BACKGROUND:Congenital syphilis (CS) remains a major cause of stillbirth and neonatal morbidity, with an estimated 700,000 cases and 390,000 adverse birth outcomes annually. We evaluated the diagnostic utility of combined treponemal (TT) and nontreponemal (NTT) rapid point-of-care test and Treponema pallidum polymerase chain reaction (PCR) for detecting active maternal syphilis, CS, and treatment response in a high-prevalence, low-resource setting. METHODS:Secondary analyses were conducted from a prospective case-control study at Queen Elizabeth Central Hospital, Malawi. Women were recruited ≤48 h postpartum. Maternal and infant sera underwent testing with the DPP® Syphilis Screen and Confirm (Dual rapid diagnostic test [RDT]) and T. pallidum PCR (maternal vaginal swabs and infant nasopharyngeal swabs), with predefined clinical-serological reference standards based on qualitative rapid plasma reagin (RPR). RESULTS:Among 504 of 510 women with complete data, Dual RDT identified 110 seropositive cases at delivery, including 86 new maternal syphilis diagnoses. The NTT band showed good performance in mothers versus RPR (sensitivity: 84.8% [95% confidence interval: 77.4%-92.1%]; specificity 92.7% [95% confidence interval: 90.3%-95.1%]) but reduced sensitivity in infants, increasing from 51.9% to 80.0% with RPR titer. Laboratory visual and microreader interpretation showed high concordance (99.5%), while bedside visual accuracy was lower (77.4%). Any Dual RDT positivity identified 19 high-risk infants, of whom 7 of 19 (36.8%) were NTT positive. PCR detected maternal infection in 11 of 504 (2.2%), including 3 serology-negative cases. CONCLUSIONS:Dual RDT improves detection over TT alone. The NTT band without quantitation is insufficient for treatment monitoring or infant diagnosis. Combining Dual RDT with PCR may enhance detection of active maternal infection and CS in high-burden settings.

BACKGROUND:There are limited data on the epidemiology of sexually transmitted infections (STI) and their contribution to adverse birth outcomes (ABO) in sub-Saharan Africa (SSA). We performed a case-control study to assess the prevalence of STI and their association with ABO among women attending Queen Elizabeth Central Hospital, Blantyre, Malawi. METHODS:A composite case definition for ABO included stillborn, preterm and low birthweight infants and infants admitted to neonatal intensive care unit within 24 hours of birth. Following recruitment of an infant with an ABO, the next born healthy infant was recruited as a control. Multiplex PCR for Neisseria gonorrhoeae (NG), Chlamydia trachomatis (CT) and Trichomonas vaginalis (TV) was performed on maternal vaginal swabs. HIV and syphilis status was determined on maternal and infant serum. For syphilis, we used combined treponemal/non-treponemal rapid point-of-care tests in parallel with rapid plasma reagin tests, PCR for Treponema pallidum and clinical parameters to diagnose and stage the infection. We compared STI positivity between cases and controls. RESULTS:We included 259 cases and 251 controls. Maternal prevalence of STI was 3.1%, 2.7% and 17.1% for NG, CT and TV, respectively. Maternal prevalence of untreated syphilis was 2.0% and 6.1% for early stage and late/unknown stage, respectively; prevalence of treated syphilis was 2.7%. The HIV prevalence was 16.5%. HIV infection significantly increased the odds for ABO (OR=3.31; 95% CI 1.10 to 9.91) as did NG positivity (OR=4.30; 95% CI 1.16 to 15.99). We observed higher rates of ABO among women with untreated maternal syphilis (early: OR=7.13; 95% CI 0.87 to 58.39, late/unknown stage: OR=1.43; 95% CI 0.65 to 3.15). Maternal TV and CT infections were not associated with ABO. CONCLUSION:STI prevalence among pregnant women in Malawi is comparable to other SSA countries. HIV, NG and untreated syphilis prevalence was higher among women with ABO compared with women with healthy infants.

Background: Over two-thirds of global maternal deaths occur in Sub-Saharan Africa (SSA), with more than 200,000 deaths per year. Maternal sepsis causes 10% of these deaths, twice the proportion observed in high-income countries. In SSA, limited access to diagnostic microbiology facilities poses difficulties in promptly identifying and managing maternal infection and sepsis. This protocol describes a systematic review and meta-analysis that aims to summarize available data on the main bacterial agents causing maternal infections and their antibiotic susceptibility in SSA. Methods: Three electronic databases will be searched: MEDLINE, Embase and African Journals Online. Our search strategy will combine terms relating to laboratory-confirmed bacterial infection, pregnancy, postnatal period and SSA. We will include observational studies describing maternal bacterial infection's aetiology and antimicrobial resistance patterns in SSA. Two authors will perform study selection, data extraction and quality assessment. A third author will be consulted to resolve disagreements if they arise.We will summarize the proportion (and 95% confidence intervals) of samples testing positive for the most common bacteria and, depending on the data's availability and heterogeneity, examine results by country and/or region. If possible, we will describe trends over time and differentiate aetiological organisms and resistance/sensitivities by maternal infection sources. We will also undertake subgroup analyses based on HIV status, the invasive and non-invasive status of the infection, SSA sub-regions and mortality if there is adequate information to make such subgroup analysis feasible. Discussion: Data on the microbiologic outcomes for maternal infections in SSA are likely fragmented and not fully representative due to the limited availability of microbiology diagnostics and geographical differences in clinical and laboratory practices. If this is the case, policies and programme strategies to guide treatment and identify antimicrobial resistance threats in SSA settings will be challenging to target. Our systematic review aims to provide a comprehensive summary of the available data, describe the main organisms causing maternal infection and their sensitivities, and identify areas that require further research. Prospero ID: CRD42021238515

Background Compared to the abundance of clinical and genomic information available on patients hospitalised with COVID-19 disease from high-income countries, there is a paucity of data from low-income countries. Our aim was to explore the relationship between viral lineage and patient outcome. Methods We enrolled a prospective observational cohort of adult patients hospitalised with PCR-confirmed COVID-19 disease between July 2020 and March 2022 from Blantyre, Malawi, covering four waves of SARS-CoV-2 infections. Clinical and diagnostic data were collected using an adapted ISARIC clinical characterization protocol for COVID-19. SARS-CoV-2 isolates were sequenced using the MinION™ in Blantyre. Results We enrolled 314 patients, good quality sequencing data was available for 55 patients. The sequencing data showed that 8 of 11 participants recruited in wave one had B.1 infections, 6/6 in wave two had Beta, 25/26 in wave three had Delta and 11/12 in wave four had Omicron. Patients infected during the Delta and Omicron waves reported fewer underlying chronic conditions and a shorter time to presentation. Significantly fewer patients required oxygen (22.7% [17/75] vs. 58.6% [140/239], p < 0.001) and steroids (38.7% [29/75] vs. 70.3% [167/239], p < 0.001) in the Omicron wave compared with the other waves. Multivariable logistic-regression demonstrated a trend toward increased mortality in the Delta wave (OR 4.99 [95% CI 1.0–25.0 p = 0.05) compared to the first wave of infection. Conclusions Our data show that each wave of patients hospitalised with SARS-CoV-2 was infected with a distinct viral variant. The clinical data suggests that patients with severe COVID-19 disease were more likely to die during the Delta wave.

Background There is a high prevalence of infections and sepsis in pregnancy in Malawi, with evidence of a rising incidence of antimicrobial resistance. Lack of resources to inform the organism-specific therapy of maternal infections results in a significant proportion of maternal deaths being due to infections and sepsis. Through the implementation of a microbiology services for obstetrics patients, we aimed to describe the epidemiology and antimicrobial resistance profile of maternal infections in a tertiary hospital in Blantyre, Malawi, and investigate the impact of maternal infections surveillance platform on pregnancy outcomes. Methods Data on pregnant women from a maternal infections surveillance project serving a tertiary hospital in Blantyre, Malawi from 1 February 2021 to 30 March 2023 was used for the analysis. Descriptive statistics were used to describe the prevalence of infection and antimicrobial resistance. The association between infection from different samples and adverse delivery outcomes (a composite created through theory-driven grouping of a priori defined variables) was tested using multivariate logistics regression. Results Preliminary analysis on urine sample data for 347 patients shows the prevalence of infections in urine in this population was 41.2% (95% CI of 36.0% to 46.4%), with up to two-thirds (57.3%) of the patients being on at least one empirical antibiotic on admission. 29.2% of the cultures grew Escherichia coli, and 8.2% grew Klebsiella pneumoniae. There were high levels of antimicrobial resistance demonstrated by the commonest isolates, especially Pseudomonas aeruginosa. Infection in urine was associated with adverse delivery outcomes 1.95 (95% CI 1.24 to 3.10, p=0.004). Having a culture result significantly informed the choice of antibiotic prescribed to a patient. Conclusion These results suggest that having an infection in urine is associated with a greater prevalence of adverse delivery outcomes. Additional studies of a prospective nature are required to rigorously investigate this association.

Background Compared to the abundance of clinical, molecular, and genomic information available on patients hospitalised with COVID-19 disease from high-income countries, there is a paucity of data from low-income countries. Methods We enrolled a cohort of patients with PCR confirmed COVID-19 disease at Queen Elizabeth Central Hospital, the main hospital for southern Malawi, between July 2020 and September 2021. The recruitment period covered three waves of SARS-CoV-2 infections in Malawi. Clinical and diagnostic data were collected using the ISARIC clinical characterization protocol for COVID-19. The viral material from PCR-positive swabs was amplified with a tiling PCR scheme and sequenced using the MinION sequencer in Malawi. Consensus genomes were generated using the ARTIC pipeline and lineage assignment was performed using Pangolin. Results Sequencing data showed that wave one was predominantly B.1 (8/11 samples), wave two consisted entirely of Beta variant of concern (VOC) (6/6), and wave three was predominantly Delta VOC (25/26). Patients presenting in the second and third waves had progressively fewer underlying chronic conditions, and patients in the third wave had a shorter time to presentation (2 days vs 5 in the original wave). Multivariable logistic regression demonstrated increased mortality in wave three, dominated by the Delta VOC, compared to previous waves (OR 6.6 [CI 1.1-38.8]). Conclusions Patients hospitalised with COVID-19 in Blantyre during the Delta wave had more acute symptom onset; fewer underlying conditions; and were more likely to die. Whilst we demonstrate the value of linking virus sequence data with clinical outcome data in a low-income setting, this study also highlights the considerable barriers to establishing sequencing capacity in a setting heavily affected by disruptions in supply chain and inequity of resource distribution.

Postmenopausal women and renal transplant recipients are at increased risk of recurrent urinary tract infections (RUTI). Urine and vaginal microbiota of premenopausal controls (N = 18) and RUTI cases (18), and of postmenopausal controls (30) and RUTI cases (20) with and without a renal transplant, were characterized using 16S rRNA sequencing. Participants did not have UTI symptoms at the time of sampling. Gram-negative uropathobionts (predominantly Escherichia/Shigella, Pseudomonas, Klebsiella, and Acinetobacter) had a much higher mean relative abundance in urine than vaginal samples, especially in premenopausal women. No statistically significant differences in mean relative abundances of bacterial groups were found within the premenopausal group or within the postmenopausal group by RUTI or renal transplant status without chronic antibiotic use. Comparing postmenopausal to premenopausal women, mean relative abundances of lactobacilli (especially L. crispatus) in urine and vaginal samples and of Gram-negative uropathobionts in urine were lower, and of BV-anaerobes and Gram-positive uropathobionts in urine and vaginal samples were higher. While RUTI in premenopausal women is predominantly caused by Escherichia, the causative organisms in postmenopausal women are likely more diverse. The relative importance of individual organisms is currently unknown. We recommend that future studies, including intervention studies, include longitudinal microbiota assessments.

Immunoglobulin A (IgA) plays an important role in maintaining a healthy intestinal microbiome, but little is known about the interaction between local immunoglobulins and the vaginal microbiome. We assessed immunoglobulins (unbound and bound to bacteria), their association with vaginal microbiota composition and the changes over time in 25 healthy women of reproductive age. In both Lactobacillus crispatus-dominated and non-L. crispatus-dominated microbiota, IgA and IgG (unbound and bound to bacteria) were higher during menses (T = 1) compared to day 7‑11 (T = 2) and day 17‑25 (T = 3) after menses onset. The majority of vaginal bacteria are coated with IgA and/or IgG. Women with L. crispatus-dominated microbiota have increased IgA coating of vaginal bacteria compared to women with other microbiota compositions, but contained less IgA per bacterium. Presence of a dominantly IgA-coated population at T = 2 and/or T = 3 was also strongly associated with L. crispatus-dominated microbiota. In women with non-L. crispatus-dominated microbiota, more bacteria were uncoated. Unbound IgA, unbound IgG, and bound IgG levels were not associated with microbiota composition. In conclusion, L. crispatus-dominated vaginal microbiota have higher levels of bacterial IgA coating compared to non-L. crispatus-dominated vaginal microbiota. Similar to its regulating function in the intestinal tract, we hypothesize that IgA is involved in maintaining L. crispatus-dominated microbiota in the female genital tract. This may play a role in L. crispatus-associated health benefits.

Although the COVID-19 pandemic has left no country untouched there has been limited research to understand clinical and immunological responses in African populations. Here we characterise patients hospitalised with suspected (PCR-negative/IgG-positive) or confirmed (PCR-positive) COVID-19, and healthy community controls (PCR-negative/IgG-negative). PCR-positive COVID-19 participants were more likely to receive dexamethasone and a beta-lactam antibiotic, and survive to hospital discharge than PCR-negative/IgG-positive and PCR-negative/IgG-negative participants. PCR-negative/IgG-positive participants exhibited a nasal and systemic cytokine signature analogous to PCR-positive COVID-19 participants, predominated by chemokines and neutrophils and distinct from PCR-negative/IgG-negative participants. PCR-negative/IgG-positive participants had increased propensity for Staphylococcus aureus and Streptococcus pneumoniae colonisation. PCR-negative/IgG-positive individuals with high COVID-19 clinical suspicion had inflammatory profiles analogous to PCR-confirmed disease and potentially represent a target population for COVID-19 treatment strategies.

Lactobacillus crispatus is the dominant species in the vagina of many women. With the potential for strains of this species to be used as a probiotic to help prevent and treat dysbiosis, we investigated isolates from vaginal swabs with Lactobacillus-dominated and a dysbiotic microbiota. A comparative genome analysis led to the identification of metabolic pathways for synthesis and degradation of three major biogenic amines in most strains. However, targeted metabolomic analysis of the production and degradation of biogenic amines showed that certain strains have either the ability to produce or to degrade these compounds. Notably, six strains produced cadaverine, one produced putrescine, and two produced tyramine. These biogenic amines are known to raise vaginal pH, cause malodour, and make the environment more favourable to vaginal pathogens. In vitro experiments confirmed that strains isolated from women with a dysbiotic vaginal microbiota have higher antimicrobial effects against the common urogenital pathogens Escherichia coli and Enterococcus faecium. The results indicate that not all L. crispatus vaginal strains appear suitable for probiotic application and the basis for selection should not be only the overall composition of the vaginal microbiota of the host from which they came, but specific biochemical and genetic traits.

Vaginal malodour is a sign of dysbiosis. The biogenic amines (BAs) cadaverine, putrescine and tyramine are known to be causative compounds. Recent reports suggest these compounds produced by pathogens might have a role beyond causing malodour; namely inhibiting the growth of lactobacilli bacteria that are crucial in the maintenance of vaginal homeostasis. The aim of this study was to identify whether certain lactobacilli strains could reduce BAs and to evaluate how Lactobacillus species were affected by these compounds. Using LC-MS and HPLC-UV, five Lactobacillus crispatus strains were identified as being capable of significantly reducing BAs from the media under in vitro conditions. Through 16S rRNA gene sequencing of vaginal swabs exposed to Bas, cadaverine was found to reduce the relative abundance of lactobacilli. When L. crispatus was exposed to media supplemented with BAs with an HCl adjusted lower pH, its growth was enhanced, demonstrating the relevance of the maintenance of an acidic vaginal environment. If strains are to be developed for probiotic application to alleviate bacterial vaginosis and other conditions affecting large numbers of women worldwide, their ability to adapt to Bas and regulate pH should be part of the experimentation.

Understanding the host viral interaction at the nasal mucosa, the primary site of SARSCoV2 infection, may provide important insights into COVID19 pathogenesis. Here, we studied nasal and systemic immune parameters in comprehensively characterised patients hospitalised with suspected or confirmed COVID19, and healthy community controls. PCR confirmed COVID19 participants were more likely to receive dexamethasone and a betalactam antibiotic, and more likely to survive to hospital discharge than PCR negative/IgG+ and PCR negative/IgG- participants. PCR negative/IgG+ participants exhibited a nasal and systemic cytokine signature analogous to PCR confirmed COVID19 participants, but had an increased propensity for Staphylococcus aureus and Streptococcus pneumoniae colonisation. The nasal immune signature in PCR negative/IgG+ and PCR confirmed COVID19 participants was distinct and predominated by chemokines and neutrophils. These findings demonstrate that severe COVID19 is associated with inflammatory chemokine and neutrophil predominance in the nasal mucosa, and that PCR negative/IgG+ individuals with high COVID19 clinical suspicion have inflammatory profiles analogous to PCR confirmed disease.

Sequencing studies have shown that optimal vaginal microbiota (VMB) are lactobacilli-dominated and that anaerobes associated with bacterial vaginosis (BV-anaerobes) are commonly present. However, they overlooked a less prevalent but more pathogenic group of vaginal bacteria: the pathobionts that cause maternal and neonatal infections and pelvic inflammatory disease. We conducted an individual participant data meta-analysis of three VMB sequencing studies that included diverse groups of women in Rwanda, South Africa, and the Netherlands (2,044 samples from 1,163 women in total). We identified 40 pathobiont taxa but only six were non-minority taxa (at least 1% relative abundance in at least one sample) in all studies: Streptococcus (54% of pathobionts reads), Staphylococcus, Enterococcus, Escherichia/Shigella, Haemophilus, and Campylobacter. When all pathobionts were combined into one bacterial group, the VMB of 17% of women contained a relative abundance of at least 1%. We found a significant negative correlation between relative abundances (ρ = −0.9234), but not estimated concentrations (r = 0.0031), of lactobacilli and BV-anaerobes; and a significant positive correlation between estimated concentrations of pathobionts and BV-anaerobes (r = 0.1938) but not between pathobionts and lactobacilli (r = 0.0436; although lactobacilli declined non-significantly with increasing pathobionts proportions). VMB sequencing data were also classified into mutually exclusive VMB types. The overall mean bacterial load of the ≥20% pathobionts VMB type (5.85 log10 cells/μl) was similar to those of the three lactobacilli-dominated VMB types (means 5.13–5.83 log10 cells/μl) but lower than those of the four anaerobic dysbiosis VMB types (means 6.11–6.87 log10 cells/μl). These results suggest that pathobionts co-occur with both lactobacilli and BV-anaerobes and do not expand as much as BV-anaerobes do in a dysbiotic situation. Pathobionts detection/levels were increased in samples with a Nugent score of 4–6 in both studies that conducted Nugent-scoring. Having pathobionts was positively associated with young age, non-Dutch origin, hormonal contraceptive use, smoking, antibiotic use in the 14 days prior to sampling, HIV status, and the presence of sexually transmitted pathogens, in at least one but not all studies; inconsistently associated with sexual risk-taking and unusual vaginal discharge reporting; and not associated with vaginal yeasts detection by microscopy. We recommend that future VMB studies quantify common vaginal pathobiont genera.

Objective Vaginal steam baths with herb leaves (herb use) is practised by some Surinamese women. We assessed herb use among women from the five most prevalent ethnic groups, and if herb use is associated with Chlamydia trachomatis infection. Setting Participants were recruited at a sexually transmitted infection (STI) clinic and a family planning clinic (FP) in Paramaribo, Suriname. Participants 1040 women were included subsequently, comprising the following ethnic groups: Creole (26.7%), Hindustani (24.6%), Javanese (15.7%), Maroon (13.3%) and mixed descent (19.7%). Methods Nurses collected a questionnaire and vaginal swabs for nucleic acid amplification C. trachomatis testing. Primary outcomes Determinants of vaginal herb use and C. trachomatis infection via univariable and multivariable logistic regression. Results Herb use was most common among Maroon (68.8%) and Creole women (25.2%). In multivariable analysis including only Maroon and Creole women, determinants significantly associated with vaginal herb use were (OR; 95% CI): Maroon ethnic descent (5.33; 3.26 to 8.71 vs Creole), recruitment at the STI clinic (2.04; 1.24 to 3.36 vs FP), lower education levels (3.80; 1.68 to 8.57 lower vs higher, and 2.02; 0.90 to 4.51 middle vs higher). Lower age and recruitment at the STI clinic were associated with C. trachomatis infection, but not vaginal herb use. Conclusion In Suriname, vaginal herb use is common among Maroon and Creole women. Education, ethnic group and recruitment site were determinants for herb use. Vaginal herb use was not a determinant of C. trachomatis infection. Future research should focus on the effect of herb use on the vaginal microbiome and mucosal barrier.

Over-the-counter intra-vaginal lactic-acid containing douches are marketed as vaginal hygiene products that support optimal vaginal pH balance. We report the effect of a commercially available douche (Etos®) on the vaginal microbiota (VM) in a prospective study. Twenty-five healthy women were recruited through advertisements in 2015–2017 (ethical approval: METC-2014_413) and followed over three menstrual cycles. The participants had a median age of 24 years [IQR: 22–29], were mostly Dutch-Caucasian (88%), and 60% used combined oral contraceptives. All participants douched three times a week during the second cycle, starting on the first day of that cycle. Participants completed a questionnaire at baseline, kept a daily diary to report douching, menses, and sexual activity, self-collected vaginal swabs every other day during the first and third cycle and daily during the second cycle, and measured vaginal pH mid-cycle. A median of 44 vaginal swabs [inter-quartile range (IQR): 41–50] were assessed per participant by 16S rRNA gene (V3-V4 region) sequencing and a Candida albicans PCR was done at four time-points. At baseline, 21 participants (84%) had Lactobacillus-dominated VM (Lactobacillus crispatus (n = 14), L. iners (n = 6), or diverse Lactobacillus species (n = 1) and 4 participants (16%) had VM consisting of diverse anaerobes. In multinomial logistic regression models, a trend towards increased odds were observed for having diverse anaerobic VM in the second and third cycle, compared to the first cycle, after adjusting for menses [odds ratio (OR) = 1.4 (95% CI: 0.9–2.1) and OR = 1.7 (95% CI: 0.9–3.1), respectively] (p = 0.376). Douching did not affect vaginal pH. Menses increased the odds for having VM consisting of diverse anaerobes almost two-fold (OR = 1.7; 95% CI: 1.0–2.8), while douching during menses increased the odds 2.6 fold (OR = 2.6; 95% CI: 1.0–6.5), compared to not menstruating (p = 0.099). Participants were more likely to test positive for C. albicans after cycle 2, compared to cycle 1 [OR = 3.0 (95% CI: 1.2–7.2); p = 0.017]. The Etos® douche did not significantly affect the vaginal pH or VM composition, although increased odds for having diverse anaerobic VM was observed, especially when douching during menses. Furthermore, douching may promote C. albicans infections.

Increasing evidence suggests that the composition of the vaginal microbiota (VM) affects a woman’s sexual and reproductive wellbeing. Lactobacillus-dominated VM is associated with vaginal health (pH<4.5, no inflammation), whereas a VM consisting of diverse anaerobes (i.e. vaginal dysbiosis) increases a woman’s susceptibility to sexually transmitted infections (STI) and adverse pregnancy outcomes. This thesis covers topics relating to biological and (modifiable) behavioral factors that may associate with VM composition and also explores the use of molecular tools to assess the epidemiology of common vaginal conditions such as bacterial vaginosis and trichomoniasis. Embedded in a larger Amsterdam population-based study, we found that women of African descent were more likely to have vaginal dysbiosis than Dutch-Caucasian women, independent of modifiable behavioral factors. In a separate longitudinal study among Dutch healthy women we found that vaginal douching increased the odds for having vaginal dysbiosis, but not statistically significantly so. In women notified for Chlamydia trachomatis infection by a sex partner, we found that women with vaginal dysbiosis were four times more likely to test positive for infection than women with Lactobacillus crispatus-dominated VM. Lactobacillus crispatus could potentially be used as a probiotic to restore vaginal dysbiosis and our comparative genomic analysis of 30 human isolates revealed bacterial genes relating to this species’ adaptation to the vaginal niche. Molecular tools are sensitive methods to diagnose bacterial vaginosis however the high prevalence of asymptomatic vaginal dysbiosis limits their specificity. Molecular typing of T. vaginalis demonstrated a two-genotype population structure, where genotype I was more likely to be infected with a virus, which subsequently associated with reporting urogenital symptoms by the patient. T. vaginalis infections positively associated with age and infections were rare among men in the Netherlands.

A vaginal microbiota dominated by lactobacilli (particularly Lactobacillus crispatus) is associated with vaginal health, whereas a vaginal microbiota not dominated by lactobacilli is considered dysbiotic. Here we investigated whether L. crispatus strains isolated from the vaginal tract of women with Lactobacillus-dominated vaginal microbiota (LVM) are pheno- or genotypically distinct from L. crispatus strains isolated from vaginal samples with dysbiotic vaginal microbiota (DVM). We studied 33 L. crispatus strains (n = 16 from LVM; n = 17 from DVM). Comparison of these two groups of strains showed that, although strain differences existed, both groups degraded various carbohydrates, produced similar amounts of organic acids, inhibited Neisseria gonorrhoeae growth, and did not produce biofilms. Comparative genomics analyses of 28 strains (n = 12 LVM; n = 16 DVM) revealed a novel, 3-fragmented glycosyltransferase gene that was more prevalent among strains isolated from DVM. Most L. crispatus strains showed growth on glycogen-supplemented growth media. Strains that showed less-efficient (n = 6) or no (n = 1) growth on glycogen all carried N-terminal deletions (respectively, 29 and 37 amino acid deletions) in a putative pullulanase type I protein. L. crispatus strains isolated from LVM were not phenotypically distinct from L. crispatus strains isolated from DVM; however, the finding that the latter were more likely to carry a 3-fragmented glycosyltransferase gene may indicate a role for cell surface glycoconjugates, which may shape vaginal microbiota-host interactions. Furthermore, the observation that variation in the pullulanase type I gene is associated with growth on glycogen discourages previous claims that L. crispatus cannot directly utilize glycogen.

Comparative genomics of human Lactobacillus crispatus isolates reveals genes for glycosylation and 1 glycogen degradation: Implications for in vivo dominance of the vaginal microbiota. 2 3 Charlotte van der Veer 1 , Rosanne Y. Hertzberger 2 , Sylvia M. Bruisten 1,7 , Hanne L.P. Tytgat 3 , Jorne 4 Swanenburg, Alie de Kat Angelino-Bart, Frank Schuren, Douwe Molenaar, Gregor Reid, Henry de 5 Vries 1,7 , and Remco Kort 2,4 * 6 7 Affiliations: 8

ABSTRACTPerturbations to the vaginal microbiota can lead to dysbiosis, including bacterial vaginosis (BV), which affects a large portion of the female population. In a healthy state, the vaginal microbiota is characterized by low diversity and colonization byLactobacillusspp., whereas in BV, these species are displaced by a highly diverse population of bacteria associated with adverse vaginal health outcomes. Since prebiotic ingestion has been a highly effective approach to invigorate lactobacilli for improved intestinal health, we hypothesized that these compounds could stimulate lactobacilli at the expense of BV organisms to maintain vaginal health. Monocultures of commensalLactobacillus crispatus,Lactobacillus vaginalis,Lactobacillus gasseri,Lactobacillus johnsonii,Lactobacillus jensenii, andLactobacillus iners, in addition to BV-associated organisms andCandida albicans, were tested for their ability to utilize a representative group of prebiotics consisting of lactitol, lactulose, raffinose, and oligofructose. The disaccharide lactulose was found to most broadly and specifically stimulate vaginal lactobacilli, including the strongly health-associated speciesL. crispatus, and importantly, not to stimulate BV organisms orC. albicans. Using freshly collected vaginal samples, we showed that exposure to lactulose promoted commensalLactobacillusgrowth and dominance and resulted in healthy acidity partially through lactic acid production. This provides support for further testing of lactulose to prevent dysbiosis and potentially to reduce the need for antimicrobial agents in managing vaginal health.IMPORTANCEBacterial vaginosis (BV) and other dysbioses of the vaginal microbiota significantly affect the quality of life of millions of women. Antimicrobial therapy is often poorly effective, causes side effects, and does not prevent recurrences. We report one of very few studies that have evaluated how prebiotics—compounds that are selectively fermented by beneficial bacteria such asLactobacillusspp.—can modulate the vaginal microbiota. We also report use of a novelin vitropolymicrobial model to study the impact of prebiotics on the vaginal microbiota. The identification of prebiotic lactulose as enhancingLactobacillusgrowth but not that of BV organisms orCandida albicanshas direct application for retention of homeostasis and prevention of vaginal dysbiosis and infection.

Purpose. Bacterial vaginosis (BV) is a common clinical condition characterized by odorous vaginal discharge, vaginal itching and/or burning. BV can occur when vaginal lactobacilli are depleted and replaced by diverse anaerobic bacteria. We evaluated a commercial multiplex PCR (ATRiDA) for the diagnosis of BV. Methods. Cervicovaginal samples were included from women reporting urogenital symptoms and from women notified for sexually transmitted infections (STI) – who were not (necessarily) symptomatic. Clinical BV diagnoses were obtained from electronic patient files. The ATRiDA test measures the loads of Gardnerella vaginalis, Atopobium vaginae and Lactobacillus species in relation to overall bacterial load. The ATRiDA test outcome was compared to the clinical BV diagnosis and to vaginal microbiota composition, determined by 16SrRNA gene sequencing. Results. We included samples from 185 women reporting urogenital symptoms, of whom 81 had BV and 93 women who were notified for an STI, of whom 16 had BV. Overall, compared to the clinical BV diagnosis, the ATRiDA test demonstrated high sensitivity (96.9 %) and moderate specificity (70.2 %). The negative predictive value was high (>97.3). The positive predictive value differed by study group and was highest in women reporting urogenital symptoms (78.2 %). Sequencing showed that 54 % of women who had an ATRiDA BV-positive test outcome, but who were not clinically diagnosed with BV, had diverse anaerobic vaginal microbiota (asymptomatic vaginal dysbiosis). Conclusion. The ATRiDA test is a sensitive method for the detection of BV but, given the high occurrence of asymptomatic vaginal dysbiosis, a positive test outcome should be interpreted together with clinical symptoms.