Prevalence of vaginolysin, sialidase and phospholipase genes in Gardnerella vaginalis isolates between bacterial vaginosis and healthy individuals

Prevalence of Gardnerella vaginalis infection and antibiotic resistance pattern of isolates of gynecology clinic patients at Shahriar Noor Hospital from January to June 2020 by PCR and culture methods

Background and Objectives

Gardnerella vaginalis is one of the most important causes of prevalent genital infections that pose serious risks. This study aimed to determine the prevalence of Gardnerella vaginalis and antibiotic resistance pattern of isolates of patients referred to the gynecology clinic of Shahriar Noor Hospital by PCR and culture methods.

Materials and Methods

The study was conducted on 500 patients who had suffered from a vaginal infection. The demographic data of patients were studied. For diagnosis of Gardnerella vaginalis isolates, cultivation in anaerobic conditions, biochemical tests, PCR and Gardnerella vaginalis antibiotic susceptibility test to metronidazole and clindamycin were performed. Data analysis was performed utilizing SPSS statistical software version 19 and the Chi-square test.

Results

Among the 500 patients, 173 were diagnosed with Gardnerella vaginitis. There was a significant relationship between age group, level of education, and contraceptive method with Gardnerella vaginosis incidence. Performing antibiotic susceptibility tests showed that the resistance of Gardnerella vaginalis isolated strains to metronidazole and clindamycin was 86.12% and 17.34%, respectively.

Conclusion

The high prevalence of Gardnerella vaginalis infections confirms the critical role of the bacterium in the occurrence of bacterial vaginosis. Therefore, it is necessary to check the prevalence of bacterial infections to recommend the correct medical treatment in different societies.

Biofilm and pathogenic factor analysis of Gardnerella vaginalis associated with bacterial vaginosis in Northeast China

Introduction

Gardnerella vaginalis is a major pathogen responsible for bacterial vaginosis (BV). However, the recurrence of infection and the antibiotic resistance of biofilms remain significant challenges for the treatment of BV. In this study, we aimed to analyze the pathogenic factors and drug sensitivity associated with the clinical treatment of BV in Northeast China.

Methods

Subgroups were identified by clade-specific polymerase chain reaction (PCR). Biofilm formation was measured by crystal violet staining, confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM). The inhibition and eradication of biofilm formation were measured by XTT and broth recovery-based methods.

Results

Of the 24 samples of G. vaginalis, 11 samples and American Type Culture Collection (ATCC) 14018 formed biofilms; the remainder did not. The positive rates of detection for the sialidase A and vly genes in the 24 G. vaginalis samples were 100% and 79.2%, respectively. Moreover, 21 samples (87.5%) showed resistance to metronidazole and 16 (66.7%) presented with sensitivity towards clindamycin. The biofilm MIC₈₀ (BMIC₈₀) of metronidazole for ATCC14018 was 16 μg/ml while that of clindamycin was 0.125 μg/ml. The minimum biofilm eradication concentration (MBEC) of metronidazole was > 256 μg/ml while that of clindamycin was > 2 μg/ml.

Discussion

Our results revealed that G. vaginalis is more resistant to metronidazole than clindamycin and neither metronidazole nor clindamycin are able to effectively eradicate vaginal biofilms. Thus, the role of antibiotics and biofilms in BV requires further investigation.

Roles of the Microbiota of the Female Reproductive Tract in Gynecological and Reproductive Health

The microbiome of the female reproductive tract defies the convention that high biodiversity is a hallmark of an optimal ecosystem. Although not universally true, a homogeneous vaginal microbiome composed of species of Lactobacillus is generally associated with health, whereas vaginal microbiomes consisting of other taxa are generally associated with dysbiosis and a higher risk of disease. The past decade has seen a rapid advancement in our understanding of these unique biosystems. Of particular interest, substantial effort has been devoted to deciphering how members of the microbiome of the female reproductive tract impact pregnancy, with a focus on adverse outcomes, including but not limited to preterm birth. Herein, we review recent research efforts that are revealing the mechanisms by which these microorganisms of the female reproductive tract influence gynecologic and reproductive health of the female reproductive tract.

Vaginal sialoglycan foraging by Gardnerella vaginalis: mucus barriers as a meal for unwelcome guests?

Bacterial vaginosis (BV) is a condition of the vaginal microbiome in which there are few lactobacilli and abundant anaerobic bacteria. Members of the genus Gardnerella are often one of the most abundant bacteria in BV. BV is associated with a wide variety of poor health outcomes for women. It has been recognized since the 1980s that women with BV have detectable and sometimes markedly elevated levels of sialidase activity in vaginal fluids and that bacteria associated with this condition produce this activity in culture. Mounting evidence collected using diverse methodologies points to the conclusion that BV is associated with a reduction in intact sialoglycans in cervicovaginal secretions. Here we review evidence for the contributions of vaginal bacteria, especially Gardnerella, in the processes of mucosal sialoglycan degradation, uptake, metabolism and depletion. Our understanding of the impacts of vaginal sialoglycan degradation is still limited. However, the potential implications of sialic acid depletion are discussed in light of our current understanding of the roles played by sialoglycans in vaginal physiology.