Browsing by Subject "Gardnerella vaginalis"

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    Characterization of Vaginal Microbial Community Dynamics in the Pathogenesis of Incident Bacterial Vaginosis, a Pilot Study
    (Wolters Kluwer, 2023) Elnaggar, Jacob H.; Lammons, John W.; Taylor, Christopher M.; Toh, Evelyn; Ardizzone, Caleb M.; Dong, Amy; Aaron, Kristal J.; Luo, Meng; Tamhane, Ashutosh; Lefkowitz, Elliot J.; Quayle, Alison J.; Nelson, David E.; Muzny, Christina A.; Microbiology and Immunology, School of Medicine
    Background: Despite more than 60 years of research, the etiology of bacterial vaginosis (BV) remains controversial. In this pilot study, we used shotgun metagenomic sequencing to characterize vaginal microbial community changes before the development of incident BV (iBV). Methods: A cohort of African American women with a baseline healthy vaginal microbiome (no Amsel criteria, Nugent score 0-3 with no Gardnerella vaginalis morphotypes) were followed for 90 days with daily self-collected vaginal specimens for iBV (≥2 consecutive days of a Nugent score of 7-10). Shotgun metagenomic sequencing was performed on select vaginal specimens from 4 women, every other day for 12 days before iBV diagnosis. Sequencing data were analyzed through Kraken2 and bioBakery 3 workflows, and specimens were classified into community state types. Quantitative polymerase chain reaction was performed to compare the correlation of read counts with bacterial abundance. Results: Common BV-associated bacteria such as G. vaginalis , Prevotella bivia , and Fannyhessea vaginae were increasingly identified in the participants before iBV. Linear modeling indicated significant increases in G. vaginalis and F . vaginae relative abundance before iBV, whereas the relative abundance of Lactobacillus species declined over time. The Lactobacillus species decline correlated with the presence of Lactobacillus phages. We observed enrichment in bacterial adhesion factor genes on days before iBV. There were also significant correlations between bacterial read counts and abundances measured by quantitative polymerase chain reaction. Conclusions: This pilot study characterizes vaginal community dynamics before iBV and identifies key bacterial taxa and mechanisms potentially involved in the pathogenesis of iBV.
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    Gardnerella vaginalis causing pulmonary infection in a young adult: A novel case
    (Elsevier, 2019-07-25) Bittar, Julie M.; Gazzetta, Joshua; Surgery, School of Medicine
    Gardnerella vaginalis is an anaerobic, gram-variable bacterium primarily found in vaginal microflora of women. Previous reports of G. vaginalis cultured in men are few and have primarily been limited to the gastrointestinal and genitourinary tract.2-4 Few reports of G. vaginalis causing severe infections have been reported in the literature, including septicemia7 and two cases of perinephric abscess.8,9 There has been one previously reported case of G. vaginalis causing pulmonary complications that occurred in a male alcohol abuser. In our case review, we aim to demonstrate an unusual source of a pulmonary infection and highlight the importance of proper microbial isolation to guide treatment. Our patient is a young male who presented following multiple gunshot wounds including one to his head causing an intracranial hemorrhage, hydrocephalus, and a dural sinus thrombosis. His hospital course was complicated by a decline in neurological status treated with a craniotomy and external drain placement and multiple pulmonary infections. During his fever work-ups, he found to have G. vaginalis on mini-bronchoalveolar lavage and was subsequently treated with metronidazole. After treating his G. vaginalis pneumonia and other infectious sources, namely Haemaphilus influenzae and coagulase-negative staphylococcus pneumonias, his fevers and leukocytosis resolved and he was successfully discharged to a rehabilitation facility for neurologic recovery. To our knowledge, this is the second reported case of G. vaginalis isolated from a pulmonary culture and the first in a previously healthy, immunocompetent young male outside of the urinary tract.
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    Resident microbes shape the vaginal epithelial glycan landscape
    (American Association for the Advancement of Science, 2023) Agarwal, Kavita; Choudhury, Biswa; Robinson, Lloyd S.; Morrill, Sydney R.; Bouchibiti, Yasmine; Chilin-Fuentes, Daisy; Rosenthal, Sara B.; Fisch, Kathleen M.; Peipert, Jeffrey F.; Lebrilla, Carlito B.; Allsworth, Jenifer E.; Lewis, Amanda L.; Lewis, Warren G.; Obstetrics and Gynecology, School of Medicine
    Epithelial cells are covered in carbohydrates (glycans). This glycan coat or "glycocalyx" interfaces directly with microbes, providing a protective barrier against potential pathogens. Bacterial vaginosis (BV) is a condition associated with adverse health outcomes in which bacteria reside in direct proximity to the vaginal epithelium. Some of these bacteria, including Gardnerella, produce glycosyl hydrolase enzymes. However, glycans of the human vaginal epithelial surface have not been studied in detail. Here, we elucidate key characteristics of the "normal" vaginal epithelial glycan landscape and analyze the impact of resident microbes on the surface glycocalyx. In human BV, glycocalyx staining was visibly diminished in electron micrographs compared to controls. Biochemical and mass spectrometric analysis showed that, compared to normal vaginal epithelial cells, BV cells were depleted of sialylated N- and O-glycans, with underlying galactose residues exposed on the surface. Treatment of primary epithelial cells from BV-negative women with recombinant Gardnerella sialidases generated BV-like glycan phenotypes. Exposure of cultured VK2 vaginal epithelial cells to recombinant Gardnerella sialidase led to desialylation of glycans and induction of pathways regulating cell death, differentiation, and inflammatory responses. These data provide evidence that vaginal epithelial cells exhibit an altered glycan landscape in BV and suggest that BV-associated glycosidic enzymes may lead to changes in epithelial gene transcription that promote cell turnover and regulate responses toward the resident microbiome.