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 6 validly named species and several genomospecies. We hypothesized that particular Gardnerella species may be more associated with BV. METHODS: Quantitative polymerase chain reaction (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 3 or more Gardnerella species groups detected compared to 32.0% of BV-negative participants (P < .0001). BV-negative participants with 3 or more species groups detected were more likely to develop BV within 100 days versus those with fewer (60.5% vs 3.7%, P < .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.

Vaginal microbiome community state types and high-risk human papillomaviruses in cervical precancer and cancer in North-central Nigeria.

BACKGROUND: High risk human papillomaviruses (HR-HPV) have a causal role in cervical oncogenesis, and HIV-mediated immune suppression allows HR-HPV to persist. We studied whether vaginal microbiome community state types (CSTs) are associated with high-grade precancer and/or invasive cervical cancer (HSIL/ICC). METHODS: This was a cross-sectional study of adult women with cervical cancer screening (CCS) at the Jos University Teaching Hospital (JUTH) in Jos, Nigeria, between January 2020 and February 2022. Cervical swabs underwent HPV genotyping (Anyplex™ II HPV28). Cervico-vaginal lavage (CVL) sample was collected for 16 S rRNA gene amplicon sequencing. We used multivariable logistic regression modelling to assess associations between CSTs and other factors associated with HSIL/ICC. RESULTS: We enrolled 155 eligible participants, 151 with microbiome data for this analysis. Women were median age 52 (IQR:43-58), 47.7% HIV positive, and 58.1% with HSIL/ICC. Of the 138 with HPV data, 40.6% were negative for HPV, 10.1% had low-risk HPV, 26.8% had single HR-HPV, and 22.5% had multiple HR-HPV types. The overall prevalence of any HR-HPV type (single and multiple) was 49.3%, with a higher proportion in women with HSIL/ICC (NILM 31.6%, LSIL 46.5%, HSIL 40.8%, and 81.5% ICC; p = 0.007). Women with HIV were more likely to have HSIL/ICC (70.3% vs. 29.7% among women without HIV). In crude and multivariable analysis CST was not associated with cervical pathology (CST-III aOR = 1.13, CST-IV aOR = 1.31). However, in the presence of HR-HPV CST-III (aOR = 6.7) and CST-IV (aOR = 3.6) showed positive association with HSIL/ICC. CONCLUSION: Vaginal microbiome CSTs were not significantly associated with HSIL/ICC. Our findings suggest however, that CST could be helpful in identifying women with HSIL/ICC and particularly those with HR-HPV. Characterization of CSTs using point-of-care molecular testing in women with HR-HPV should be studied as an approach to improve early detection and cervical cancer prevention. Future longitudinal research will improve our understanding of the temporal effect of non-optimal CST, HR-HPV, and other factors in cervical cancer development, prevention, and control.

Characterization of an α-Glucosidase Enzyme Conserved in Gardnerella spp. Isolated from the Human Vaginal Microbiome.

Gardnerella spp. in the vaginal microbiome are associated with bacterial vaginosis, in which a lactobacillus-dominated community is replaced with mixed bacteria, including Gardnerella species. Co-occurrence of multiple Gardnerella species in the vaginal environment is common, but different species are dominant in different women. Competition for nutrients, including glycogen, could play an important role in determining the microbial community structure. Digestion of glycogen into products that can be taken up and further processed by bacteria requires the combined activities of several enzymes collectively known as amylases, which belong to glycoside hydrolase family 13 (GH13) within the CAZy classification system. GH13 is a large and diverse family of proteins, making prediction of their activities challenging. SACCHARIS annotation of the GH13 family in Gardnerella resulted in identification of protein domains belonging to eight subfamilies. Phylogenetic analysis of predicted amylase sequences from 26 genomes demonstrated that a putative α-glucosidase-encoding sequence, CG400_06090, was conserved in all Gardnerella spp. The predicted α-glucosidase enzyme was expressed, purified, and functionally characterized. The enzyme was active on a variety of maltooligosaccharides with maximum activity at pH 7. Km, kcat, and kcat/Km values for the substrate 4-nitrophenyl α-d-glucopyranoside were 8.3 µM, 0.96 min-1, and 0.11 µM-1 min-1, respectively. Glucose was released from maltose, maltotriose, maltotetraose, and maltopentaose, but no products were detected when the enzyme was incubated with glycogen. Our findings show that Gardnerella spp. produce an α-glucosidase enzyme that may contribute to the multistep process of glycogen metabolism by releasing glucose from maltooligosaccharides. IMPORTANCE Increased abundance of Gardnerella spp. is a diagnostic characteristic of bacterial vaginosis, an imbalance in the human vaginal microbiome associated with troubling symptoms, and negative reproductive health outcomes, including increased transmission of sexually transmitted infections and preterm birth. Competition for nutrients is likely an important factor in causing dramatic shifts in the vaginal microbial community but little is known about the contribution of bacterial enzymes to the metabolism of glycogen, a major carbon source available to vaginal bacteria. The significance of our research is characterizing the activity of an enzyme conserved in Gardnerella species that likely contributes to the ability of these bacteria to utilize glycogen.

Rapid differential diagnosis of vaginal infections using gold nanoparticles coated with specific antibodies.

Vaginal infections caused by bacteria, Candida and Trichomonas vaginalis, affect millions of women annually worldwide. Symptoms and signs have limited value in differential diagnosis of three causes of vaginitis. Current laboratory methods for differential diagnosis are either expensive or time consuming. Therefore, in this work, development of a method based on gold nanoparticles has been investigated for rapid diagnosis of vaginal infections. Specific antibodies against three main causes of vaginal infections were raised in rabbits. The antibodies were then purified and conjugated to gold nanoparticles and used in an agglutination test for detection of vaginal infections. Finally, sensitivity and specificity of this test for diagnosis of vaginal infections were estimated using culture method as gold standard. Purification of antibodies from sera was confirmed by electrophoresis. Construction of nanoparticles was proved by TEM and FT-IR methods. Conjugation of antibodies to gold nanoparticles was confirmed using XPS method. Sensitivity and specificity of gold nanoparticles for diagnosis of Candida species were 100%, for Gardnerella were 100% and 93%, and for T. vaginalis was 53.3% and 100%, respectively. Gold nanoparticle-based method is a simple, rapid, accurate, and cost-effective test for differential laboratory diagnosis of vaginal infections.

Not Your Garden-Variety Bacteremia: Gardnerella in an Immunocompromised Man.

Systemic Gardnerella infections are rare and usually associated with surgical instrumentation of the genitourinary tract. We present a case of symptomatic and transient Gardnerella bacteremia in a man with AIDS after a traumatic urinary catheter insertion.

The female urinary microbiome in urgency urinary incontinence.

OBJECTIVE: The purpose of this study was to characterize the urinary microbiota in women who are planning treatment for urgency urinary incontinence and to describe clinical associations with urinary symptoms, urinary tract infection, and treatment outcomes. STUDY DESIGN: Catheterized urine samples were collected from multisite randomized trial participants who had no clinical evidence of urinary tract infection; 16S ribosomal RNA gene sequencing was used to dichotomize participants as either DNA sequence-positive or sequence-negative. Associations with demographics, urinary symptoms, urinary tract infection risk, and treatment outcomes were determined. In sequence-positive samples, microbiotas were characterized on the basis of their dominant microorganisms. RESULTS: More than one-half (51.1%; 93/182) of the participants' urine samples were sequence-positive. Sequence-positive participants were younger (55.8 vs 61.3 years old; P = .0007), had a higher body mass index (33.7 vs 30.1 kg/m(2); P = .0009), had a higher mean baseline daily urgency urinary incontinence episodes (5.7 vs 4.2 episodes; P < .0001), responded better to treatment (decrease in urgency urinary incontinence episodes, -4.4 vs -3.3; P = .0013), and were less likely to experience urinary tract infection (9% vs 27%; P = .0011). In sequence-positive samples, 8 major bacterial clusters were identified; 7 clusters were dominated not only by a single genus, most commonly Lactobacillus (45%) or Gardnerella (17%), but also by other taxa (25%). The remaining cluster had no dominant genus (13%). CONCLUSION: DNA sequencing confirmed urinary bacterial DNA in many women with urgency urinary incontinence who had no signs of infection. Sequence status was associated with baseline urgency urinary incontinence episodes, treatment response, and posttreatment urinary tract infection risk.

Intra-uterine microbial colonization and occurrence of endometritis in women with endometriosis†.

STUDY QUESTION: Is there any risk of intra-uterine bacterial colonization and concurrent occurrence of endometritis in women with endometriosis? SUMMARY ANSWER: An increase in intra-uterine microbial colonization and concurrent endometritis occurred in women with endometriosis that was further increased after GnRH agonist (GnRHa) treatment. WHAT IS KNOWN ALREADY: Higher bacterial contamination of menstrual blood and increased endotoxin level in menstrual and peritoneal fluids have been found in women with endometriosis than in control women. However, information on intra-uterine microbial colonization across the phases of the menstrual cycle and possible occurrence of endometritis in women with endometriosis is still lacking. STUDY DESIGN, SIZE AND DURATION: This is a case-controlled study with prospective collection of vaginal smears/endometrial samples from women with and without endometriosis and retrospective evaluation. PARTICIPANTS/MATERIALS, SETTING, METHODS: Vaginal smears and endometrial smears were collected from 73 women with endometriosis and 55 control women. Twenty of the women with endometriosis and 19 controls had received GnRHa therapy for a period of 4-6 months. Vaginal pH was measured by intra-vaginal insertion of a pH paper strip. The bacterial vaginosis (BV) score was analyzed by Gram-staining of vaginal smears and based on a modified Nugent-BV scoring system. A panel of bacteria was analyzed by culture of endometrial samples from women treated with GnRHa or not treated. Immunohistochemcial analysis was performed using antibody against Syndecan-1 (CD138) and myeloperoxidase in endometrial biopsy specimens from women with and without endometriosis. MAIN RESULTS AND THE ROLE OF CHANCE: A significant shifting of intra-vaginal pH to ≥4.5 was observed in women with endometriosis compared with control women (79.3 versus 58.4%, P < 0.03). Compared with untreated women, use of GnRHa therapy also shifted vaginal pH to ≥4.5 in both control women (P = 0.004) and in women with endometriosis (P = 0.03). A higher risk of increasing intermediate flora (total score, 4-6) (P = 0.05) was observed in women with endometriosis who had GnRHa treatment versus untreated women. The number of colony forming units (CFU/ml) of Gardnerella, α-Streptococcus, Enterococci and Escherichia coli was significantly higher in endometrial samples from women with endometriosis than control women (P < 0.05 for each bacteria). GnRHa-treated women also showed significantly higher colony formation for some of these bacteria in endometrial samples than in untreated women (Gardnerella and E. coli for controls; Gardnerella, Enterococci and E. coli for women with endometriosis, P < 0.05 for all). Although there was no significant difference in the occurrence of acute endometritis between women with and without endometriosis, both GnRHa-treated controls and women with endometriosis had a significantly higher occurrence of acute endometritis (P = 0.003 for controls, P = 0.001 for endometriosis versus untreated women). Multiple analysis of covariance analysis revealed that an intra-vaginal pH of ≥4.5 (P = 0.03) and use of GnRHa (P = 0.04) were potential factors that were significantly and independently associated with intra-uterine microbial colonization and occurrence of endometritis in women with endometriosis. These findings indicated the occurrence of sub-clinical uterine infection and endometritis in women with endometriosis after GnRHa treatment. LIMITATIONS, REASONS FOR CAUTION: We cannot exclude the introduction of bias from unknown previous treatment with immunosuppressing or anti-microbial agents. We have studied a limited range of bacterial species and used only culture-based methods. More sensitive molecular approaches would further delineate the similarities/differences between the vaginal cavity and uterine environment. WIDER IMPLICATIONS OF THE FINDINGS: Our current findings may have epidemiological and biological implications and help in understanding the pathogenesis of endometriosis and related disease burden. The worsening of intra-uterine microbial colonization and higher occurrence of endometritis in women with endometriosis who were treated with GnRHa identifies some future therapeutic avenues for the management, as well as prevention of recurrence, of endometriosis. Further studies are needed to examine intra-uterine colonization of a broad range of common bacteria as well as different viruses and their role in the occurrence of endometritis. STUDY FUNDING/COMPETING INTERESTS: This work was supported by Grants-in-Aid for Scientific Research from the Ministry of Education, Sports, Culture, Science and Technology of Japan. There is no conflict of interest related to this study. TRIAL REGISTRATION NUMBER: Not applicable.

Gardnerella diversity and ecology in pregnancy and preterm birth.

The vaginal microbiome has been linked to negative health outcomes including preterm birth. Specific taxa, including Gardnerella spp., have been identified as risk factors for these conditions. Historically, microbiome analysis methods have treated all Gardnerella spp. as one species, but the broad diversity of Gardnerella has become more apparent. We explore the diversity of Gardnerella clades and genomic species in the vaginal microbiome of pregnant women and their associations with microbiome composition and preterm birth. Relative abundance of Gardnerella clades and genomic species and other taxa was quantified in shotgun metagenomic sequencing data from three distinct cohorts of pregnant women. We also assessed the diversity and abundance of Gardnerella variants in 16S rRNA gene amplicon sequencing data from seven previously conducted studies in differing populations. Individual microbiomes often contained multiple Gardnerella variants, and the number of clades was associated with increased microbial load, or the ratio of non-human reads to human reads. Taxon co-occurrence patterns were largely consistent across Gardnerella clades and among cohorts. Some variants previously described as rare were prevalent in other cohorts, highlighting the importance of surveying a diverse set of populations to fully capture the diversity of Gardnerella. The diversity of Gardnerella both across populations and within individual vaginal microbiomes has long been unappreciated, as has been the intra-species diversity of many other members of the vaginal microbiome. The broad genomic diversity of Gardnerella has led to its reclassification as multiple species; here we demonstrate the diversity of Gardnerella found within and between vaginal microbiomes.IMPORTANCEThe present study shows that single microbiomes can contain all currently known species of Gardnerella and that multiple similar species can exist within the same environment. Furthermore, surveys of demographically distinct populations suggest that some species appear more commonly in certain populations. Further studies in broad and diverse populations will be necessary to fully understand the ecological roles of each Gardnerella sp., how they can co-exist, and their distinct impacts on microbial communities, preterm birth, and other health outcomes.

Candida albicans and bacterial vaginosis can coexist on Pap smears.

OBJECTIVE: The aim of our study was to study the relationship of blastospores and pseudohyphae in Papanicolaou (Pap) smears and Nugent scores for bacterial vaginosis (BV). STUDY DESIGN: A total of 471 Pap smears with Candida albicans were reviewed. The presence of blastospores and pseudohyphae was established. The Pap smears were restained with the Gram stain method to evaluate the bacterial flora according to the Nugent scoring system. RESULTS: Of the 471 Pap smears, blastospores and pseudohyphae were observed in 62.8% (296/471) and 37.2% (175/471) of the smears, and displayed symptoms in 4.4% (13/296) and 43.4% (76/175), respectively. A significant difference was found between these 2 groups (p < 0.0001). A positive BV Nugent score (≥ 7) was found in 22.1% (104/471) of the C. albicans cases. Blastospores and pseudohyphae with BV were 14.2% (42/296) and 35.4% (62/175), respectively. These high Nugent scores indicate statistically significant differences (p < 0.0001). CONCLUSION: C. albicans and BV can coexist. The presence of blastospores in these C. albicans cases was negatively related to symptoms.

Gardnerella, Trichomonas vaginalis, Candida, Chlamydia trachomatis, Mycoplasma hominis and Ureaplasma urealyticum in the genital discharge of symptomatic fertile and asymptomatic infertile women.

This study aimed to establish the different prevalence of the microorganisms investigated in the two groups considered: fertile women with symptoms and asymptomatic women with infertility problems. The data from women (n= 952) investigated for two years for quality of genital discharge and the presence of Gardnerella vaginalis, Trichomonas vaginalis, Candida species, Streptococcus agalactiae, Mycoplasma hominis, Ureaplasma urealyiticum and Chlamydia trachomatis were retrospectively analyzed. In the population of fertile women with symptoms the microrganisms most frequently involved are Gardnerella vaginalis (26.6%), Candida species (12.1%) and Streptococcus agalactiae (9.2%). The genital discharges of asymptomatic women with infertility problems are characterized by a prevalence of Gardnerella vaginalis (19.7%), Enterobacteriaceae or Enterococci (12.1%) and Streptococcus agalactiae (8.6%). The reduction of vaginal lactobacilli flora and the presence of an elevated number of polymorphonucleates in the vaginal discharge are important parameters to consider for the evaluation of the health status of the human female urogenital tract. Our results indicate that is important to culture the vaginal discharge for Streptococcus agalactiae and for prevalence of Enterobacteriaceae and Enterococci. Lastly, the reasons for the prevalence of some microorganisms (Gardnerella vaginalis, Enterobacteriaceae and Enterococci, Streptococcus agalactiae) in the population of infertile asymptomatic women need to be better analyzed especially after the recent studies correlating idiopathic infertility with the presence of cervical cytokines in women with an abnormal vaginal flora.

Characteristics of the microbiota in the urine of women with type 2 diabetes.

PURPOSE: The urinary microbiota in women with type 2 diabetes (T2DM) can have bacterial uropathogens which are more virulent. The primary objective was to describe and compare the characteristics of the microbiota in voided urine of women with and without T2DM. METHODS: Two cohorts of women: those with T2DM (n = 87) and those without T2DM (n = 49) were studied. Demographic data, hemoglobin A1c (HbA1c), fasting serum glucose, and voided urine were collected. To determine the characteristics of the microbiota in the urine, 16S rRNA gene sequencing was used. RESULTS: The genus Lactobacillus was more often present in women with T2DM (75.9%, n = 66) than in the controls (59.2%, n = 30) (p = 0.042), as was the family Enterobacteriaceae (12.6% T2DM versus 2.0% control, p = 0.055). There was evidence of an association between HbA1c and the relative abundance of the various bacteria in the total cohort. The relative abundance of Lactobacillus was positively associated (ρ = 0.19, 95% CI: 0.02, 0.34), while Corynebacterium (ρ = -0.26, 95% CI: -0.41, -0.10) and Prevotella (ρ = -0.23, 95% CI: -0.38, -0.06) were inversely associated with HbA1c. CONCLUSIONS: Enterobacteriaceae (e.g. E. coli) predispose women to urinary tract infections and since T2DM increases this risk, further study is needed. The species of Lactobacillus and its impact needs exploration.

Growth Forms of Gardnerella spp. and Lactobacillus spp. on Vaginal Cells.

Bacterial vaginosis (BV) is a common vaginal condition in women of reproductive age. During BV development, BV-associated bacteria may form a polymicrobial biofilm, which predispose women to recurrent BV. The aim of the study was to investigate the growth forms of Gardnerella spp. and Lactobacillus spp. and to determine the association between the bacterial growth forms and clinical characteristics [urinary tract infection (UTI) symptoms, human immunodeficiency virus (HIV) infection and abnormal vaginal discharge] in women attending a tertiary hospital in Pretoria, South Africa. A first-void urine specimen was collected from 196 women and BV was diagnosed using the Nugent scoring and the Ison-Hay criteria (vaginal smear microscopy). Fluorescence in situ hybridisation (FISH) was performed to classify the growth forms ["dispersed" or "biofilm"]. Bacterial cells were categorized as "dispersed" if cells were scattered separately and as "biofilm" if bacterial aggregates on the vaginal epithelial cells were observed. BV was detected in 52 women (52/196; 27%) and in these women, Gardnerella spp. were predominantly present in biofilms (46/52; 88% for Nugent scoring; and 45/50; 90% for Ison-Hay criteria), whereas Lactobacillus spp. were predominantly present in a dispersed form (38/52; 73% for Nugent scoring; and 37/50; 74% for Ison-Hay criteria). The odds of having BV increased when Gardnerella biofilms were present (p < 0.001), whereas the opposite was observed for Lactobacillus biofilms (p = 0.001). Neither Gardnerella spp. or Lactobacillus spp. (both dispersed or biofilms) had an association with the presence of UTI symptoms, HIV coinfection or abnormal vaginal discharge. In conclusion, this study demonstrated and confirmed that Gardnerella biofilms are associated with BV and that Lactobacillus spp. may form biofilms to protect against BV.

Recurrent bacterial vaginosis.

PURPOSE OF REVIEW: Bacterial vaginosis is a common condition that recurs frequently, adversely affecting women's lives, and is associated with complications including increased risk of sexually transmitted infections, HIV, and adverse pregnancy outcome. RECENT FINDINGS: New molecular techniques have increased our understanding of the numerous bacteria associated with bacterial vaginosis, and a biofilm containing mostly Gardnerella and Atopobium vaginae, which can persist after treatment has been described. Suppressive treatment with metronidazole gel can suppress recurrence. Physiological approaches such as acidification and probiotics have been investigated with variable results. SUMMARY: Advances in our understanding of the pathogenesis of bacterial vaginosis allow the opportunity to improve treatments to prevent recurrence, which may require a combination of modalities. We must find ways to help affected women and reduce the complications associated with bacterial vaginosis.

[Vaginal microflora and relevant factors in puerperium].

OBJECTIVE: To find out the bacterial species in the vagina of postpartum women and the possible influencing factors on colonization. METHODS: From Jun. 2007 to Oct. 2007, 560 postpartum women from 7 hospitals in China were enrolled. Questionnaire survey, gynecological examination and Nugent score of vaginal smear and microbial spectrum study of the vaginal flora were completed. RESULTS: (1) According to the Nugent score, 48 out of the 560 women were normal (8.6%), 337 at the borderline (60.2%) and 175 (31.2%) were complicated with bacterial vaginosis (BV). Among the 560 women, Bacterium lacticum were identified in 74 cases (13.2%), but not in the rest 486 cases (86.8%). Gardnerella and bacteroids were detected in 322 women (57.5%) and small flectobacillus in 214 women (38.2%) out of the 560 subjects. (2) Influencing factors on vaginal microflora: among the 266 women who had normal vaginal delivery, 25 (9.4%) showed normal vaginal microflora, 148 (55.6%) at borderline and BV was diagnosed in 93 women (35.0%). The corresponding figures among the 294 women who underwent cesarean section were 23 (7.8%), 189 (64.3%) and 82 (27.9%), respectively. However, the incidence of BV had no statistical difference between these two groups (P = 0.204). In the 233 women who received episiotomy, 22 (9.4%) showed normal vaginal microflora, 135 (57.9%) at borderline and 76 presented with BV (32.6%), the corresponding figures among the 327 women without episiotomy were 26 (8.0%), 202 (61.8%) and 99 (30.2%), respectively. The incidence of BV did not show any statistical difference between the above two groups (P = 0.790). (3) Prenatal vaginitis were reported in 46 women, among which 5 (10.9%) with normal vaginal flora, 26 (56.5%) at borderline and 15 (32.6%) with BV, and again in the 514 women without prenatal vaginits, the above figures changed to 43 (8.4%), 311 (60.5%) and 160 (31.1%). No significant difference was found in the incidence of BV between the two groups (P = 0.962). The rate of BV in women without sex, with sex occasionally and with sex frequently during pregnancy was 27.5% (78/284), 35.6% (96/270) and 1/6, respectively (P = 0.185), and the numbers in women who had breast-feeding, bottle feeding and mixed feeding were 31.0% (67/216), 39.3% (35/89) and 28.6% (73/255), respectively (P = 0.573). CONCLUSIONS: The amount of Lactobacillus in vagina of postpartum women is greatly reduced leading to dysbacteria. The incidence of BV is not affected by vaginal delivery, episiotomy, vaginitis, prenatal intercourse and the way of feeding, but is higher in postpartum women.

A novel sequencing-based vaginal health assay combining self-sampling, HPV detection and genotyping, STI detection, and vaginal microbiome analysis.

The composition of the vaginal microbiome, including both the presence of pathogens involved in sexually transmitted infections (STI) as well as commensal microbiota, has been shown to have important associations for a woman's reproductive and general health. Currently, healthcare providers cannot offer comprehensive vaginal microbiome screening, but are limited to the detection of individual pathogens, such as high-risk human papillomavirus (hrHPV), the predominant cause of cervical cancer. There is no single test on the market that combines HPV, STI, and microbiome screening. Here, we describe a novel inclusive vaginal health assay that combines self-sampling with sequencing-based HPV detection and genotyping, vaginal microbiome analysis, and STI-associated pathogen detection. The assay includes genotyping and detection of 14 hrHPV types, 5 low-risk HPV types (lrHPV), as well as the relative abundance of 31 bacterial taxa of clinical importance, including Lactobacillus, Sneathia, Gardnerella, and 3 pathogens involved in STI, with high sensitivity, specificity, and reproducibility. For each of these taxa, reference ranges were determined in a group of 50 self-reported healthy women. The HPV sequencing portion of the test was evaluated against the digene High-Risk HPV HC2 DNA test. For hrHPV genotyping, agreement was 95.3% with a kappa of 0.804 (601 samples); after removal of samples in which the digene hrHPV probe showed cross-reactivity with lrHPV types, the sensitivity and specificity of the hrHPV genotyping assay were 94.5% and 96.6%, respectively, with a kappa of 0.841. For lrHPV genotyping, agreement was 93.9% with a kappa of 0.788 (148 samples), while sensitivity and specificity were 100% and 92.9%, respectively. This novel assay could be used to complement conventional cervical cancer screening, because its self-sampling format can expand access among women who would otherwise not participate, and because of its additional information about the composition of the vaginal microbiome and the presence of pathogens.

Cholesterol-Dependent Cytolysins Produced by Vaginal Bacteria: Certainties and Controversies.

Bacterial vaginosis (BV) is a vaginal anaerobic dysbiosis that affects women of reproductive age worldwide. BV is microbiologically characterized by the depletion of vaginal lactobacilli and the overgrowth of anaerobic bacterial species. Accumulated evidence suggests that Gardnerella spp. have a pivotal role among BV-associated bacteria in the initiation and development of BV. However, Gardnerella spp. often colonize healthy women. Lactobacillus iners is considered as a prevalent constituent of healthy vaginal microbiota, and is abundant in BV. Gardnerella spp. and L. iners secrete the toxins vaginolysin (VLY) and inerolysin (INY), which have structural and activity features attributed to cholesterol-dependent cytolysins (CDCs). CDCs are produced by many pathogenic bacteria as virulence factors that participate in various stages of disease progression by forming lytic and non-lytic pores in cell membranes or via pore-independent pathways. VLY is expressed in the majority of Gardnerella spp. isolates; less is known about the prevalence of the gene that encodes INY. INY is a classical CDC; membrane cholesterol acts a receptor for INY. VLY uses human CD59 as its receptor, although cholesterol remains indispensable for VLY pore-forming activity. INY-induced damage of artificial membranes is directly dependent on cholesterol concentration in the bilayer, whereas VLY-induced damage occurs with high levels of membrane cholesterol (>40 mol%). VLY primarily forms membrane-embedded complete rings in the synthetic bilayer, whereas INY forms arciform structures with smaller pore sizes. VLY activity is high at elevated pH, which is characteristic of BV, whereas INY activity is high at more acidic pH, which is specific for a healthy vagina. Increased VLY levels in vaginal mucosa in vivo were associated with clinical indicators of BV. However, experimental evidence is lacking for the specific roles of VLY and INY in BV. The interplay between vaginal bacterial species affects the expression of the gene encoding VLY, thereby modulating the virulence of Gardnerella spp. This review discusses the current evidence for VLY and INY cytolysins, including their structures and activities, factors affecting their expression, and their potential impacts on the progression of anaerobic dysbiosis.

Diversity of the midstream urine microbiome in adults with chronic kidney disease.

PURPOSE: To examine the characteristics of the midstream urine microbiome in adults with stage 3-5 non-dialysis-dependent chronic kidney disease (CKD). METHODS: Patients with non-dialysis-dependent CKD (estimated glomerular filtration rate [eGFR] < 60 ml/min/1.73 m2) and diuretic use were recruited from outpatient nephrology clinics. Midstream voided urine specimens were collected using the clean-catch method. The bacterial composition was determined by sequencing the hypervariable (V4) region of the bacterial 16S ribosomal RNA gene. Extraction negative controls (no urine) were included to assess the contribution of extraneous DNA from possible sources of contamination. Midstream urine microbiome diversity was assessed with the inverse Simpson, Chao and Shannon indices. The diversity measures were further examined by demographic characteristics and by comorbidities. RESULTS: The cohort of 41 women and 36 men with detectable bacterial DNA in their urine samples had a mean age of 71.5 years (standard deviation [SD] 7.9) years (range 60-91 years). The majority were white (68.0%) and a substantial minority were African-American (29.3%) The mean eGFR was 27.2 (SD 13.6) ml/min/1.73 m2. Most men (72.2%) were circumcised and 16.6% reported a remote history of prostate cancer. Many midstream voided urine specimens were dominated (> 50% reads) by the genera Corynebacterium (n = 11), Staphylococcus (n = 9), Streptococcus (n = 7), Lactobacillus (n = 7), Gardnerella (n = 7), Prevotella (n = 4), Escherichia_Shigella (n = 3), and Enterobacteriaceae (n = 2); the rest lacked a dominant genus. The samples had high levels of diversity, as measured by the inverse Simpson [7.24 (95% CI 6.76, 7.81)], Chao [558.24 (95% CI 381.70, 879.35)], and Shannon indices [2.60 (95% CI 2.51, 2.69)]. Diversity measures were generally higher in participants with urgency urinary incontinence and higher estimated glomerular filtration rate (eGFR). After controlling for demographics and diabetes status, microbiome diversity was significantly associated with estimated eGFR (P < 0.05). CONCLUSIONS: The midstream voided urine microbiome of older adults with stage 3-5 non-dialysis-dependent CKD is diverse. Greater microbiome diversity is associated with higher eGFR.

Effects of low dose estrogen therapy on the vaginal microbiomes of women with atrophic vaginitis.

Atrophic vaginitis (AV) is common in postmenopausal women, but its causes are not well understood. The symptoms, which include vaginal itching, burning, dryness, irritation, and dyspareunia, can usually be alleviated by low doses of estrogen given orally or locally. Regrettably, the composition of vaginal bacterial communities in women with AV have not been fully characterized and little is known as to how these communities change over time in response to hormonal therapy. In the present intervention study we determined the response of vaginal bacterial communities in postmenopausal women with AV to low-dose estrogen therapy. The changes in community composition in response to hormonal therapy were rapid and typified by significant increases in the relative abundance of Lactobacillus spp. that were mirrored by a decreased relative abundance of Gardnerella. These changes were paralleled by a significant four-fold increase in serum estradiol levels and decreased vaginal pH, as well as nearly a two-fold increase in the Vaginal Maturation Index (VMI). The results suggest that after menopause a vaginal microbiota dominated by species of Lactobacillus may have a beneficial role in the maintenance of health and these findings that could lead to new strategies to protect postmenopausal women from AV.

Reliability of interpretation of gram-stained vaginal smears by Nugent's scoring system for diagnosis of bacterial vaginosis.

This study was designed to assess reliability of interpretation of Gram-stained vaginal smears by using Nugent's scoring system for diagnosis of bacterial vaginosis (BV) across three different centers in Turkey: two in Ankara and one in Trabzon. The vaginal smears were collected from clients attending a family planning clinic in Trabzon, Turkey during October-December 1997. One slide taken from each client was prepared according to the standard methods and enumerated. One evaluator from each center examined the slides independently for the presence of BV and none of them had access to the evaluation of the others. Out of 372 slides, 301 (81%) were found to be satisfactory for scoring by all three evaluators and included in the analysis. Nugent's scores from 1-10 reported from each evaluator were compared by Spearman correlation coefficients and Kappa statistics. The difference in the proportions of BV diagnosis in three centers was evaluated by chi2 test. There was good agreement for the interpretation of Gram-stained vaginal smears by Nugent's scoring system for diagnosis of BV. These results indicate that it is a reliable method in diagnosis of BV at different settings.