsel criterion.

Results

Among 84 PVI participants (496 observations) and 220 Seattle participants, the prevalence of amine odor was 25% and 40%, clue cells 16% and 37%, vaginal discharge 10% and 52%, elevated vaginal pH 69% and 67%, and BV 13% and 44%, respectively. BV-associated bacterium 1 (BVAB1) was positively associated with all Amsel criteria in both populations. Eggerthella type 1, Fannyhessea (Atopobium) vaginae, Gardnerella spp., Sneathia amnii, and Sneathia sanguinegens were positively associated with all Amsel criteria in the Seattle study, and all but discharge in the PVI trial.

Conclusions

Core vaginal bacteria are consistently associated with BV signs and symptoms across two distinct populations of women.

Human microbiota research in Africa: a systematic review reveals gaps and priorities for future research

BACKGROUND

The role of the human microbiome in health and disease is an emerging and important area of research; however, there is a concern that African populations are under-represented in human microbiome studies. We, therefore, conducted a systematic survey of African human microbiome studies to provide an overview and identify research gaps. Our secondary objectives were: (i) to determine the number of peer-reviewed publications; (ii) to identify the extent to which the researches focused on diseases identified by the World Health Organization [WHO] State of Health in the African Region Report as being the leading causes of morbidity and mortality in 2018; (iii) to describe the extent and pattern of collaborations between researchers in Africa and the rest of the world; and (iv) to identify leadership and funders of the studies.

METHODOLOGY

We systematically searched Medline via PubMed, Scopus, CINAHL, Academic Search Premier, Africa-Wide Information through EBSCOhost, and Web of Science from inception through to 1st April 2020. We included studies that characterized samples from African populations using next-generation sequencing approaches. Two reviewers independently conducted the literature search, title and abstract, and full-text screening, as well as data extraction.

RESULTS

We included 168 studies out of 5515 records retrieved. Most studies were published in PLoS One (13%; 22/168), and samples were collected from 33 of the 54 African countries. The country where most studies were conducted was South Africa (27/168), followed by Kenya (23/168) and Uganda (18/168). 26.8% (45/168) focused on diseases of significant public health concern in Africa. Collaboration between scientists from the United States of America and Africa was most common (96/168). The first and/or last authors of 79.8% of studies were not affiliated with institutions in Africa. Major funders were the United States of America National Institutes of Health (45.2%; 76/168), Bill and Melinda Gates Foundation (17.8%; 30/168), and the European Union (11.9%; 20/168).

CONCLUSIONS

There are significant gaps in microbiome research in Africa, especially those focusing on diseases of public health importance. There is a need for local leadership, capacity building, intra-continental collaboration, and national government investment in microbiome research within Africa. Video Abstract.

A specific structure and high richness characterize intestinal microbiota of HIV-exposed seronegative individuals

Intestinal microbiota facilitates food breakdown for energy metabolism and influences the immune response, maintaining mucosal homeostasis. Overall, HIV infection is associated with intestinal dysbiosis and immune activation, which has been related to seroconversion in HIV-exposed individuals. However, it is unclear whether microbiota dysbiosis is the cause or the effect of immune alterations and disease progression or if it could modulate the risk of acquiring the HIV infection. We characterize the intestinal microbiota and determine its association with immune regulation in HIV-exposed seronegative individuals (HESN), HIV-infected progressors (HIV+), and healthy control (HC) subjects. For this, feces and blood were collected. The microbiota composition of HESN showed a significantly higher alpha (p = 0.040) and beta diversity (p = 0.006) compared to HC, but no differences were found compared to HIV+. A lower Treg percentage was observed in HESN (1.77%) than HC (2.98%) and HIV+ (4.02%), with enrichment of the genus Butyrivibrio (p = 0.029) being characteristic of this profile. Moreover, we found that Megasphaera (p = 0.017) and Victivallis (p = 0.0029) also are enriched in the microbiota composition in HESN compared to HC and HIV+ subjects. Interestingly, an increase in Succinivibrio and Prevotella, and a reduction in Bacteroides genus, which is typical of HIV-infected individuals, were observed in both HESN and HIV+, compared to HC. Thus, HESNs have a microbiota profile, similar to that observed in HIV+, most likely because HESN are cohabiting with their HIV+ partners.

Different and diverse anaerobic microbiota were seen in women living with HIV with unsuppressed HIV viral load and in women with recurrent bacterial vaginosis: a cohort study

OBJECTIVE

To compare the vaginal microbiota of women living with HIV (WLWH) with the vaginal microbiota of women with recurrent bacterial vaginosis (BV) and healthy women without HIV to determine if there are differences in the vaginal microbiome, what factors influence these differences, and to characterise HIV clinical parameters including viral load and CD4 count in relation to the vaginal microbiome.

DESIGN

Observational cohort study.

SETTING

Canada.

POPULATION

Women aged 18-49 years who were premenopausal and not pregnant were recruited into three cohorts: healthy women, WLWH and women with recurrent BV.

METHODS

Demographic and clinical data were collected via interviews and medical chart reviews. Vaginal swabs were collected for Gram-stain assessment and microbiome profiling using the cpn60 barcode sequence.

MAIN OUTCOME MEASURES

To compare overall community composition differences, we used compositional data analysis methods, hierarchical clustering and Kruskal-Wallis tests where appropriate.

RESULTS

Clinical markers such as odour and abnormal discharge, but not irritation, were associated with higher microbial diversity. WLWH with unsuppressed HIV viral loads were more likely than other groups to have non-Gardnerella-dominated microbiomes. HIV was associated with higher vaginal microbial diversity and this was related to HIV viral load, with unsuppressed women demonstrating significantly higher relative abundance of Megasphaera genomosp. 1, Atopobium vaginae and Clostridiales sp. (all P < 0.05) compared with all other groups.

CONCLUSIONS

In WLWH, unsuppressed HIV viral loads were associated with a distinct dysbiotic profile consisting of very low levels of Lactobacillus and high levels of anaerobes.

TWEETABLE ABSTRACT

Vaginal microbiomes in WLWH with viral load >50 copies/ml have distinct dysbiotic profiles with high levels of anaerobes.

Meta-Analysis of The Prevalence of Genital Infections Among Hiv Carriers and Uninfected Women

Background & Aim:

The risk factors in acquiring genital co-infections associated with HIV infection still present many questions. We conducted a systematic review and meta-analysis to compare the prevalence of genital infection among HIV-infected and uninfected women.

Methods:

We searched PubMed, Web of Science, Scopus and Scielo for the relevant studies up until October 2017. Data were collected from the included studies and methodologically assessed. Odds ratios (OR) and 95% confidence intervals (CI) were pooled using fixed or random-effects models.

Results:

Thirty-six articles involving 23,863 women with retroviruses were included. HIV-infected women were significantly more diagnosed with the following genital infections:Herpes simplexvirus type 2 (HSV-2) (OR 3.70; 95% CI: 2.42–5.65),Neisseria gonorrhoeae(GC) (OR 4.18; 95% CI: 2.15-8.13),Chlamydia trachomatis(CT) (OR 2.25; 95% CI: 1.20-4.23) and Human papillomavirus (HPV) (OR 3.99, 95% CI: 3.35-4.75). There was no significant difference in the prevalence of bacterial vaginosis (OR 1.09; 95% CI: 0.91-1.30),Candida sp. (OR 1.51; 95% CI: 0.71-3.25),Treponema pallidum(OR 1.56; 95% CI: 1.00-2.45) andTrichomonas vaginalis(OR 1.00; 95% CI: 0.47-2.15).

Conclusion:

The prevalence of HPV, HSV-2, GC and CT genital infection was significantly higher among HIV-positive women.

Associations of the vaginal microbiota with HIV infection, bacterial vaginosis, and demographic factors

OBJECTIVE

We sought to investigate the effects of HIV infection on the vaginal microbiota and associations with treatment and demographic factors. We thus compared vaginal microbiome samples from HIV-infected (HIV+) and HIV-uninfected (HIV-) women collected at two Chicago area hospitals.

DESIGN

We studied vaginal microbiome samples from 178 women analyzed longitudinally (n = 324 samples) and collected extensive data on clinical status and demographic factors.

METHODS

We used 16S rRNA gene sequencing to characterize the bacterial lineages present, then UniFrac, Shannon diversity, and other measures to compare community structure with sample metadata.

RESULTS

Differences in microbiota measures were modest in the comparison of HIV+ and HIV- samples, in contrast to several previous studies, consistent with effective antiretroviral therapy. Proportions of healthy Lactobacillus species were not higher in HIV- patients overall, but were significantly higher when analyzed within each hospital in isolation. Rates of bacterial vaginosis were higher among African-American women and HIV+ women. Bacterial vaginosis was associated with higher frequency of HIV+. Unexpectedly, African-American women were more likely to switch bacterial vaginosis status between sampling times; switching was not associated with HIV+ status.

CONCLUSION

The influence of HIV infection on the vaginal microbiome was modest for this cohort of well suppressed urban American women, consistent with effective antiretroviral therapy. HIV+ was found to be associated with bacterial vaginosis. Although bacterial vaginosis has previously been associated with HIV transmission, most of the women studied here became HIV+ many years before our test for bacterial vaginosis, thus implicating additional mechanisms linking HIV infection and bacterial vaginosis.

The Cervicovaginal Microbiota and Its Associations With Human Papillomavirus Detection in HIV-Infected and HIV-Uninfected Women

BACKGROUND

 Bacterial vaginosis (BV) is characterized by low abundance of Lactobacillus species, high pH, and immune cell infiltration and has been associated with an increased risk of human papillomavirus (HPV) infection. We molecularly assessed the cervicovaginal microbiota over time in human immunodeficiency virus (HIV)-infected and HIV-uninfected women to more comprehensively study the HPV-microbiota relationship, controlling for immune status.

METHODS

 16S ribosomal RNA gene amplicon pyrosequencing and HPV DNA testing were conducted annually in serial cervicovaginal lavage specimens obtained over 8-10 years from African American women from Chicago, of whom 22 were HIV uninfected, 22 were HIV infected with a stable CD4⁺ T-cell count of > 500 cells/mm³, and 20 were HIV infected with progressive immunosuppression. Vaginal pH was serially measured.

RESULTS

 The relative abundances of Lactobacillus crispatus and other Lactobacillus species were inversely associated with vaginal pH (all P < .001). High (vs low) L. crispatus relative abundance was associated with decreased HPV detection (odds ratio, 0.48; 95% confidence interval, .24-.96; P_trend = .03) after adjustment for repeated observation and multiple covariates, including pH and study group. However, there were no associations between HPV and the relative abundance of Lactobacillus species as a group, nor with Lactobacillus gasseri, Lactobacillus iners, and Lactobacillus jensenii individually.

CONCLUSIONS

 L. crispatus may have a beneficial effect on the burden of HPV in both HIV-infected and HIV-uninfected women (independent of pH).

Inflammation and HIV Transmission in Sub-Saharan Africa

While the per-contact risk of sexual HIV transmission is relatively low, it is fourfold higher in sub-Saharan Africa, and this may partly explain the major global disparities that exist in HIV prevalence. Genital immune parameters are key determinants of HIV transmission risk, including epithelial integrity and the presence of highly HIV-susceptible intraepithelial or submucosal CD4+ T cell target cells. Biological parameters that may enhance mucosal HIV susceptibility in highly HIV-affected regions of sub-Saharan Africa include increased levels of mucosal inflammation, which can affect both epithelial integrity and target cell availability, as well as the increased mucosal surface area that is afforded by an intact foreskin, contraceptive choices, and intravaginal practices. There are multifactorial causes for increased mucosal inflammation, with the prevalence and nature of common co-infections being particularly relevant.

Metagenomics: A New Way to Illustrate the Crosstalk between Infectious Diseases and Host Microbiome

Microbes have co-evolved with human beings for millions of years. They play a very important role in maintaining the health of the host. With the advancement in next generation sequencing technology, the microbiome profiling in the host can be obtained under different circumstances. This review focuses on the current knowledge of the alteration of complex microbial communities upon the infection of different pathogens, such as human immunodeficiency virus, hepatitis B virus, influenza virus, and Mycobacterium tuberculosis, at different body sites. It is believed that the increased understanding of the correlation between infectious disease and the alteration of the microbiome can contribute to better management of disease progression in the future. However, future studies may need to be more integrative so as to establish the exact causality of diseases by analyzing the correlation between microorganisms within the human host and the pathogenesis of infectious diseases.

Gynecologic health and disease in relation to the microbiome of the female reproductive tract

It is well established that the vagina is colonized by bacteria that serve important roles in homeostasis. Imbalances in the proportion of bacteria may lead to a predisposition to infection or reproductive complications. Molecular-based approaches demonstrated a greater degree of microbial diversity both within and between women than previously recognized. The vaginal microbiome may fluctuate during various states of health, such as during the menstrual cycle or after menopause, and there may be differences in the vaginal microbiome between women of different ethnicities. Furthermore, the specific composition of the vaginal microbiome may influence the predisposition to dysbiosis and the transmission of sexually transmitted infections. An understanding of the diversity of the vaginal microbial environment during states of health is essential for the identification of risk factors for disease and the development of appropriate treatment.

Making inroads into improving treatment of bacterial vaginosis - striving for long-term cure

Bacterial vaginosis (BV) is one of the great enigmas in women's health, a common condition of unknown aetiology, which is associated with significant morbidity and unacceptably high recurrence rates. While it remains unclear whether BV recurrence is predominantly due to failure of current antibiotic regimens to eradicate BV-associated bacteria (BVAB) and biofilm, a failure of some women to re-establish a resilient Lactobacillus-dominant vaginal microbiota, reinfection from sexual partners, or a combination of these factors, it is inherently challenging to make significant inroads towards this goal. In this review, we will outline why BV is such a clinical and epidemiologic conundrum, and focus on several key approaches that we believe merit discussion and clinical research, including strategies to: i) prevent reinfection (partner treatment trials), ii) boost favourable vaginal Lactobacillus species and promote a Lactobacillus-dominant vaginal microbiome (hormonal contraceptive and probiotic trials) and iii) disrupt vaginal BV-associated biofilm.

Robust vaginal colonization of macaques with a novel vaginally disintegrating tablet containing a live biotherapeutic product to prevent HIV infection in women

MucoCept is a biotherapeutic for prevention of HIV-1 infection in women and contains a human, vaginal Lactobacillus jensenii that has been genetically enhanced to express the HIV-1 entry inhibitor, modified cyanovirin-N (mCV-N). The objective of this study was to develop a solid vaginal dosage form that supports sustained vaginal colonization of the MucoCept Lactobacillus at levels previously shown, with freshly prepared cultures, to protect macaques from SHIV infection and to test this formulation in a macaque vaginal colonization model. Vaginally disintegrating tablets were prepared by lyophilizing the formulated bacteria in tablet-shaped molds, then packaging in foil pouches with desiccant. Disintegration time, potency and stability of the tablets were assessed. For colonization, non-synchronized macaques were dosed vaginally with either one tablet or five tablets delivered over five days. Vaginal samples were obtained at three, 14, and 21 days post-dosing and cultured to determine Lactobacillus colonization levels. To confirm identity of the MucoCept Lactobacillus strain, genomic DNA was extracted from samples on days 14 and 21 and a strain-specific PCR was performed. Supernatants from bacteria were tested for the presence of the mCV-N protein by Western blot. The tablets were easy to handle, disintegrated within two minutes, potent (5.7x10¹¹ CFU/g), and stable at 4°C and 25°C. Vaginal administration of the tablets to macaques resulted in colonization of the MucoCept Lactobacillus in 66% of macaques at 14 days post-dosing and 83% after 21 days. There was no significant difference in colonization levels for the one or five tablet dosing regimens (p=0.88 Day 14, p=0.99 Day 21). Strain-specific PCR confirmed the presence of the bacteria even in culture-negative macaques. Finally, the presence of mCV-N protein was confirmed by Western blot analysis using a specific anti-mCV-N antibody.

The significance of Lactobacillus crispatus and L. vaginalis for vaginal health and the negative effect of recent sex: a cross-sectional descriptive study across groups of African women

BACKGROUND

Women in sub-Saharan Africa are vulnerable to acquiring HIV infection and reproductive tract infections. Bacterial vaginosis (BV), a disruption of the vaginal microbiota, has been shown to be strongly associated with HIV infection. Risk factors related to potentially protective or harmful microbiota species are not known.

METHODS

We present cross-sectional quantitative polymerase chain reaction data of the Lactobacillus genus, five Lactobacillus species, and three BV-related bacteria (Gardnerella vaginalis, Atopobium vaginae, and Prevotella bivia) together with Escherichia coli and Candida albicans in 426 African women across different groups at risk for HIV. We selected a reference group of adult HIV-negative women at average risk for HIV acquisition and compared species variations in subgroups of adolescents, HIV-negative pregnant women, women engaging in traditional vaginal practices, sex workers and a group of HIV-positive women on combination antiretroviral therapy. We explored the associations between presence and quantity of the bacteria with BV by Nugent score, in relation to several factors of known or theoretical importance.

RESULTS

The presence of species across Kenyan, South African and Rwandan women was remarkably similar and few differences were seen between the two groups of reference women in Kenya and South Africa. The Rwandan sex workers and HIV-positive women had the highest G. vaginalis presence (p = 0.006). Pregnant women had a higher Lactobacillus genus mean log (7.01 genome equivalents (geq)/ml) compared to the reference women (6.08 geq/ml). L. vaginalis (43%) was second to L. iners (81.9%) highly present in women with a normal Nugent score. Recent sexual exposure negatively affected the presence of L. crispatus (<0.001), L. vaginalis (p = 0.001), and Lactobacillus genus (p < 0.001). Having more than one sexual partner in the last three months was associated with an increased prevalence of G. vaginalis (p = 0.044) and L. iners (p = 0.001).

CONCLUSIONS

Although the composition of species across the studied African countries was similar, the presence of protective species i.e. L. crispatus and L. vaginalis in women with a normal Nugent score appeared lower compared to non-African studies. Furthermore, Lactobacillus species were negatively affected by sexual behavioural. Strategies to support protective Lactobacillus species are urgently needed.

TRIAL REGISTRATION

The study is registered at the Trial Registration at the National Health Research Ethics Council South Africa with the number DOH2709103223.