<p>The Pathogenesis Of<em> Streptococcus anginosus</em> In Aerobic Vaginitis</p>

Abstract

BackgroundAerobic vaginitis (AV) is a newly defined type of bacterial vaginitis, but its pathogenesis is not yet clear. Streptococcus anginosus appears as an emerging pathogen in recent case reports, and colonizes in vagina of patients with AV. In this study, we investigate the pathogenesis of S. anginosus in AV.Materials and methods(1) We collected 41 vaginal specimens from 21 healthy, fertile women with normal vaginal flora (NM), 10 with bacterial vaginosis (BV) and 10 with AV; their microbiome structure was analysed by 16S rRNA gene sequencing. (2) S. anginosus and vaginal epithelial cells were cocultured in vitro, and cytotoxicity was tested by an LDH kit. (3) The S. anginosus virulence gene sag was knocked out, and the cytotoxicity of the mutant in vaginal epithelial cells was tested.Results(1) The microbiome structure of AV was dramatically different from that of BV and NM. The predominant genera of the three groups were Streptococcus spp., Gardnerella spp. and Lactobacillus spp. Streptococcus spp. were significantly more abundant in AV than in BV (95% CI [0.1391, 0.8676], P<0.01) and NM (95% CI [0.1391, 0.8676], P<0.01). (2) S. anginosus was the dominant species in AV (95% CI [0.04672, 0.1097], P<0.01). (3) The mean cytotoxicity of S. anginosus in vaginal epithelial cells was 58.34% for the wild type (WT) and 16.43% for the mutant; this difference was significant (95% CI [−60.55, −23.28], P<0.01).ConclusionS. anginosus was the predominant microorganism in patients with AV in our study. S. anginosus caused vaginal epithelial cell lysis, indicating that S. anginosus is an AV pathogen. The S. anginosus virulence gene sag is vital for vaginal epithelial cell lysis.

Recovery of Vaginal Microbiota after Standard Treatment for Bacterial Vaginosis Infection: An Observational Study

“…Although BV diagnosis based on Nugent score for these women is contradictory, sequencing analysis showed that these women also had significantly higher abundance of S. anginosus and Gram-positive anaerobic cocci (Peptoniphilus sp., Anaerococcus sp., and Finegoldia sp. ), which have been associated with BV/vaginal infections [28][29][30]. Given the non-specificity and subjectivity of Nugent scoring method, our study results are aligned with previous recommendations that prospective BV treatment studies should be analyzed based on the microbiota and not exclusively on the Nugent score [27,31].…”

Human beta defensin levels and vaginal microbiome composition in post-menopausal women diagnosed with lichen sclerosus

“…Successful binding of these bacteria to extracellular matrix proteins, like fibronectin, fibrinogen and laminin plays an important role in their pathogenesis 22 . The sag haemolysin of S. anginosus has been described to initiate vaginal epithelial cell lysis 23 .…”

The Interaction Between Microorganisms, Metabolites, and Immune System in the Female Genital Tract Microenvironment

“…In 2020, Budilovskaya et al (2020) found that the expression of IL1b, IL-6, IL-8, IL10, tumor necrosis factor-a (TNFa) and CD68 messenger ribose nucleic acids (mRNAs) in AV patients was significantly increased, and this change was related to itching or burning as well as increases in leukocytes and parabasal epithelial cells under the microscope (Smith and Ravel, 2017). Purulent vaginal discharge and vaginal redness may be related to the toxic effect of the virulence gene sag of Streptococcus anginosus on epithelial cells, leading to epithelial cell lysis (Tao et al, 2019).…”

“…The incidence of AV in women of childbearing age is approximately 10% ( Donders et al., 2017 ). Significantly different from BV patients and those with a normal flora, AV patients have increased aerobic bacteria or enterococci, such as Escherichia coli , Streptococcus agalactiae , Staphylococcus aureus , Staphylococcus epidermidis , Streptococcus anginosus , and Enterococcus faecalis , in the vagina ( Donders et al., 2017 ; Tao et al., 2019 ; Wang et al., 2020 ). Studies have also shown that BV-related bacteria often appear in the vaginal flora of AV patients, which may be related to the symbiotic relationship between BV- and AV-related bacteria in the state of flora disorder ( Wang et al., 2020 ).…”

“…The host’s innate and adaptive immune systems perform complex interactions with microorganisms and metabolites ( Agostinis et al., 2019 ; Delgado-Diaz et al., 2019 ). Microbial ligands bind to host receptors to produce inflammatory factors, chemokines and antimicrobial products to regulate the immune response of the reproductive tract ( Hooper et al., 2012 ).Vaginal dysbiosis cannot only directly cause vaginal epithelial injury through pathogens ( Tao et al., 2019 ), but also indirectly cause vaginal epithelial injury through immune components, which in turn release metabolites into the microenvironment ( Olive and Sassetti, 2016 ; Serrano et al., 2019 ). This metabolite may be ingested by the vaginal microbiota, leading to increased microbial metabolism, which is beneficial to the growth and reproduction of the microbiota ( Serrano et al., 2019 ).…”