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.

Vaginal Bacteria in Mares and the Occurrence of Antimicrobial Resistance

Antibiotics are added to semen extenders in insemination doses but their effect on the vaginal microbiota of the inseminated female is unknown. The objectives of this study were to define the equine vaginal microbiota and its antimicrobial resistance, and to determine whether it changes after exposure to antibiotics in semen extenders. Vaginal swabs were taken prior to sham-insemination (day 0), and again on days 3, 7, and 14 after insemination. Isolated bacteria were identified by MALDI-TOF and tested for antimicrobial susceptibility by microdilution. The bacteria isolated from the vagina differed according to reproductive status (brood mare or maiden mare), location (north or middle of Sweden), and the stage of the estrous cycle. Five bacterial species were frequently isolated from mares in both locations: Escherichia coli, Staphylococcus capitis, Streptococcus equisimilis, Streptococcus thoraltensis, and Streptococcus zooepidemicus. Overall, vaginal bacteria isolated from inseminated mares showed higher antibiotic resistance than from non-inseminated mares, suggesting a possible link between exposure to antibiotics in the semen extender and the appearance of antimicrobial resistance. The whole-genome sequencing of E. coli isolates from inseminated mares revealed some genes which are known to confer antimicrobial resistance; however, some instances of resistance in these isolates were not characteristic of induced AMR.

The structure and diversity of strain-level variation in vaginal bacteria

The vaginal microbiome plays an important role in human health and species of vaginal bacteria have been associated with reproductive disease. Strain-level variation is also thought to be important, but the diversity, structure and evolutionary history of vaginal strains is not as well characterized. We developed and validated an approach to measure strain variation from metagenomic data based on SNPs within the core genomes for six species of vaginal bacteria: Gardnerella vaginalis, Lactobacillus crispatus, Lactobacillus iners, Lactobacillus jensenii, Lactobacillus gasseri and Atopobium vaginae. Despite inhabiting the same environment, strain diversity and structure varies across species. All species except L. iners are characterized by multiple distinct groups of strains. Even so, strain diversity is lower in the Lactobacillus species, consistent with a more recent colonization of the human vaginal microbiome. Both strain diversity and the frequency of multi-strain samples is related to species-level diversity of the microbiome in which they occur, suggesting similar ecological factors influencing diversity within the vaginal niche. We conclude that the structure of strain-level variation provides both the motivation and means of testing whether strain-level differences contribute to the function and health consequences of the vaginal microbiome.

Maternal bacteria to correct abnormal gut microbiota in babies born by C-section

INTRODUCTION

There is evidence that caesarean section (CS) is associated with increased risk of childhood obesity, asthma, and coeliac disease. The gut microbiota of CS-born babies differs to those born vaginally, possibly due to reduced exposure to maternal vaginal bacteria during birth. Vaginal seeding is a currently unproven practice intended to reduce such differences, so that the gut microbiota of CS-born babies is similar to that of babies born vaginally. Our pilot study, which uses oral administration as a novel form of vaginal seeding, will assess the degree of maternal strain transfer and overall efficacy of the procedure for establishing normal gut microbiota development.

METHODS AND ANALYSIS

Protocol for a single-blinded, randomized, placebo-controlled pilot study of a previously untested method of vaginal seeding (oral administration) in 30 CS-born babies. A sample of maternal vaginal bacteria is obtained prior to CS, and mixed with 5 ml sterile water to obtain a supernatant. Healthy babies are randomized at 1:1 to receive active treatment (3 ml supernatant) or placebo (3 ml sterile water). A reference group of 15 non-randomized vaginal-born babies are also being recruited. Babies' stool samples will undergo whole metagenomic shotgun sequencing to identify potential differences in community structure between CS babies receiving active treatment compared to those receiving placebo at age 1 month (primary outcome). Secondary outcomes include differences in overall gut community between CS groups (24 hours, 3 months); similarity of CS-seeded and placebo gut profiles to vaginally-born babies (24 hours, 1 and 3 months); degree of maternal vaginal strain transfer in CS-born babies (24 hours, 1 and 3 months); anthropometry (1 and 3 months) and body composition (3 months).

ETHICS AND DISSEMINATION

Ethics approval by the Northern A Health and Disability Ethics Committee (18/NTA/49). Results will be published in peer-reviewed journals and presented at international conferences.

REGISTRATION

Australian New Zealand Clinical Trials Registry (ACTRN12618000339257).

A randomized trial of the bactericidal effects of chlorhexidine vs povidone-iodine vaginal preparation

BACKGROUND

Precesarean vaginal preparation significantly reduces postpartum infections. Although povidone-iodine is the most commonly used vaginal antiseptic, evidence suggests that chlorhexidine gluconate may be more effective.

OBJECTIVE

We aimed to compare the bactericidal effect of chlorhexidine gluconate and povidone-iodine on vaginal bacterial colony counts in pregnancy.

MATERIALS AND METHODS

We conducted a prospective randomized controlled trial of vaginal preparation with 0.5% chlorhexidine gluconate vs 10% povidone-iodine vs saline in women undergoing cesarean delivery at ≥34 weeks' gestation. Women in labor or those with ruptured membranes, chorioamnionitis, abnormal placentation, or allergy to study agents were excluded. Vaginal specimens were collected aseptically in the operating room immediately before and 5-10 minutes after vaginal cleansing with 3 sterile sponge sticks. Our primary outcome was postintervention aerobic and anaerobic bacterial colony counts, assessed by blinded investigators. Two-way analysis of variance with simple-effects analysis and Tukey post hoc test were used for multiple group comparisons. Secondary outcomes included baseline colony counts, change in colony counts, adverse events, and maternal infections.

RESULTS

A total of 29 women consented and underwent vaginal preparation with chlorhexidine gluconate (n=10), povidone-iodine (n=9), or saline (n=10). Groups were similar with respect to maternal age, body mass index, race, ethnicity, parity, group B streptococcus status, and gestational age. There were no differences in baseline colony counts. Vaginal preparation with povidone-iodine resulted in lower aerobic and anaerobic colony counts compared with chlorhexidine gluconate and saline (P≤.01 and P≤.0001, respectively). Povidone-iodine eliminated more than 99.9% of bacteria, whereas chlorhexidine gluconate and saline eliminated more than 99% and 95% of bacteria, respectively. Although all agents decreased aerobic and anaerobic bacterial counts, 0.5% chlorhexidine gluconate was no more effective than saline in reducing anaerobic bacteria. There were no reported adverse effects or postpartum infections.

CONCLUSION

Compared with 0.5% chlorhexidine gluconate, 10% povidone-iodine was more effective in reducing vaginal bacterial colony counts before cesarean delivery.

Evaluation of the inhibitory effects of vaginal microorganisms on sperm motility in vitro

Female infertility usually occurs as a result of ageing, physical impairment, hormone disturbances and lifestyle or environmental factors. However, the potential role of Lactobacillus in female infertility has remained largely unexplored. In the present study, high-throughput sequencing, real-time PCR, bacterial adherence assays and sperm motility assays were used to evaluate the microbial diversity, adherence properties and effect on sperm motility of sperm bacteria, vaginal bacteria and vaginal bacteria that had been co-cultured with sperm. The results indicated that in the co-culture group, Lactobacillus adhered to sperm cells in numbers that were 332-fold higher than those of control species Enterococcus and analysis of sequencing data using the Kyoto Encyclopedia of Genes and Genomes indicated that adhered microbes reduced sperm cell motility. Vaginal isolates, as well as bacterial strains used as controls, were co-cultured with sperm and it was indicated that all strains were able to adhere to sperm cells in large numbers. The probiotic Lactobacillus (L.) strains L. crispatus, L. acidophilus, L. helveticus and L. gasseri significantly reduced sperm motility (based on measurements of general, straightforward and non-straightforward progressive motility, total motility and average path velocity; P<0.05). Furthermore, L. crispatus, L. acidophilus, L. salivarius, L. helveticus and L. gasseri markedly reduced sperm penetration in a viscous medium. Based on these results, it may be hypothesized that the weakening effect of Lactobacillus on sperm motility may be beneficial for healthy couples to prevent the combination of abnormal sperms and eggs, but may be detrimental for males with severe asthenospermia, oligospermia or aspermia.

The association between vaginal bacterial composition and miscarriage: a nested case-control study

Objective

To characterise vaginal bacterial composition in early pregnancy and investigate its relationship with first and second trimester miscarriages.

Design

Nested case–control study.

Setting

Queen Charlotte’s and Chelsea Hospital, Imperial College Healthcare NHS Trust, London.

Population

161 pregnancies: 64 resulting in first trimester miscarriage, 14 in second trimester miscarriage and 83 term pregnancies.

Methods

Prospective profiling and comparison of vaginal bacteria composition using 16S rRNA gene‐based metataxonomics from 5 weeks’ gestation in pregnancies ending in miscarriage or uncomplicated term deliveries matched for age, gestation and body mass index.

Main outcome measures

Relative vaginal bacteria abundance, diversity and richness. Pregnancy outcomes defined as first or second trimester miscarriage, or uncomplicated term delivery.

Results

First trimester miscarriage associated with reduced prevalence of Lactobacillus spp.‐dominated vaginal microbiota classified using hierarchical clustering analysis (65.6 versus 87.7%; P = 0.005), higher alpha diversity (mean Inverse Simpson Index 2.5 [95% confidence interval 1.8–3.0] versus 1.5 [1.3–1.7], P = 0.003) and higher richness 25.1 (18.5–31.7) versus 16.7 (13.4–20), P = 0.017), compared with viable pregnancies. This was independent of vaginal bleeding and observable before first trimester miscarriage diagnosis (P = 0.015). Incomplete/complete miscarriage associated with higher proportions of Lactobacillus spp.‐depleted communities compared with missed miscarriage. Early pregnancy vaginal bacterial stability was similar between miscarriage and term pregnancies.

Conclusions

These findings associate the bacterial component of vaginal microbiota with first trimester miscarriage and indicate suboptimal community composition is established in early pregnancy. While further studies are required to elucidate the mechanism, vaginal bacterial composition may represent a modifiable risk factor for first trimester miscarriage.

Tweetable abstract

Vaginal bacterial composition in first trimester miscarriage is associated with reduced Lactobacillus spp. abundance and is independent of vaginal bleeding.

Vaginal bacterial composition in first trimester miscarriage is associated with reduced Lactobacillus spp. abundance and is independent of vaginal bleeding.