The Relationship Between Insertive Oral and Anal Sex and Select Measures of the Composition of the Urethral Microbiota Among Men Who Have Sex With Men

BACKGROUND

Sexual behavior may influence the composition of the male urethral microbiota, but this hypothesis has not been tested in longitudinal studies of men who have sex with men (MSM).

METHODS

From December 2014 to July 2018, we enrolled MSM with nongonococcal urethritis (NGU) attending a sexual health clinic. Men attended 5 in-clinic visits at 3-week intervals, collected weekly urine specimens at home, and reported daily antibiotics and sexual activity on weekly diaries. We applied broad-range 16S rRNA gene sequencing to urine. We used generalized estimating equations to estimate the association between urethral sexual exposures in the prior 7 days (insertive oral sex [IOS] only, condomless insertive anal intercourse [CIAI] only, IOS with CIAI [IOS + CIAI], or none) and Shannon index, number of species (observed, oral indicator, and rectal indicator), and specific taxa, adjusting for recent antibiotics, age, race/ethnicity, HIV, and preexposure prophylaxis.

RESULTS

Ninety-six of 108 MSM with NGU attended ≥1 follow-up visit. They contributed 1140 person-weeks of behavioral data and 1006 urine specimens. Compared with those with no urethral sexual exposures, those with IOS only had higher Shannon index ( P = 0.03 ) but similar number of species and presence of specific taxa considered, adjusting for confounders; the exception was an association with Haemophilus parainfluenzae . CIAI only was not associated with measured aspects of the urethral microbiota. IOS + CIAI was only associated with presence of H. parainfluenzae and Haemophilus .

CONCLUSIONS

Among MSM after NGU, IOS and CIAI did not seem to have a substantial influence on measured aspects of the composition of the urethral microbiota.

Association between vaginal microbiota and vaginal inflammatory immune markers in postmenopausal women

OBJECTIVE

In premenopausal individuals, vaginal microbiota diversity and lack of Lactobacillus dominance are associated with greater mucosal inflammation, which is linked to a higher risk of cervical dysplasia and infections. It is not known if the association between the vaginal microbiota and inflammation is present after menopause, when the vaginal microbiota is generally higher-diversity and fewer people have Lactobacillus dominance.

METHODS

This is a post hoc analysis of a subset of postmenopausal individuals enrolled in a randomized trial for treatment of moderate-severe vulvovaginal discomfort that compared vaginal moisturizer, estradiol, or placebo. Vaginal fluid samples from 0, 4, and 12 weeks were characterized using 16S rRNA gene sequencing (microbiota) and MesoScale Discovery (vaginal fluid immune markers: IL-1b, IL-1a, IL-2, IL-6, IL-18, IL-10, IL-9, IL-13, IL-8, IP10, MIP1a, MIP1b, MIP3a). Global associations between cytokines and microbiota (assessed by relative abundance of individual taxa and Shannon index for alpha, or community, diversity) were explored, adjusting for treatment arm, using linear mixed models, principal component analysis, and Generalized Linear Mixed Model + Microbiome Regression-based Kernel Association Test (GLMM-MiRKAT).

RESULTS

A total of 119 individuals with mean age of 61 years were included. At baseline, 29.5% of participants had a Lactobacillus-dominant vaginal microbiota. Across all timepoints, alpha diversity (Shannon index, P = 0.003) was highly associated with immune markers. Individual markers that were associated with Lactobacillus dominance were similar to those observed in premenopausal people: IL-10, IL-1b, IL-6, IL-8 (false discovery rate [FDR] < 0.01), IL-13 (FDR = 0.02), and IL-2 (FDR = 0.09). Over 12 weeks, change in alpha diversity was associated with change in cytokine concentration (Shannon, P = 0.018), with decreased proinflammatory cytokine concentrations observed with decreasing alpha diversity.

CONCLUSIONS

In this cohort of postmenopausal individuals, Lactobacillus dominance and lower alpha diversity were associated with lower concentrations of inflammatory immune markers, as has been reported in premenopausal people. This suggests that after menopause lactobacilli continue to have beneficial effects on vaginal immune homeostasis, despite lower prevalence.

Effect of Metronidazole on Concentrations of Vaginal Bacteria Associated with Risk of HIV Acquisition

Several bacterial vaginosis (BV)-associated bacteria have been associated with elevated risk of HIV acquisition, however susceptibility of these bacteria to antibiotics is poorly understood. Vaginal samples were collected from 22 persons daily for two weeks following BV diagnosis. Metronidazole treatment was prescribed for 5-7 days. Changes in bacterial concentrations were measured with taxon-specific 16S rRNA gene quantitative PCR (qPCR) assays. A culture-based antimicrobial assay confirmed presence of antibiotics in vaginal swab samples. Bacterial DNA concentrations decreased during antibiotic administration for all thirteen bacterial taxa tested. Comparison of bacterial DNA concentrations in samples before administration of antibiotics to samples taken on the last day of antimicrobial assay-confirmed antibiotic presence showed a 2.3-4.5 log10-fold decrease across all taxa. Concentrations were frequently reduced to the qPCR assay's limit of detection, suggesting eradication of bacteria. Mean clearance time varied across taxa (1.2-8.6 days), with several bacteria (e.g., Gemella asaccharolytica, Sneathia spp., Eggerthella-like sp.) taking >7 days to suppress. Metronidazole reduces quantities of bacterial taxa associated with increased HIV acquisition risk. Eradication of high-risk vaginal bacteria using metronidazole is one promising avenue for reducing HIV acquisition risk. A 5-7-day treatment course may not be sufficient to suppress all bacteria.

Identification of fallopian tube microbiota and its association with ovarian cancer

Investigating the human fallopian tube (FT) microbiota has significant implications for understanding the pathogenesis of ovarian cancer (OC). In this large prospective study, we collected swabs intraoperatively from the FT and other surgical sites as controls to profile the microbiota in the FT and to assess its relationship with OC. Eighty-one OC and 106 non-cancer patients were enrolled and 1001 swabs were processed for 16S rRNA gene PCR and sequencing. We identified 84 bacterial species that may represent the FT microbiota and found a clear shift in the microbiota of the OC patients when compared to the non-cancer patients. Of the top 20 species that were most prevalent in the FT of OC patients, 60% were bacteria that predominantly reside in the gastrointestinal tract, while 30% normally reside in the mouth. Serous carcinoma had higher prevalence of almost all 84 FT bacterial species compared to the other OC subtypes. The clear shift in the FT microbiota in OC patients establishes the scientific foundation for future investigation into the role of these bacteria in the pathogenesis of OC.

Vaginal Bacteria Elicit Acute Inflammatory Response in Fallopian Tube Organoids

To facilitate in vitro mechanistic studies in pelvic inflammatory disease and subsequent tubal factor infertility, we sought to establish patient tissue derived fallopian tube (FT) organoids and to study their inflammatory response to acute vaginal bacterial infection. FT tissues were obtained from four patients after salpingectomy for benign gynecological diseases. We introduced acute infection in the FT organoid culture system by inoculating the organoid culture media with two common vaginal bacterial species, Lactobacillus crispatus and Fannyhessea vaginae. The inflammatory response elicited in the organoids after acute bacterial infection was analyzed by the expression profile of 249 inflammatory genes. Compared to the negative controls that were not cultured with any bacteria, the organoids cultured with either bacterial species showed multiple differentially expressed inflammatory genes. Marked differences were noted between the Lactobacillus crispatus infected organoids and those infected by Fannyhessea vaginae. Genes from the C-X-C motif chemokine ligand (CXCL) family were highly upregulated in Fannyhessea vaginae infected organoids. Flow cytometry showed that immune cells quickly disappeared during the organoid culture, indicating the inflammatory response observed with bacterial culture was generated by the epithelial cells in the organoids. In summary, we have shown that patient tissue derived FT organoids respond to acute bacterial infection with upregulation of inflammatory genes specific to different vaginal bacterial species. FT organoids is a useful in vitro model system to study the host-pathogen interaction during bacterial infection.

Gardnerella Species and their Association with Bacterial Vaginosis

BACKGROUND

Bacterial vaginosis (BV) is a condition marked by high vaginal bacterial diversity. Gardnerella vaginalis has been implicated in BV but is also detected in healthy women. The Gardnerella genus has been expanded to encompass six validly named species and several genomospecies. We hypothesized that particular Gardnerella species may be more associated with BV.

METHODS

Quantitative PCR assays were developed targeting the cpn60 gene of species groups including G. vaginalis, G. piotii/pickettii, G. swidsinskii/greenwoodii and G. leopoldii. These assays were applied to vaginal swabs from individuals with (n=101) and without BV (n=150) attending a sexual health clinic in Seattle, Washington. Weekly swabs were collected from 42 participants for up to 12 weeks.

RESULTS

Concentrations and prevalence of each Gardnerella species group were significantly higher in participants with BV. 91.1% of BV positive participants had three or more Gardnerella species groups detected compared to 32.0% of BV negative participants (p<0.0001). BV negative participants with three or more species groups detected were more likely to develop BV within 100 days versus those with fewer (60.5% vs 3.7%, p<0.0001).

CONCLUSIONS

These results suggest that BV reflects a state of high Gardnerella species diversity. No Gardnerella species group was a specific marker for BV.

IgA coating of vaginal bacteria is reduced in the setting of bacterial vaginosis (BV) and preferentially targets BV-associated species

Immunoglobulin (Ig) bacterial coating has been described in the gastrointestinal tract and linked to inflammatory bowel disease; however, little is known about Ig coating of vaginal bacteria and whether it plays a role in vaginal health including bacterial vaginosis (BV). We examined Ig coating in 18 women with symptomatic BV followed longitudinally before, 1 week, and 1 month after oral metronidazole treatment. Immunoglobulin A (IgA) and/or immunoglobulin G (IgG) coating of vaginal bacteria was assessed by flow cytometry, and Ig coated and uncoated bacteria were sorted and characterized using 16S rRNA sequencing. Despite higher levels of IgG compared to IgA in cervicovaginal fluid, the predominant Ig coating the bacteria was IgA. The majority of bacteria were uncoated at all visits, but IgA coating significantly increased after treatment for BV. Despite similar amounts of uncoated and IgA coated majority taxa ( >1% total) across all visits, there was preferential IgA coating of minority taxa (0.2%-1% total) associated with BV including Sneathia, several Prevotella species, and others. At the time of BV, we identified a principal component (PC) driven by proinflammatory mediators that correlated positively with an uncoated BV-associated bacterial community and negatively with an IgA coated protective Lactobacillus bacterial community. The preferential coating of BV-associated species, increase in coating following metronidazole treatment, and positive correlation between uncoated BV-associated species and inflammation suggest that coating may represent a host mechanism designed to limit bacterial diversity and reduce inflammatory responses. Elucidating the role of Ig coating in vaginal mucosal immunity may promote new strategies to prevent recurrent BV.

Identification of fallopian tube microbiota and its association with ovarian cancer: a prospective study of intraoperative swab collections from 187 patients

Investigating the human fallopian tube (FT) microbiota has significant implications for understanding the pathogenesis of ovarian cancer (OC). In this large prospective study, we collected swabs intraoperatively from the FT and other surgical sites as controls to profile the microbiota in the FT and to assess its relationship with OC. 81 OC and 106 non-cancer patients were enrolled and 1001 swabs were processed for 16S rRNA gene PCR and sequencing. We identified 84 bacterial species that may represent the FT microbiota and found a clear shift in the microbiota of the OC patients when compared to the non-cancer patients. Of the top 20 species that were most prevalent in the FT of OC patients, 60% were bacteria that predominantly reside in the gastrointestinal tract, while 30% normally reside in the mouth. Serous carcinoma had higher prevalence of almost all 84 FT bacterial species compared to the other OC subtypes. The clear shift in the FT microbiota in OC patients establishes the scientific foundation for future investigation into the role of these bacteria in the pathogenesis of ovarian cancer. .

Amygdalobacter indicium gen. nov., sp. nov., and Amygdalobacter nucleatus sp. nov., gen. nov.: novel bacteria from the family Oscillospiraceae isolated from the female genital tract

Four obligately anaerobic Gram-positive bacteria representing one novel genus and two novel species were isolated from the female genital tract. Both novel species, designated UPII 610-JT and KA00274T, and an additional isolate of each species were characterized utilizing biochemical, genotypic and phylogenetic analyses. All strains were non-motile and non-spore forming, asaccharolytic, non-cellulolytic and indole-negative coccobacilli. Fatty acid methyl ester analysis for UPII 610-JT and KA00274T and additional isolates revealed C16 : 0, C18 : 0, C18:1ω9c and C18:2ω6,9c to be the major fatty acids for both species. UPII 610-JT had a 16S rRNA gene sequence similarity of 99.4 % to an uncultured clone sequence (AY724740) designated as Bacterial Vaginosis Associated Bacterium 2 (BVAB2). KA00274T had a 16S rRNA gene sequence similarity of 96.5 % to UPII 610-JT. Whole genomic DNA mol% G+C content was 42.2 and 39.3 % for UPII 610-JT and KA00274T, respectively. Phylogenetic analyses indicate these isolates represent a novel genus and two novel species within the Oscillospiraceae family. We propose the names Amygdalobacter indicium gen. nov., sp. nov., for UPII 610-JT representing the type strain of this species (=DSM 112989T, =ATCC TSD-274T) and Amygdalobacter nucleatus gen. nov., sp. nov., for KA00274T representing the type strain of this species (=DSM 112988T, =ATCC TSD-275T).

Optimizing metaproteomics database construction: lessons from a study of the vaginal microbiome

Metaproteomics, a method for untargeted, high-throughput identification of proteins in complex samples, provides functional information about microbial communities and can tie functions to specific taxa. Metaproteomics often generates less data than other omics techniques, but analytical workflows can be improved to increase usable data in metaproteomic outputs. Identification of peptides in the metaproteomic analysis is performed by comparing mass spectra of sample peptides to a reference database of protein sequences. Although these protein databases are an integral part of the metaproteomic analysis, few studies have explored how database composition impacts peptide identification. Here, we used cervicovaginal lavage (CVL) samples from a study of bacterial vaginosis (BV) to compare the performance of databases built using six different strategies. We evaluated broad versus sample-matched databases, as well as databases populated with proteins translated from metagenomic sequencing of the same samples versus sequences from public repositories. Smaller sample-matched databases performed significantly better, driven by the statistical constraints on large databases. Additionally, large databases attributed up to 34% of significant bacterial hits to taxa absent from the sample, as determined orthogonally by 16S rRNA gene sequencing. We also tested a set of hybrid databases which included bacterial proteins from NCBI RefSeq and translated bacterial genes from the samples. These hybrid databases had the best overall performance, identifying 1,068 unique human and 1,418 unique bacterial proteins, ~30% more than a database populated with proteins from typical vaginal bacteria and fungi. Our findings can help guide the optimal identification of proteins while maintaining statistical power for reaching biological conclusions. IMPORTANCE Metaproteomic analysis can provide valuable insights into the functions of microbial and cellular communities by identifying a broad, untargeted set of proteins. The databases used in the analysis of metaproteomic data influence results by defining what proteins can be identified. Moreover, the size of the database impacts the number of identifications after accounting for false discovery rates (FDRs). Few studies have tested the performance of different strategies for building a protein database to identify proteins from metaproteomic data and those that have largely focused on highly diverse microbial communities. We tested a range of databases on CVL samples and found that a hybrid sample-matched approach, using publicly available proteins from organisms present in the samples, as well as proteins translated from metagenomic sequencing of the samples, had the best performance. However, our results also suggest that public sequence databases will continue to improve as more bacterial genomes are published.

Changes in Vaginal Bacteria and Inflammatory Mediators From Periconception Through the Early Postpartum Period in a Cohort of Kenyan Women Without HIV

BACKGROUND

Women's increased risk of HIV acquisition during pregnancy and postpartum may be mediated by changes in vaginal microbiota and/or cytokines.

METHODS

A cohort of 80 Kenyan women who were HIV-1 seronegative contributed 409 vaginal samples at 6 pregnancy time points: periconception, positive pregnancy test result, first trimester, second trimester, third trimester, and postpartum. Concentrations of vaginal bacteria linked with HIV risk and Lactobacillus spp were measured using quantitative polymerase chain reaction. Cytokines were measured by immunoassay.

RESULTS

Based on Tobit regression, later pregnancy time points were associated with lower concentrations of Sneathia spp (P = .01), Eggerthella sp type 1 (P = .002), and Parvimonas sp type 2 (P = .02) and higher concentrations of Lactobacillus iners (P < .001), Lactobacillus crispatus (P < .001), Lactobacillus vaginalis (P < .001), interleukin 6 (P < .001), TNF (P = .004), C-X-C motif chemokine ligand 10 (CXCL10; P < .001), C-C motif ligand 3 (P = .009), C-C motif ligand 4 (P < .001), C-C motif ligand 5 (P = .002), interleukin 1β (P = .02), and interleukin 8 (P = .002). Most cervicovaginal cytokines and vaginal bacteria clustered separately in principal component analysis, except for CXCL10, which did not group with either cytokines or bacteria. The shift toward a Lactobacillus-dominated microbiota during pregnancy mediated the relationship between pregnancy time point and CXCL10.

CONCLUSIONS

Increases in proinflammatory cytokines, but not vaginal bacterial taxa linked with higher HIV risk, could provide an explanation for increased HIV susceptibility during pregnancy and postpartum.

Intestinal microbiota controls graft-versus-host disease independent of donor-host genetic disparity

Acute graft-versus-host disease (aGVHD) remains a major limitation of allogeneic stem cell transplantation (SCT), and severe intestinal manifestation is the major cause of early mortality. Intestinal microbiota control MHC class II (MHC-II) expression by ileal intestinal epithelial cells (IECs) that promote GVHD. Here, we demonstrated that genetically identical mice of differing vendor origins had markedly different intestinal microbiota and ileal MHC-II expression, resulting in discordant GVHD severity. We utilized cohousing and antibiotic treatment to characterize the bacterial taxa positively and negatively associated with MHC-II expression. A large proportion of bacterial MHC-II inducers were vancomycin sensitive, and peri-transplant oral vancomycin administration attenuated CD4+ T cell-mediated GVHD. We identified a similar relationship between pre-transplant microbes, HLA class II expression, and both GVHD and mortality in a large clinical SCT cohort. These data highlight therapeutically tractable mechanisms by which pre-transplant microbial taxa contribute to GVHD independently of genetic disparity.

Next generation sequencing to examine associations between vaginal washing and vaginal microbiota: A cohort study

BACKGROUND

The association between vaginal washing and HIV risk may be mediated by vaginal washing-associated changes in vaginal microbiota.

METHODS

Data from a cohort of HIV-negative US and Kenyan women enrolled in the Preventing Vaginal Infections trial were analyzed. Vaginal fluid samples and vaginal washing data were collected every 2 months for 12 months. Bacterial relative abundances were measured by broad-range 16S rRNA gene polymerase chain reaction with next generation sequencing. Generalized estimating equations were used to evaluate the association between vaginal washing and i) the Shannon Diversity Index (SDI); and ii) mean change in percent bacterial relative abundances, with application of a 10% false discovery rate (FDR).

RESULTS

Participants (N = 111) contributed 93/630 (14.8%) vaginal washing visits. Mean SDI was 0.74 points higher (95% CI 0.35, 1.14; p < 0.001) at washing visits among US participants (N = 26). Vaginal washing was not associated with SDI in Kenyan participants (N = 85). There were no associations between vaginal washing and vaginal bacterial relative abundances after applying the FDR.

CONCLUSIONS

The discordant results in Kenyan versus US women suggests the link between vaginal washing and sub-optimal vaginal microbiota may be context specific. Vaginal microbial shifts may not fully explain the association between vaginal washing and HIV acquisition.

Analysis of Antibiotic Exposure and Development of Acute Graft-vs-Host Disease Following Allogeneic Hematopoietic Cell Transplantation

Importance

Certain antibiotic exposures have been associated with increased rates of acute graft-vs-host disease (aGVHD) after allogeneic hematopoietic cell transplantation (allo-HCT). Since antibiotic exposure can both affect and be affected by infections, analyzing time-dependent exposure in the presence of multiple potential confounders, including prior antibiotic exposures, poses specific analytical challenges, necessitating both a large sample size and unique approaches.

Objective

To identify antibiotics and antibiotic exposure timeframes associated with subsequent aGVHD.

Design, Setting, and Participants

This cohort study assessed allo-HCT at a single center from 2010 to 2021. Participants included all patients aged at least 18 years who underwent their first T-replete allo-HCT, with at least 6 months of follow-up. Data were analyzed from August 1 to December 15, 2022.

Exposures

Antibiotics between 7 days before and 30 days after transplant.

Main Outcomes and Measures

The primary outcome was grade II to IV aGVHD. The secondary outcome was grade III to IV aGVHD. Data were analyzed using 3 orthogonal methods: conventional Cox proportional hazard regression, marginal structural models, and machine learning.

Results

A total of 2023 patients (median [range] age, 55 [18-78] years; 1153 [57%] male) were eligible. Weeks 1 and 2 after HCT were the highest-risk intervals, with multiple antibiotic exposures associated with higher rates of subsequent aGVHD. In particular, exposure to carbapenems during weeks 1 and 2 after allo-HCT was consistently associated with increased risk of aGVHD (minimum hazard ratio [HR] among models, 2.75; 95% CI, 1.77-4.28), as was week 1 after allo-HCT exposure to combinations of penicillins with a β-lactamase inhibitor (minimum HR among models, 6.55; 95% CI, 2.35-18.20).

Conclusions and Relevance

In this cohort study of allo-HCT recipients, antibiotic choices and schedules in the early course of transplantation were associated with aGVHD rates. These findings should be considered in antibiotic stewardship programs.

Vaginal bacteria elicit acute inflammatory response in fallopian tube organoids: a model for pelvic inflammatory disease

Objective: To facilitate in vitro mechanistic studies in pelvic inflammatory disease (PID) and subsequent tubal factor infertility, as well as ovarian carcinogenesis, we sought to establish patient tissue derived fallopian tube (FT) organoids and to study their inflammatory response to acute vaginal bacterial infection. Design: Experimental study. Setting: Academic medical and researchcenter. Patients: FT tissues were obtained from four patients after salpingectomy for benign gynecological diseases. Interventions: We introduced acute infection in the FT organoid culture system by inoculating the organoid culture media with two common vaginal bacterial species, Lactobacillus crispatus and Fannyhesseavaginae . Main Outcome Measures: The inflammatory response elicited in the organoids after acute bacterial infection was analyzed by the expression profile of 249 inflammatory genes. Results: Compared to the negative controls that were not cultured with any bacteria, the organoids cultured with either bacterial species showed multiple differentially expressed inflammatory genes. Marked differences were noted between the Lactobacillus crispatus infected organoids and those infected by Fannyhessea vaginae . Genes from the C-X-C motif chemokine ligand (CXCL) family were highly upregulated in F. vaginae infected organoids. Flow cytometry showed that immune cells quickly disappeared during the organoid culture, indicating the inflammatory response observed with bacterial culture was generated by the epithelial cells in the organoids. Conclusion : Patient tissue derived FT organoids respond to acute bacterial infection with upregulation of inflammatory genes specific to different vaginal bacterial species. FT organoids is a useful model system to study the host-pathogen interaction during bacterial infection which may facilitate mechanistic investigations in PID and its contribution to tubal factor infertility and ovarian carcinogenesis.

Economic Evaluation of a Point-of-Care Test for Bacterial Vaginosis Among Women With Vaginal Symptoms

BACKGROUND

There is an unmet need for a clinical diagnostic technology to detect bacterial vaginosis (BV) rapidly and accurately. Novel point-of-care (POC) tests have the potential to fulfill this gap. Our objective was to determine the cost-effectiveness of a hypothetical clinician-administered POC test for diagnosing BV in the United States.

METHODS

We developed a state-transition microsimulation model to evaluate the cost-effectiveness of using the POC test versus usual care among women of reproductive age with vaginal symptoms. We adopted a healthcare sector perspective that included relevant healthcare costs and a societal perspective that further incorporated productivity costs. Model parameters were empirically estimated based on commercial insurance claims data or derived from published literature. The primary model outcome was incremental cost-effectiveness ratio. We started with analyzing a hypothetical POC test with a sensitivity and specificity of 0.9 and a cost of $40, followed by extensive sensitivity analyses.

RESULTS

Using the hypothetical POC test to diagnose BV increased costs by $16 and quality-adjusted life-years by 0.0005 per person compared with the usual care, leading to an incremental cost-effectiveness ratio of $31,108 per quality-adjusted life-year gained. When also capturing the productivity costs, the POC test resulted in an average cost savings of $57. The sensitivity analyses showed that the POC test's sensitivity was more influential on its cost-effectiveness than specificity.

CONCLUSIONS

Using the POC test to diagnose BV is likely to be cost-effective relative to usual care, especially with a high sensitivity or a substantial positive effect on productivity.

Vaginal bacteria elicit acute inflammatory response in fallopian tube organoids: a model for pelvic inflammatory disease

Objective

To facilitate in vitro mechanistic studies in pelvic inflammatory disease (PID) and subsequent tubal factor infertility, as well as ovarian carcinogenesis, we sought to establish patient tissue derived fallopian tube (FT) organoids and to study their inflammatory response to acute vaginal bacterial infection.

Design

Experimental study.

Setting

Academic medical and research center.

Patients

FT tissues were obtained from four patients after salpingectomy for benign gynecological diseases.

Interventions

We introduced acute infection in the FT organoid culture system by inoculating the organoid culture media with two common vaginal bacterial species, Lactobacillus crispatus and Fannyhessea vaginae .

Main Outcome Measures

The inflammatory response elicited in the organoids after acute bacterial infection was analyzed by the expression profile of 249 inflammatory genes.

Results

Compared to the negative controls that were not cultured with any bacteria, the organoids cultured with either bacterial species showed multiple differentially expressed inflammatory genes. Marked differences were noted between the Lactobacillus crispatus infected organoids and those infected by Fannyhessea vaginae . Genes from the C-X-C motif chemokine ligand (CXCL) family were highly upregulated in F. vaginae infected organoids. Flow cytometry showed that immune cells quickly disappeared during the organoid culture, indicating the inflammatory response observed with bacterial culture was generated by the epithelial cells in the organoids.

Conclusion

Patient tissue derived FT organoids respond to acute bacterial infection with upregulation of inflammatory genes specific to different vaginal bacterial species. FT organoids is a useful model system to study the host-pathogen interaction during bacterial infection which may facilitate mechanistic investigations in PID and its contribution to tubal factor infertility and ovarian carcinogensis.

The Incidence Rate of Sexual Behaviors Among Cisgender Men Who Have Sex with Men Attending a Sexual Health Clinic

Although nuanced parameterization of sexual behavior may improve estimates from mathematical models of human immunodeficiency virus and sexually transmitted infection transmission, prospective estimates of the incidence of specific sexual behaviors among men who have sex with men (MSM) are limited. From December 2014 to July 2018, MSM with and without nongonococcal urethritis (NGU) completed weekly diaries over 3-12 weeks. Incidence rates of any sex, receptive anal sex, insertive anal sex, insertive oral sex, receptive rimming, and receptive hand-penile contact were 1.19, 0.28, 0.66, 0.90, 0.24, and 0.85 episodes per person-week, respectively, among 104 MSM with NGU at baseline, and 1.33, 0.54, 0.32, 0.95, 0.44, and 0.88 episodes per person-week, respectively, among 25 MSM without NGU at baseline. Most receptive anal sex (NGU + 83%, NGU - 86%) and insertive anal sex (NGU + 85%, NGU - 76%) episodes were condomless. MSM engaged in sex just over once per week, and condom use was infrequent. Insertive oral sex and receptive hand-penile contact were the most common behaviors.

Bacterial vaginosis-associated bacteria in cisgender men who have sex with women: prevalence, association with non-gonococcal urethritis and natural history

OBJECTIVES

Bacterial vaginosis-associated bacterium 2 (BVAB2), Mageeibacillus indolicus and Sneathia spp are highly predictive of bacterial vaginosis (BV) in cisgender women. They have been associated with non-gonococcal urethritis (NGU) in cisgender men in some but not all populations. We evaluated this association in a cross-sectional study of cisgender men who have sex with women only (MSW).

METHODS

MSW without gonorrhoea attending a sexual health clinic (SHC) from 2014 to 2018 completed a computer-assisted self-interview, clinical interview and examination. NGU was defined as ≥5 polymorphonuclear leucocytes/high-power field in urethral exudates plus either urethral symptoms or visible discharge. Urine was tested for Chlamydia trachomatis and Mycoplasma genitalium using Aptima (Hologic) and for BVAB2, M. indolicus, Sneathia spp, Trichomonas vaginalis, Ureaplasma urealyticum, Haemophilus influenzae, herpes simplex virus and adenovirus using quantitative PCR.

RESULTS

Of 317 MSW age 17-71, 67 (21.1%) had Sneathia spp, 36 (11.4%) had BVAB2, and 17 (5.4%) had M. indolicus at enrolment. Having ≥3 partners in the past 2 months was the only characteristic that was more common among MSW with than those without these bacteria (BVAB2: 47% vs 23%, M. indolicus: 53% vs 24%, Sneathia spp: 42% vs 22%; p≤0.03 for all). One-hundred seventeen men (37%) were diagnosed with NGU at enrolment. There was no significant association of BVAB2, M. indolicus or Sneathia spp with NGU (adjusted OR=0.59, 95% CI 0.14 to 2.43; aOR=3.40, 95% CI 0.68 to 17.06; aOR=0.46, 95% CI 0.16 to 1.27). Of 109 MSW with monthly samples, 34 (31.2%) had one of the bacteria at one or more follow-up visits, 22 of which were co-colonised with >1. Median persistence over 6 months did not differ significantly (BVAB2=30.5 days, IQR=28-87; M. indolicus=87 days, IQR=60-126; Sneathia spp=70 days, IQR=30-135; p≥0.20 for each comparison).

CONCLUSIONS

Neither BVAB2, M. indolicus nor Sneathia spp were associated with increased risk of prevalent NGU in MSW attending an SHC.

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.

Impact of Topical Interventions on the Vaginal Microbiota and Metabolome in Postmenopausal Women: A Secondary Analysis of a Randomized Clinical Trial

IMPORTANCE

Postmenopausal women with genitourinary symptoms of menopause are often prescribed vaginal estradiol or moisturizer for symptom improvement, but the impact of these treatments on the local microenvironment is poorly understood.

OBJECTIVE

To compare changes in the vaginal microbiota, metabolome, and pH among women using low-dose vaginal estradiol tablet or low pH moisturizer gel for 12-weeks vs low pH placebo.

DESIGN, SETTING, AND PARTICIPANTS

This is a post hoc prespecified secondary analysis of a 12-week multicenter randomized clinical trial among postmenopausal women with moderate to severe genitourinary symptoms. Women were enrolled between April 2016 and February 2017; final follow-up visits occurred in April 2017. Data were analyzed from November 2018 to July 2021.

INTERVENTIONS

Ten-μg vaginal estradiol plus placebo gel vs placebo tablet plus vaginal moisturizer vs dual placebo.

MAIN OUTCOMES AND MEASURES

The main outcome measures were changes in the diversity and composition of the vaginal microbiota, changes in the metabolome, and pH.

RESULTS

Of 302 postmenopausal women from the parent trial, 144 women (mean [SD] age, 61 [4] years) were included in this analysis. After 12 weeks, the microbiota was dominated with Lactobacillus and Bifidobacterium communities among 36 women (80%) in the estradiol group, compared with 16 women (36%) using moisturizer and 13 women (26%) using placebo (P < .001). The composition of vaginal fluid metabolites also varied after 12-weeks among women in the estradiol group with significant changes in 90 of 171 metabolites measured (53%) (P < .001), including an increase in lactate. The 12-week pH among women in the estradiol group was lower vs placebo (median [IQR] pH, 5 [4.5-6.0] vs 6 [5.5-7.0]; P = .005) but not the moisturizer group vs placebo (median [IQR] pH, 6 [5.5-6.5]; P = .28). There was a decrease in pH from baseline to 12-weeks within the moisturizer (median [IQR] pH, 7 [6.0-7.5] vs 6 [5.5-6.5]; P < .001) and placebo (median [IQR] pH, 7 [7.0-7.5] vs 6 [5.5-7.0]; P < .001) groups. Women with high-diversity bacterial communities at baseline exhibited greater median change in pH compared with women with low-diversity communities (median [IQR] change, -1 [-2 to -0.5] vs -0.3 [-1.1 to 0], P = .007).

CONCLUSIONS AND RELEVANCE

This secondary analysis of a randomized clinical trial found that use of vaginal estradiol tablets resulted in substantial changes in the vaginal microbiota and metabolome with a lowering in pH, particularly in women with high-diversity bacterial communities at baseline. Low pH moisturizer or placebo did not significantly impact the vaginal microbiota or metabolome despite lowering the vaginal pH. Estradiol use may offer additional genitourinary health benefits to postmenopausal women.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02516202.

Diagnosis of infectious diseases in immunocompromised hosts using metagenomic next generation sequencing-based diagnostics

The diagnosis of infectious diseases in immunocompromised hosts presents unique challenges for the clinician. Metagenomic next generation sequencing (mNGS) based diagnostics that identify microbial nucleic acids in clinical samples (mNGS for pathogen identification or mNGSpi) may be a useful tool in addressing some of these challenges. Studies of mNGSpi in immunocompromised hosts have demonstrated that these diagnostics are capable of identifying causative organisms in a subset of patients for whom conventional testing has been negative. While these studies provide proof of concept for mNGSpi utility, they have a number of limitations, which make it difficult to confidently assess test performance and clinical impact based on current data. Future studies will likely feature larger cohort sizes and controlled interventional study designs that assess the impact of mNGSpi on clinical endpoints. They will also likely include assessments of the clinical value of data generated by mNGS beyond pathogen identification.

Vaginal Bacteria and Risk of Incident and Persistent Infection With High-Risk Subtypes of Human Papillomavirus: A Cohort Study Among Kenyan Women

BACKGROUND

Bacterial vaginosis (BV) is associated with an increased risk of high-risk human papillomavirus (hrHPV), whereas Lactobacillus-dominated vaginal microbiotas are associated with reduced burden of hrHPV. Few epidemiologic studies have prospectively investigated the relationships between vaginal bacteria and hrHPV, particularly among women from countries in Africa.

METHODS

We conducted a prospective cohort study nested within the Preventing Vaginal Infections trial to evaluate associations between vaginal bacteria and hrHPV incidence and persistence. Sexually active, HIV-seronegative women aged 18 to 45 years who had a vaginal infection at screening were eligible to enroll. Analyses were restricted to participants enrolled in Kenya and randomized to placebo. At enrollment and months 2, 4, 6, 8, 10, and 12, hrHPV testing, quantitative polymerase chain reaction (measuring taxon quantity per swab), and 16S rRNA gene amplicon sequencing of the vaginal microbiota were performed. Generalized estimating equations multinomial logistic regression models were fit to evaluate associations between vaginal bacteria and incident and persistent hrHPV.

RESULTS

Eighty-four participants were included in this analysis. Higher concentrations of Lactobacillus crispatus were inversely associated with persistent hrHPV detection. Specifically, 1 tertile higher L. crispatus concentration was associated with 50% reduced odds of persistent hrHPV detection (odds ratio, 0.50; 95% confidence interval, 0.29-0.85).

CONCLUSIONS

This study is consistent with reports that vaginal L. crispatus is associated with reduced susceptibility to hrHPV persistence. Evidence from in vitro studies provides insight into potential mechanisms by which L. crispatus may mediate hrHPV risk. Future studies should further explore in vivo mechanisms that may drive this relationship and opportunities for intervention.

Influence of Intramuscular Depot Medroxyprogesterone Acetate Initiation on Vaginal Microbiota in the Postpartum Period

BACKGROUND

The vaginal microbiome plays a key role in women's reproductive health. Use of exogenous hormones, such as intramuscular depot medroxyprogesterone acetate (DMPA-IM), may alter the composition of vaginal bacterial community.

METHODS

Vaginal swab samples were collected from postpartum Kenyan women initiating DMPA-IM or nonhormonal contraception (non-HC). Bacterial vaginosis was assessed by Nugent score (Nugent-BV) and bacterial community composition was evaluated using broad-range 16S ribosomal RNA gene polymerase chain reaction with high-throughput sequencing. Changes in Nugent score, alpha diversity (Shannon diversity index), and total bacterial load between contraceptive groups from enrollment to 3 months after initiation were estimated using multivariable linear mixed effects regression.

RESULTS

Among 54 human immunodeficiency virus-negative women, 33 choosing DMPA-IM and 21 choosing non-HC, Nugent-BV was more common among DMPA-IM users at enrollment. At follow-up, Nugent score had decreased significantly among DMPA-IM users (change, -1.89; 95% confidence interval [CI], -3.53 to -.25; P = .02) while alpha diversity remained stable (0.03; -.24 to .30; P = .83). Conversely, Nugent score remained relatively stable among non-HC users (change, -0.73; 95% CI, -2.18 to .73; P = .33) while alpha diversity decreased (-0.34; -.67 to -.001; P = .05). The total bacterial load decreased slightly in DMPA-IM users and increased slightly among non-HC users, resulting in a significant difference in change between the contraceptive groups (difference, -0.64 log10 gene copies per swab sample; 95% CI, -1.19 to -.08; P = .02). While significant changes in Nugent score and alpha diversity were observed within contraceptive groups, changes between groups were not significantly different.

CONCLUSIONS

Postpartum vaginal bacterial diversity did not change in DMPA-IM users despite a reduction in Nugent-BV, but it decreased significantly among women using non-HC. Choice of contraception may influence Lactobacillus recovery in postpartum women.

COVID-19-Lessons Learned and Questions Remaining

In this article, the editors of Clinical Infectious Diseases review some of the most important lessons they have learned about the epidemiology, clinical features, diagnosis, treatment and prevention of SARS-CoV-2 infection and identify essential questions about COVID-19 that remain to be answered.

Differences in vaginal microbiota, host transcriptome and proteins in women with bacterial vaginosis are associated with metronidazole treatment response

BACKGROUND

Bacterial vaginosis (BV) treatment failures and recurrences are common. To identify features associated with treatment response, we compared vaginal microbiota and host ectocervical transcriptome before and after oral metronidazole therapy.

METHODS

Women with BV (Bronx, NY and Thika, Kenya) received 7 days of oral metronidazole at enrollment (Day 0) and underwent genital tract sampling of microbiome (16S rRNA gene sequencing), transcriptome (RNAseq), and immune mediator concentrations on Day 0, 15 and 35.

RESULTS

Bronx participants were more likely than Thika participants to clinically respond to metronidazole (19/20 vs 10/18, respectively, p=0.0067) and by changes in microbiota composition and diversity. After dichotomizing the cohort into responders and non-responders by change in alpha diversity between Day 35 and Day 0, we identified transcription differences associated with chemokine signaling (q=0.002) and immune system process (q=2.5e-8) that differentiated responders from non-responders were present at enrollment. Responders had significantly lower levels of CXCL9 in cervicovaginal lavage on Day 0 (p< 0.007) and concentrations of CXCL9, CXCL10 and MCP-1 increased significantly between Day 0 and Day 35 in responders versus non-responders.

CONCLUSIONS

Response to metronidazole is characterized by significant changes in chemokines and related transcripts suggesting that treatments that promote these pathways may prove beneficial.

Association Between Vaginal Bacterial Microbiota and Vaginal Yeast Colonization

BACKGROUND

Vaginal yeast is frequently found with Lactobacillus-dominant microbiota. The relationship between vaginal yeast and other bacteria has not been well characterized.

METHODS

These analyses utilized data from the Preventing Vaginal Infections trial. Relative abundance of vaginal bacteria from 16S ribosomal ribonucleic acid gene amplicon sequencing and quantities of 10 vaginal bacteria using taxon-directed polymerase chain reaction assays were compared at visits with and without detection of yeast on microscopy, culture, or both.

RESULTS

Higher relative abundances of Megasphaera species type 1 (risk ratio [RR], 0.70; 95% confidence interval [CI], 0.52-0.95), Megasphaera species type 2 (RR, 0.81; 95% CI, 0.67-0.98), and Mageeibacillus indolicus (RR, 0.46; 95% CI, 0.25-0.83) were associated with lower risk of detecting yeast. In contrast, higher relative abundances of Bifidobacterium bifidum, Aerococcus christensenii, Lactobacillus mucosae, Streptococcus equinus/infantarius/lutentiensis, Prevotella bivia, Dialister propionicifaciens, and Lactobacillus crispatus/helveticus were associated with yeast detection. Taxon-directed assays confirmed that increasing quantities of both Megasphaera species and M indolicus were associated with lower risk of detecting yeast, whereas increasing quantities of L crispatus were associated with higher risk of detecting yeast.

CONCLUSIONS

Despite an analysis that examined associations between multiple vaginal bacteria and the presence of yeast, only a small number of vaginal bacteria were strongly and significantly associated with the presence or absence of yeast.

Megasphaera lornae sp. nov., Megasphaera hutchinsoni sp. nov., and Megasphaera vaginalis sp. nov.: novel bacteria isolated from the female genital tract

Six strictly anaerobic Gram-negative bacteria representing three novel species were isolated from the female reproductive tract. The proposed type strains for each species were designated UPII 199-6^T, KA00182^T and BV3C16-1^T. Phylogenetic analyses based on 16S rRNA gene sequencing indicated that the bacterial isolates were members of the genus Megasphaera. UPII 199-6^T and KA00182^T had 16S rRNA gene sequence identities of 99.9 % with 16S rRNA clone sequences previously amplified from the human vagina designated as Megasphaera type 1 and Megasphaera type 2, members of the human vaginal microbiota associated with bacterial vaginosis, preterm birth and HIV acquisition. UPII 199-6^T exhibited sequence identities ranging from 92.9 to 93.6 % with validly named Megasphaera isolates and KA00182^T had 16S rRNA gene sequence identities ranging from 92.6-94.2 %. BV3C16-1^T was most closely related to Megasphaera cerevisiae with a 16S rRNA gene sequence identity of 95.4 %. Cells were coccoid or diplococcoid, non-motile and did not form spores. Genital tract isolates metabolized organic acids but were asaccharolytic. The isolates also metabolized amino acids. The DNA G+C content for the genome sequences of UPII 199-6^T, KA00182^T and BV3C16-1^T were 46.4, 38.9 and 49.8 mol%, respectively. Digital DNA-DNA hybridization and average nucleotide identity between the genital tract isolates and other validly named Megasphaera species suggest that each isolate type represents a new species. The major fatty acid methyl esters include the following: C_12 : 0, C_16 : 0, C_16 : 0 dimethyl acetal (DMA) and summed feature 5 (C_15 : 0 DMA and/or C_14 : 0 3-OH) in UPII 199-6^T; C_16 : 0 and C_16 : 1 cis 9 in KA00182^T; C_12 : 0; C_14 : 0 3-OH; and summed feature 5 in BV3C16-1^T. The isolates produced butyrate, isobutyrate, and isovalerate but there were specific differences including production of formate and propionate. Together, these data indicate that UPII 199-6^T, KA00182^T and BV3C16-1^T represent novel species within the genus Megasphaera. We propose the following names: Megasphaera lornae sp. nov. for UPII 199-6^T representing the type strain of this species (=DSM 111201^T=ATCC TSD-205^T), Megasphaera hutchinsoni sp. nov. for KA00182^T representing the type strain of this species (=DSM 111202^T=ATCC TSD-206^T) and Megasphaera vaginalis sp. nov. for BV3C16-1^T representing the type strain of this species (=DSM 111203^T=ATCC TSD-207^T).

Bacterial Communities Associated With Abnormal Nugent Score in Postmenopausal Versus Premenopausal Women

The Nugent score is the reference standard for bacterial vaginosis (BV) diagnosis but has not been validated in postmenopausal women. We compared relative abundances from 16S ribosomal RNA gene sequencing of vaginal microbiota with Nugent score in cohorts of premenopausal (n = 220) and postmenopausal (n = 144) women. In premenopausal women, 33 taxa were significantly correlated with Nugent score, including the classic BV-associated taxa Gardnerella, Atopobium, Sneathia, Megasphaera, and Prevotella. In postmenopausal women, 11 taxa were significantly associated with Nugent score, including Prevotella but no other BV-associated genera. High Nugent scores should not be used to infer BV in postmenopausal women.

Urethral Microbiota in Men: Association of Haemophilus influenzae and Mycoplasma penetrans With Nongonococcal Urethritis

BACKGROUND

Nongonococcal urethritis (NGU) is a common syndrome with no known etiology in ≤50% of cases. We estimated associations between urethral bacteria and NGU in men who have sex with men (MSM) and men who have sex with women (MSW).

METHODS

Urine was collected from NGU cases (129 MSM, 121 MSW) and controls (70 MSM, 114 MSW) attending a Seattle STD clinic. Cases had ≥5 polymorphonuclear leukocytes on Gram stain plus symptoms or discharge; controls had <5 PMNs, no symptoms, no discharge. NGU was considered idiopathic when Neisseria gonorrhoeae, Chlamydia trachomatis, Mycoplasma genitalium, Trichomonas vaginalis, adenovirus, and herpes simplex virus were absent. The urethral microbiota was characterized using 16S rRNA gene sequencing. Compositional lasso analysis was conducted to identify associations between bacterial taxa and NGU and to select bacteria for targeted qPCR.

RESULTS

Among NGU cases, 45.2% were idiopathic. Based on compositional lasso analysis, we selected Haemophilus influenzae (HI) and Mycoplasma penetrans (MP) for targeted qPCR. Compared with 182 men without NGU, the 249 men with NGU were more likely to have HI (14% vs 2%) and MP (21% vs 1%) (both P ≤ .001). In stratified analyses, detection of HI was associated with NGU among MSM (12% vs 3%, P = .036) and MSW (17% vs 1%, P < .001), but MP was associated with NGU only among MSM (13% vs 1%, P = .004). Associations were stronger in men with idiopathic NGU.

CONCLUSIONS

HI and MP are potential causes of male urethritis. MP was more often detected among MSM than MSW with urethritis.

Specific Vaginal Bacteria Are Associated With an Increased Risk of Trichomonas vaginalis Acquisition in Women

BACKGROUND

While bacterial vaginosis has been associated with an increased risk of Trichomonas vaginalis (TV) acquisition, it is unknown whether other characteristics of the vaginal microbiota, including the presence of key bacterial species, influence a woman's risk of TV acquisition.

METHODS

The vaginal microbiota before 25 unique episodes of TV infection involving 18 women was compared to that of 50 controls who remained uninfected. TV was detected by transcription-mediated amplification. Vaginal microbiota were quantified using broad-range polymerase chain reaction analysis and taxon-specific quantitative PCR of the 16S ribosomal RNA gene.

RESULTS

TV acquisition was significantly associated with the presence of Prevotella amnii (risk ratio [RR], 2.21; 95% confidence interval [CI], 1.12-4.38; P = .02) and Sneathia sanguinegens (RR, 2.58; 95% CI, 1.00-6.62; P = .049). When adjusted for menstrual phase, the association between P. amnii and TV acquisition remained similar (adjusted RR, 2.11; 95% CI, 1.03-4.33; P = .04), but the association between S. sanguinegens and TV acquisition was attenuated (adjusted RR, 2.31; 95% CI, .86-6.23; P = .10).

CONCLUSIONS

Key vaginal bacterial species may contribute to the susceptibility to TV acquisition. Understanding how these bacterial species increase a woman's risk of TV acquisition could help to guide the development of novel strategies to reduce women's risk of TV infection.

Extra-vaginal Bacterial Colonization and Risk for Incident Bacterial Vaginosis in a Population of Women who Have Sex with Men

Background

Bacterial vaginosis (BV) is a common cause of vaginal discharge and associated with vaginal acquisition of BV-associated bacteria (BVAB).

Methods

We used quantitative polymerase chain reaction assays to determine whether presence or concentrations of BVAB in the mouth, anus, vagina, or labia before BV predict risk of incident BV in 72 women who have sex with men.

Results

Baseline vaginal and extra-vaginal colonization with Gardnerella spp, Megasphaera spp, Sneathia spp, BVAB-2, Dialister sp type 2, and other BVAB was more common among subjects with incident BV.

Conclusions

Prior colonization with BVAB is a consistent risk for BV.

Primary Syphilis in the Male Urethra: A Case Report

We documented urethral Treponema pallidum infection in a man with nongonococcal urethritis and a negative syphilis serology using broad-range bacterial polymerase chain reaction (PCR) and sequencing, targeted PCR, and immunofluorescence microscopy. He subsequently seroconverted for syphilis. Early syphilis may present as urethritis. Urethral T. pallidum shedding can occur before seroconversion.

Complementing 16S rRNA Gene Amplicon Sequencing with Total Bacterial Load To Infer Absolute Species Concentrations in the Vaginal Microbiome

Whereas 16S rRNA gene amplicon sequencing quantifies relative abundances of bacterial taxa, variation in total bacterial load between samples restricts its ability to reflect absolute concentrations of individual bacterial species. Quantitative PCR (qPCR) can quantify individual species, but it is not practical to develop a suite of qPCR assays for every bacterium present in a diverse sample. We sought to determine the accuracy of an inferred measure of bacterial concentration using total bacterial load and relative abundance. We analyzed 1,320 samples from 20 women with a history of frequent bacterial vaginosis who self-collected vaginal swabs daily over 60 days. We inferred bacterial concentrations by taking the product of species relative abundance (assessed by 16S rRNA gene amplicon sequencing) and bacterial load (measured by broad-range 16S rRNA gene qPCR). Log10-converted inferred concentrations correlated with targeted qPCR (r = 0. 935, P < 2.2e-16) for seven key bacterial species. The mean inferred concentration error varied across bacteria, with rarer bacteria associated with larger errors. A total of 92% of the >0.5-log10 errors occurred when the relative abundance was <10%. Many errors occurred during early bacterial expansion from or late contraction to low abundance. When the relative abundance of a species is >10%, inferred concentrations are reliable proxies for targeted qPCR in the vaginal microbiome. However, targeted qPCR is required to capture bacteria at low relative abundance and is preferable for characterizing growth and decay kinetics of single species.IMPORTANCE Microbiome studies primarily use 16S rRNA gene amplicon sequencing to assess the relative abundance of bacterial taxa in a community. However, these measurements do not accurately reflect absolute taxon concentrations. We sought to determine whether the product of species' relative abundance and total bacterial load measured by broad-range qPCR is an accurate proxy for individual species' concentrations, as measured by taxon-specific qPCR assays. Overall, the inferred bacterial concentrations were a reasonable proxy of species-specific qPCR values, particularly when bacteria are present at a higher relative abundance. This approach offers an opportunity to assess the concentrations of bacterial species and how they change in a community over time without developing individual qPCR assays for each taxon.

Changes in key vaginal bacteria among postpartum African women initiating intramuscular depot-medroxyprogesterone acetate

Background

The ECHO trial has relieved apprehension about intramuscular depot medroxyprogesterone acetate (DMPA-IM), however it is still important to understand how DMPA-IM affects the vaginal environment. We sought to describe how DMPA-IM initiation influences vaginal bacteria associated with HIV acquisition in postpartum women.

Methods

Vaginal swabs were collected for Nugent score determination and taxon-specific quantitative PCR of eight bacteria. Enrollment occurred at contraceptive initiation (DMPA-IM or non-hormonal contraception (non-HC)) and repeat vaginal swabs were collected after three months. Generalized estimating equations were used to estimate changes in Nugent score, total bacterial load, and taxa concentrations among contraceptive groups.

Results

Women who chose DMPA-IM (n = 33) were more likely to be married (97%vs.67%) and have resumed intercourse since delivery (52%vs.29%) compared to women who chose non-HC (n = 21). After three months, significant decreases in the concentrations of Sneathia species, Mycoplasma hominis, and Parvimonas species Type 1 were seen among non-HC users, however concentrations remained stable among DMPA-IM users; contraceptive method was associated with significantly different changes in M. hominis concentration between groups (p = 0.010).

Conclusions

Our findings suggest that postpartum use of DMPA-IM and non-HC may have differential impacts on the vaginal concentrations of some bacteria that have previously been associated with HIV acquisition.

Impact of preconception vaginal microbiota on women's risk of spontaneous preterm birth: protocol for a prospective case-cohort study

INTRODUCTION

Bacterial vaginosis (BV) and vaginal microbiota disruption during pregnancy are associated with increased risk of spontaneous preterm birth (SPTB), but clinical trials of BV treatment during pregnancy have shown little or no benefit. An alternative hypothesis is that vaginal bacteria present around conception may lead to SPTB by compromising the protective effects of cervical mucus, colonising the endometrial surface before fetal membrane development, and causing low-level inflammation in the decidua, placenta and fetal membranes. This protocol describes a prospective case-cohort study addressing this hypothesis.

METHODS AND ANALYSIS

HIV-seronegative Kenyan women with fertility intent are followed from preconception through pregnancy, delivery and early postpartum. Participants provide monthly vaginal specimens during the preconception period for vaginal microbiota assessment. Estimated date of delivery is determined by last menstrual period and first trimester obstetrical ultrasound. After delivery, a swab is collected from between the fetal membranes. Placenta and umbilical cord samples are collected for histopathology. Broad-range 16S rRNA gene PCR and deep sequencing of preconception vaginal specimens will assess species richness and diversity in women with SPTB versus term delivery. Concentrations of key bacterial species will be compared using quantitative PCR (qPCR). Taxon-directed qPCR will also be used to quantify bacteria from fetal membrane samples and evaluate the association between bacterial concentrations and histopathological evidence of inflammation in the fetal membranes, placenta and umbilical cord.

ETHICS AND DISSEMINATION

This study was approved by ethics committees at Kenyatta National Hospital and the University of Washington. Results will be disseminated to clinicians at study sites and partner institutions, presented at conferences and published in peer-reviewed journals. The findings of this study could shift the paradigm for thinking about the mechanisms linking vaginal microbiota and prematurity by focusing attention on the preconception vaginal microbiota as a mediator of SPTB.

Butyrogenic bacteria after acute graft-versus-host disease (GVHD) are associated with the development of steroid-refractory GVHD

The presence of butyrogenic bacteria after the onset of acute GVHD associates with subsequent steroid-refractory GVHD or chronic GVHD. Butyrate inhibits human colonic stem cells from forming an intact epithelial monolayer.

Optimizing bacterial DNA extraction in urine

Urine is an acceptable, non-invasive sample for investigating the human urogenital microbiota and for the diagnosis of sexually transmitted infections. However, low quantities of bacterial DNA and PCR inhibitors in urine may prevent efficient PCR amplification for molecular detection of bacteria. Furthermore, cold temperatures used to preserve DNA and bacteria in urine can promote precipitation of crystals that interfere with DNA extraction. Saline, Dulbecco’s Phosphate Buffered Saline, or Tris-EDTA buffer were added to urine from adult men to determine if crystal precipitation could be reversed without heating samples beyond ambient temperature. Total bacterial DNA concentrations and PCR inhibition were measured using quantitative PCR assays to compare DNA yields with and without buffer addition. Dissolution of crystals with Tris-EDTA prior to urine centrifugation was most effective in increasing bacterial DNA recovery and reducing PCR inhibition. DNA recovery using Tris-EDTA was further tested by spiking urine with DNA from bacterial isolates and median concentrations of Lactobacillus jensenii and Escherichia coli 16S rRNA gene copies were found to be higher in urine processed with Tris-EDTA. Maximizing bacterial DNA yield from urine may facilitate more accurate assessment of bacterial populations and increase detection of specific bacteria in the genital tract.

Tenofovir disoproxil fumarate intravaginal ring for HIV pre-exposure prophylaxis in sexually active women: a phase 1, single-blind, randomised, controlled trial

BACKGROUND

An intravaginal ring that releases the tenofovir prodrug, tenofovir disoproxil fumarate, provided 100% protection in macaques against simian HIV and was safe in a 14-day clinical trial in sexually abstinent women. We aimed to assess the safety and pharmacokinetics of this intravaginal ring over 90 days in sexually active women.

METHODS

We did a phase 1, single-blind, randomised, placebo-controlled trial to assess safety, pharmacokinetics, and acceptability of a tenofovir disoproxil fumarate intravaginal ring used continuously with monthly ring changes for 3 months. Sexually active women who were HIV negative were randomly assigned (3:1) to a tenofovir disoproxil fumarate ring or placebo ring. Primary safety endpoint was the proportion of women who had grade 2 or higher genitourinary adverse events judged related to study product and any grade 2 or higher adverse event as defined by the Division of AIDS Table for Grading the Severity of Adult and Pediatric Adverse Events. We quantified tenofovir disoproxil fumarate and tenofovir concentrations in cervicovaginal fluid, tenofovir in plasma, and tenofovir diphosphate, the active metabolite, in cervical tissue and dried blood spots 1 month after each ring insertion. We compared changes over time in cervicovaginal fluid cytokine and chemokine concentrations and vaginal microbiota. The study was electively stopped early and is registered with ClinicalTrials.gov, number NCT02762617.

FINDINGS

Between Feb 24 and July 20, 2017, 17 women were enrolled before study termination. 12 were assigned to receive the tenofovir disoproxil fumarate ring and five were assigned to receive the placebo ring. Two participants in the tenofovir disoproxil fumarate ring group completed 3 months of continuous ring use; eight were asked to discontinue ring use early because of ulcerations (grade 1) near the ring; in the remaining two women, rings were electively removed by study staff on day 20 and day 23. Ulcers were detected a mean of 32 days after ring use (range 23-56). Four of eight participants with ulcers were symptomatic with vaginal discharge; four had ulcers identified when examined; three had two ulcers; all ulcers resolved after ring removal. No participants in the placebo group developed ulcers. No grade 2 product-related adverse events were reported in either group and four non-product-related grade 2 adverse events were reported in the tenofovir disoproxil fumarate ring group. Cervicovaginal fluid tenofovir concentrations did not differ at day 14 (p=0·14) comparing the eight patients who did (median 1·0 × 10⁵ ng/mL [IQR 9·1 × 10⁴-1·1 × 10⁵]) with the four who did not (6·0 × 10⁴ ng/mL [5·6 × 10⁴-1·1 × 10⁵]) develop ulcers. No significant changes in vaginal microbiota were detected in either group. Concentrations of multiple inflammatory cytokines and chemokines were significantly higher at days 14 and 28 compared with baseline in the tenofovir disoproxil fumarate ring group but not the placebo group.

INTERPRETATION

Future studies are needed to establish whether the unanticipated finding of ulcerations is specific to this tenofovir disoproxil fumarate ring or generalisable to other sustained topical release formulations of tenofovir or its prodrugs.

FUNDING

National Institutes of Health.

Associations between vaginal bacteria implicated in HIV acquisition risk and proinflammatory cytokines and chemokines

OBJECTIVES

Recent studies have identified vaginal bacterial taxa associated with increased HIV risk. A possible mechanism to explain these results is that individual taxa differentially promote cervicovaginal inflammation. This study aimed to explore relationships between concentrations of bacteria previously linked to HIV acquisition and vaginal concentrations of proinflammatory cytokines and chemokines.

METHODS

In this cross-sectional analysis, concentrations of 17 bacterial taxa and four proinflammatory cytokines (interleukin (IL)-1β, IL-6, IL-10 and tumour necrosis factor alpha (TNFα)) and two proinflammatory chemokines (IL-8 and interferon gamma-induced protein 10) were measured in vaginal swabs collected from 80 HIV-uninfected women. Cytokine and chemokine concentrations were compared between women with bacterial concentrations above or below the lower limit of detection as determined by quantitative PCR for each taxon. Principal component analysis was used to create a summary score for closely correlated bacteria, and linear regression analysis was used to evaluate associations between this score and increasing concentrations of TNFα and IL-1β.

RESULTS

Detection of Dialister micraerophilus (p=0.01), Eggerthella sp type 1 (p=0.05) or Mycoplasma hominis (p=0.03) was associated with higher TNFα concentrations, and detection of D. micraerophilus (p<0.01), Eggerthella sp type 1 (p=0.04), M. hominis (p=0.02) or Parvimonas sp type 2 (p=0.05) was associated with significantly higher IL-1β concentrations. Seven bacterial taxa (D. micraerophilus, Eggerthella sp type 1, Gemella asaccharolytica, Sneathia sp, Megasphaera sp, M. hominis and Parvimonas sp type 2) were found to be highly correlated by principal component analysis (eigenvalue 5.24, explaining 74.92% of variability). Linear regression analysis demonstrated associations between this principal component and concentrations of TNFα (β=0.55, 95% CI 0.01 to 1.08; p=0.048) and IL-1β (β=0.96, 95% CI 0.19 to 1.74; p=0.016).

CONCLUSIONS

This study provides evidence that several highly correlated vaginal bacterial taxa may influence vaginal cytokine and chemokine concentrations. These results suggest a mechanism where the presence of specific bacterial taxa could influence HIV susceptibility by increasing vaginal inflammation.

The gut microbiota and graft-versus-host disease

Graft-versus-host disease (GvHD) is a common complication of hematopoietic cell transplantation that negatively impacts quality of life in recipients and can be fatal. Animal experiments and human studies provide compelling evidence that the gut microbiota is associated with risk of GvHD, but the nature of this relationship remains unclear. If the gut microbiota is a driver of GvHD pathogenesis, then manipulation of the gut microbiota offers one promising avenue for preventing or treating this common condition, and antibiotic stewardship efforts in transplantation may help preserve the indigenous microbiota and modulate immune responses to benefit the host.

The Evolving Facets of Bacterial Vaginosis: Implications for HIV Transmission

Bacterial vaginosis (BV) is a common yet poorly understood vaginal condition that has become a major focus of HIV transmission and immunology research. Varied terminologies are used by clinicians and researchers to describe microbial communities that reside in the female reproductive tract (FRT), which is driven, in part, by microbial genetic and metabolic complexity, evolving diagnostic and molecular techniques, and multidisciplinary perspectives of clinicians, epidemiologists, microbiologists, and immunologists who all appreciate the scientific importance of understanding mechanisms that underlie BV. This Perspectives article aims to clarify the varied terms used to describe the cervicovaginal microbiota and its “nonoptimal” state, under the overarching term of BV. The ultimate goal is to move toward language standardization in future literature that facilitates a better understanding of the impact of BV on FRT immunology and risk of sexually transmitted infections, including HIV.

Association between vaginal washing and detection of Lactobacillus by culture and quantitative PCR in HIV-seronegative Kenyan women: a cross-sectional analysis

OBJECTIVES

Vaginal washing has been associated with reductions in cultivable Lactobacillus and an increased risk of both bacterial vaginosis (BV) and HIV infection. The effect of vaginal washing on the quantity of individual Lactobacillus species is not well characterised. This analysis tested the hypothesis that vaginal washing would be associated with a lower likelihood of Lactobacillus spp. detected by both culture and quantitative PCR (qPCR).

METHODS

We conducted a cross-sectional study of 272 HIV-seronegative women enrolled in an open-cohort study in Mombasa, Kenya. Vaginal washing and sexual risk behaviours were assessed using face-to-face interviews. Vaginal Lactobacillus spp. were detected using cultivation and PCR methods, with L. crispatus, L. jensenii and L. iners concentrations measured using qPCR assays targeting the 16S rRNA gene. Poisson regression with robust SEs was used to assess associations between vaginal washing and Lactobacillus detection by culture and qPCR.

RESULTS

Eighty percent (n=217) of participants reported vaginal washing in the prior week. One-fifth (n=58) of participants had BV by Nugent score. In unadjusted analysis, vaginal washing was associated with a 45% decreased likelihood of Lactobacillus spp. detection by culture (prevalence ratio (PR): 0.55, 95% CI 0.37 to 0.82). Adjusting for age and condomless sex in the prior week did not change the magnitude of the association (adjusted PR (aPR): 0.56, 95% CI (0.37 to 0.85). Vaginal washing was associated with approximately a 40% reduction in L. crispatus detection (aPR: 0.57, 95% CI 0.36 to 0.92), but was not significantly associated with L. jensenii (aPR: 0.68, 95% CI 0.42 to 1.09) or L. iners detection (aPR: 1.03, 95% CI 0.92 to 1.15).

CONCLUSIONS

Vaginal washing in the prior week was associated with a significantly reduced likelihood of detecting cultivable Lactobacillus and L. crispatus by qPCR. Given associations between Lactobacillus detection and improved reproductive health outcomes, these results provide motivation for additional study of vaginal washing cessation interventions to improve vaginal health.

Association between vaginal washing and vaginal bacterial concentrations

Vaginal washing is a common practice associated with adverse outcomes including bacterial vaginosis (BV) and HIV infection. Prior studies have not examined the associations between vaginal washing and individual vaginal bacteria, or whether these associations are independent of the effect of vaginal washing on BV. The purpose of this study was to characterize the association between vaginal washing and the presence and concentrations of vaginal bacteria associated with optimal and sub-optimal vaginal states. The analysis utilized data from participants in the placebo arm of the Preventing Vaginal Infections trial, which enrolled HIV-uninfected women from the United States and Kenya. Detection of bacterial taxa associated with BV was compared between visits with versus without reported vaginal washing. The effect of vaginal washing on a number of vaginal bacteria differed substantially (p<0.05) between the US and Kenya, so results were stratified by country. In US women, vaginal washing was associated with a significantly higher likelihood of detection of BV associated bacterium 1 (BVAB1) (relative risk [RR] 1.55, 95% confidence interval [CI] 1.15-2.09, p = 0.004), BVAB2 (RR 1.99, 95%CI 1.46-2.71, p<0.001), Mageeibacillus indolicus (RR 2.08, 95%CI 1.46-2.96, p<0.001), Atopobium vaginae (RR 1.34, 95%CI 1.13-1.59, p = 0.001), Leptotrichia/Sneathia species (RR 1.66, 95% CI 1.33-2.09, p<0.001), Megasphaera species (RR 1.78, 95%CI 1.34-2.37, p<0.001) and Gardnerella vaginalis (RR 1.08, 95%CI 1.01-1.16, p = 0.02). No significant association between vaginal washing and bacterial detection was found in Kenyan women. Adjustment for bacterial vaginosis diagnosed by Gram stain did not alter these results. This study provides evidence that the association between vaginal washing and detection of individual bacterial taxa can vary regionally. For some vaginal bacteria, the association with vaginal washing may be independent of the effect on Gram stain detection of BV. Larger prospective studies in diverse geographic settings should explore whether eliminating vaginal washing impacts the presence and concentrations of key vaginal bacteria.

Cross-sectional study of urethral exposures at last sexual episode associated with non-gonococcal urethritis among STD clinic patients

OBJECTIVE

Although Chlamydia trachomatis (CT) and Mycoplasma genitalium (MG) are major causes of non-gonococcal urethritis (NGU), up to 50% of cases are of unknown aetiology. We sought to identify urethral exposures at last sexual episode associated with NGU and non-CT/non-MG NGU to identify anatomical sites from which aetiologically relevant micro-organisms may be acquired.

METHODS

We enrolled STD clinic patients with and without NGU assigned male sex at birth and age ≥16 into a cross-sectional study. NGU was urethral symptoms or visible discharge plus ≥5 polymorphonuclear leucocytes without Neisseria gonorrhoeae. Urine was tested for CT and MG (Aptima). We used logistic regression to estimate the association between urethral exposures at last sex and NGU separately among cisgender men and transgender women who have sex with men (MSM/TGWSM) and cisgender men who have sex with women (MSW).

RESULTS

Between 8 August 2014 and 1 November 2017, we enrolled 432 patients, including 183 MSM/TGWSM (118 NGU+, 65 NGU-) and 249 MSW (126 NGU+, 123 NGU-). The mean age was 34; 59% were white. CT and MG were detected in 72 (30%) and 49 (20%) NGU+ participants, respectively. Compared with MSM/TGWSM reporting only non-urethral exposures at last sex, those reporting insertive anal intercourse (IAI) only (adjusted OR (AOR)=4.46, 95% CI 1.09 to 18.19) and IAI with insertive oral sex (IOS) (AOR=7.88, 95% CI 2.67 to 23.26) had higher odds of NGU. MSM/TGWSM reporting IOS only had no significant increased odds (AOR=1.67, 95% CI 0.58 to 4.85). Compared with MSW whose only urethral exposure at last sex was vaginal sex (VS), MSW reporting IOS and VS had similar odds of NGU (OR=0.84, 95% CI 0.50 to 1.41). The results were similar for non-CT/non-MG NGU.

CONCLUSIONS

Among MSM/TGWSM, IAI may lead to transmission of yet-unidentified rectal micro-organisms that cause non-CT/non-MG NGU, in addition to transmission of known pathogens. Sites of urethral exposure appear less important for understanding NGU risk among MSW due to minimal variation in behaviour.