Effect of commercial vaginal products on the growth of uropathogenic and commensal vaginal bacteria.

Half of postmenopausal women experience genitourinary syndrome of menopause, for which many use lubricating vaginal products. The effect of vaginal products on uropathogenic and commensal vaginal bacteria is poorly understood. We evaluated the effect of five common vaginal products (KY Jelly, Replens Silky Smooth lubricant, coconut oil, Replens Long-Lasting moisturizer or Trimo-San) on growth and viability of Escherichia coli and Lactobacillus crispatus. Bacteria were co-cultured products alone and in the presence of both vaginal epithelial cells and selected products. Bacterial growth was compared between conditions using an unpaired t-test or ANOVA, as appropriate. All products except for coconut oil significantly inhibited growth of laboratory and clinical strains of Escherichia coli (p < 0.02). Only two products (Replens Long-Lasting moisturizer and Trimo-San) significantly inhibited growth of Lactobacillus crispatus (p < 0.01), while the product Replens Silky Smooth stimulated growth (p < 0.01). Co-culture of selected products in the presence of vaginal epithelial cells eliminated the inhibitory effects of the products on E. coli. In conclusion, in vitro exposure to vaginal moisturizing and lubricating products inhibited growth of Escherichia coli, though the inhibition was mitigated by the presence of vaginal epithelial cells. Lactobacillus crispatus demonstrated less growth inhibition than Escherichia coli.

Safety assessment of the candidate oral probiotic Lactobacillus crispatus YIT 12319: Analysis of antibiotic resistance and virulence-associated genes.

Lactobacillus crispatus YIT 12319 (LcY) was isolated from the oral cavity of a healthy subject as a new candidate probiotic with potential benefits for oral health. As a safety assessment of LcY, we performed an antibiotic susceptibility test and virulence-associated gene analysis using a draft genome sequence. Susceptibility to 15 antibiotics was analyzed according to the standard method of the International Dairy Federation/International Organization for Standardization, as recommended by the European Food Safety Authority. The results showed that the minimum inhibitory concentrations of LcY were not higher than those of other L. crispatus strains, which have not acquired resistance to any antibiotics, suggesting that LcY had no externally acquired transmissible antibiotic resistance genes. Analysis of virulence-associated genes using the draft genome of LcY found that there were fewer potential virulence-associated genes in LcY than in other probiotics. These findings suggest that LcY could be a candidate probiotic based on its safety profile.

Vaginal microbiome modulates topical antiretroviral drug pharmacokinetics.

Tenofovir gel and dapivirine ring provided variable HIV protection in clinical trials, reflecting poor adherence and possibly biological factors. We hypothesized that vaginal microbiota modulates pharmacokinetics and tested the effects of pH, individual bacteria, and vaginal swabs from women on pharmacokinetics and antiviral activity. Tenofovir, but not dapivirine, uptake by human cells was reduced as pH increased. Lactobacillus crispatus actively transported tenofovir leading to a loss in drug bioavailability and culture supernatants from Gardnerella vaginalis, but not Atopobium vaginae, blocked tenofovir endocytosis. The inhibition of endocytosis mapped to adenine. Adenine increased from 65.5 µM in broth to 246 µM in Gardnerella, but decreased to 9.5 µM in Atopobium supernatants. This translated into a decrease in anti-HIV activity when Gardnerella supernatants or adenine were added to cultures. Dapivirine was also impacted by microbiota, as drug bound irreversibly to bacteria, resulting in decreased antiviral activity. When drugs were incubated with vaginal swabs, 30.7% ± 5.7% of dapivirine and 63.9% ± 8.8% of tenofovir were recovered in supernatants after centrifugation of the bacterial cell pellet. In contrast, no impact of microbiota on the pharmacokinetics of the prodrugs, tenofovir disoproxil fumarate or tenofovir alafenamide, was observed. Together, these results demonstrate that microbiota may impact pharmacokinetics and contribute to inconsistent efficacy.

Treatment of biofilms in bacterial vaginosis by an amphoteric tenside pessary-clinical study and microbiota analysis.

BACKGROUND: Bacterial vaginosis (BV) is the most common vaginal syndrome among women in their reproductive years. It is associated with an increased risk of acquiring sexually transmitted infections and complications like preterm labor. BV is characterized by a high recurrence rate for which biofilms frequently found on vaginal epithelial cells may be a reason. RESULTS: Here, we report a controlled randomized clinical trial that tested the safety and effectiveness of a newly developed pessary containing an amphoteric tenside (WO3191) to disrupt biofilms after metronidazole treatment of BV. Pessaries containing lactic acid were provided to the control group, and microbial community composition was determined via Illumina sequencing of the V1-V2 region of the 16S rRNA gene. The most common community state type (CST) in healthy women was characterized by Lactobacillus crispatus. In BV, diversity was high with communities dominated by either Lactobacillus iners, Prevotella bivia, Sneathia amnii, or Prevotella amnii. Women with BV and proven biofilms had an increased abundance of Sneathia sanguinegens and a decreased abundance of Gardnerella vaginalis. Following metronidazole treatment, clinical symptoms cleared, Nugent score shifted to Lactobacillus dominance, biofilms disappeared, and diversity (Shannon index) was reduced in most women. Most of the patients responding to therapy exhibited a L. iners CST. Treatment with WO 3191 reduced biofilms but did not prevent recurrence. Women with high diversity after antibiotic treatment were more likely to develop recurrence. CONCLUSIONS: Stabilizing the low diversity healthy flora by promoting growth of health-associated Lactobacillus sp. such as L. crispatus may be beneficial for long-term female health. TRIAL REGISTRATION: ClinicalTrials.gov NCT02687789.

Layer-by-Layer Engineered Microbicide Drug Delivery System Targeting HIV-1 gp120: Physicochemical and Biological Properties.

The purpose of this study was to engineer a model anti-HIV microbicide (tenofovir) drug delivery system targeting HIV-1 envelope glycoprotein gp120 (HIV-1 g120) for the prevention of HIV sexual transmission. HIV-1 g120 and mannose responsive particles (MRP) were prepared through the layer-by-layer coating of calcium carbonate (CaCO3) with concanavalin A (Con A) and glycogen. MRP average particle size ranged from 881.7 ± 15.45 nm to 1130 ± 15.72 nm, depending on the number of Con A layers. Tenofovir encapsulation efficiency in CaCO3 was 74.4% with drug loading of 16.3% (w/w). MRP was non-cytotoxic to Lactobacillus crispatus, human vaginal keratinocytes (VK2), and murine macrophage RAW 264.7 cells and did not induce any significant proinflammatory nitric oxide release. Overall, compared to control, no statistically significant increase in proinflammatory cytokine IL-1α, IL-1ß, IL-6, MKC, IL-7, and interferon-γ-inducible protein 10 (IP10) levels was observed. Drug release profiles in the presence of methyl α-d-mannopyranoside and recombinant HIV-1 envelope glycoprotein gp120 followed Hixson-Crowell and Hopfenberg kinetic models, indicative of a surface-eroding system. The one Con A layer containing system was found to be the most sensitive (∼2-fold increase in drug release vs control SFS:VFS) at the lowest HIV gp120 concentration tested (25 µg/mL). Percent mucoadhesion, tested ex vivo on porcine vaginal tissue, ranged from 10% to 21%, depending on the number of Con A layers in the formulation. Collectively, these data suggested that the proposed HIV-1 g120 targeting, using MRP, potentially represent a safe and effective template for vaginal microbicide drug delivery, if future preclinical studies are conclusive.