The association between genital mycoplasmas and bacterial vaginosis in pregnant women with or without genital symptoms

Bacterial vaginosis (BV) and genital mycoplasmas are infections of the reproductive tract that play important roles in maternal and foetal health. Genital mycoplasmas include Mycoplasma genitalium, M. hominis, Ureaplasma parvum and U. urealyticum. Infection may increase a woman’s susceptibility to infection with the human immunodeficiency virus (HIV). Bacterial vaginosis associated bacteria may form biofilms that are responsible for antimicrobial resistance and about 30% of affected women will relapse within three months of treatment. Genital mycoplasmas are prone to develop point mutations, which are responsible for increased antimicrobial resistance. Infections with these bacteria become prominent during pregnancy as infection may lead to infertility and foetal death. The purpose of the study was to determine the association between genital mycoplasmas and BV in pregnant women. Pregnant women attending the antenatal and Maternal and Foetal Unit (MAFU) clinics of a tertiary academic hospital in Pretoria, South Africa were included in the study. Self-collected vaginal swab specimens were obtained from consenting women older than 18 years of age. With the aid of microscopy, the Nugent scoring system was used to diagnose BV. Genital mycoplasmas were cultured on A2 agar and were diagnosed and speciated with a multiplex polymerase chain reaction (mPCR) assay. In addition, genital mycoplasmas were diagnosed and the antimicrobial susceptibility profiles determined with the Mycofast Revolution assay. A quantitative real-time polymerase chain reaction (qPCR) was employed to quantify the BV associated bacteria Atopobium vaginae and Gardnerella vaginalis. The prevalence of BV in this study was found to be 17.7% in 220 recruited pregnant women. Threshold concentrations between 106 to 107 copies/reaction of A. vaginae and G. vaginalis were found to be the best predictors of BV. Genital mycoplasmas were poorly recovered from A2 agar media, which had a contamination rate of 54.9%. An mPCR assay revealed that genital mycoplasmas were prevalent in 2.3% to 71.4% of specimens with U. parvum being the most prevalent species. The resistance of Ureaplasma species to tetracycline and erythromycin was 73% and 80%, respectively. Minor resistance to the fluoroquinolones, levofloxacin and moxifloxacin was recorded. This study found that only the genital mycoplasmas, namely M. hominis and U. parvum, were significantly associated with BV, while M. hominis was also significantly isolated from HIV positive women. This study found that there is an association between BV and genital mycoplasmas. The high prevalence of BV and genital mycoplasmas suggests that current management and/or intervention strategies are insufficient. Bacterial vaginosis associated bacteria can form a polymicrobial biofilm, which confer protection against antimicrobial agents and host immune responses. These biofilms are present on genital sites like the endometrium, which is located close to the amniotic membranes, posing health risks for the pregnancy. Future research must focus on the study of in vitro BV biofilm models and effective treatment strategies to minimise antimicrobial resistance. In the meantime, low-cost point-of-care (POC) tests that can accurately diagnose RTIs are needed to prevent excessive and unnecessary administration of antimicrobial agents and improve maternal and foetal health in the South African health care system.Dissertation (MSc)--University of Pretoria, 2018.Medical MicrobiologyMScUnrestricte

Bacterial vaginosis : current diagnostic avenues and future opportunities

A healthy female genital tract harbors a microbiome dominated by lactic acid and hydrogen peroxide producing bacteria, which provide protection against infections by maintaining a low pH. Changes in the bacterial compositions of the vaginal microbiome can lead to bacterial vaginosis (BV), which is often associated with vaginal inflammation. Bacterial vaginosis increases the risk of acquiring sexually transmitted infections (STIs) like human immunodeficiency virus (HIV) and affects women’s reproductive health negatively. In pregnant women, BV can lead to chorioamnionitis and adverse pregnancy outcomes, including preterm premature rupture of the membranes and preterm birth. In order to manage BV effectively, good diagnostic procedures are required. Traditionally clinical and microscopic methods have been used to diagnose BV; however, these methods require skilled staff and time and suffer from reduced sensitivity and specificity. New diagnostics, including highly sensitive and specific point-of-care (POC) tests, treatment modalities and vaccines can be developed based on the identification of biomarkers from the growing pool of vaginal microbiome and vaginal metabolome data. In this review the current and future diagnostic avenues will be discussed.http://www.frontiersin.org/Cellular_and_Infection_Microbiologyam2020BiochemistryGeneticsMedical MicrobiologyMicrobiology and Plant Patholog

Normal flora and bacterial vaginosis in pregnancy : an overview

The female genital tract is an intricate, yet balanced ecosystem that hosts a variety of different residential microflora. The physiological changes that occur during pregnancy may disrupt this balanced ecosystem and predispose women to a potentially pathogenic microbiota. Bacteria that are associated with bacterial vaginosis (BV) are opportunistic pathogens that frequently form part of this microbiota. The overgrowth of and infections with these bacteria are linked to poor obstetric outcomes and increased transmission of other reproductive tract infections (RTIs). These infections increase women’s susceptibility of acquiring HIV, the rates of HIV shedding and the development of Acquired Immune Deficiency Syndrome (AIDS) in HIV infected patients. It is unknown how the plethora of bacterial species associated with BV contributes to the dynamics of this condition. The use of high-throughput methods have led to the in-depth investigation of different BV-related bacterial species and the functional capabilities of these species. However, the pathogenesis of BV is still poorly defined and the role of individual BV-related bacterial species in specific pregnancy complications is unclear and controversial. The majority of BV infections are asymptomatic and successful diagnosis is complicated by the lack of reliable and standardized diagnostic tests.University of Pretoria, the Medical Research Council (South Africa) and the National Health Laboratory Service (NHLS).http://www.tandfonline.com/loi/imby202017-05-31hb2016Medical Microbiolog

Assessment of Atopobium vaginae and Gardnerella vaginalis concentrations in a cohort of pregnant South African women

OBJECTIVES : The purpose of this cross-sectional study was to assess Atopobium vaginae and Gardnerella vaginalis concentrations in pregnant women of different age groups, gestational age groups, vaginal flora categories and HIV status, and also to determine which DNA concentrations best discriminated between bacterial vaginosis (BV)-positive and non-BV categories. METHODS : Self-collected vaginal swabs were obtained from 220 pregnant women attending an antenatal clinic in Pretoria, Gauteng, South Africa, from July 2012 to December 2012. BV was detected with the Nugent scoring system, and A. vaginae and G. vaginalis DNA was quantified with a multiplex quantitative real-time PCR assay. RESULTS : Median concentrations of A. vaginae and G. vaginalis were not significantly different among various age groups (A. vaginae p=0.98 and G. vaginalis p=0.18) or different trimesters (A. vaginae p=0.31 and G. vaginalis p=0.19), but differed significantly among the vaginal flora categories (A. vaginae p<0.001 and G. vaginalis p<0.001) and HIV status (A. vaginae p<0.001 and G. vaginalis p=0.004). The presence of A. vaginae (OR=5.8; 95% CI 1.34 to 25.21 and p value=0.02) but not that of G. vaginalis (OR=1.90; 95% CI 0.81 to 4.43 and p value=0.14) was associated with HIV infection. An A. vaginae DNA concentration of ≥107 copies/mL together with a positive G. vaginalis result (≥100 copies/mL) best discriminated between BV-positive (39/220) and non-BV categories (181/220) with a sensitivity of 85% (95% CI 0.70 to 0.94) and a specificity of 82% (95% CI 0.76 to 0.88). CONCLUSION : A. vaginae and G. vaginalis were present in high numbers and concentrations in this pregnant cohort. Threshold concentrations should be established for specific populations to ensure sensitive molecular assays for BV detection.The University of Pretoria and the Medical Research Council (South Africa).http://sti.bmj.com2018-09-30hj2017Medical Microbiolog

Comparison of the new Mycofast Revolution assay with a molecular assay for the detection of genital mycoplasmas from clinical specimens

BACKGROUND: Genital mycoplasmas are opportunistic bacteria that are associated with undesirable gynaecologic and reproductive events. Mycoplasmas are fastidious bacteria with increasing resistance to routine antimicrobials and often fail to grow on conventional culture methods. The commercial Mycofast Revolution assay permits the phenotypic detection and identification of genital mycoplasmas. Antimicrobial susceptibility testing against five antimicrobial agents with MICs corresponding to the CLSI guidelines can also be performed. This study aimed to compare the new commercially available Mycofast Revolution assay with a multiplex PCR assay. METHODS: Self-collected swabs were obtained from pregnant women attending the antenatal clinic of a tertiary academic hospital in Pretoria, South Africa from October 2012 to November 2012. These swabs were used to seed UMMt and modified Amies transport media. The seeded UMMt transported medium was used to inoculate the Mycofast Revolution assay for the identification, enumeration and antimicrobial susceptibility testing of genital mycoplasmas. Following DNA extraction from the modified Amies transport medium, specimens were subjected to a multiplex PCR assay for the detection of genital mycoplasmas. RESULTS: The Mycofast Revolution kit had a sensitivity and specificity of 77.3% (95% CI: 62.15% to 88.51%) and 80% (95% CI: 28.81% to 96.70%), respectively, against the PCR assay. The positive and negative predictive values were 97.1% (95% CI: 85.03% to 99.52%) and 28.6% (95% CI: 8.57% to 58.08%). Genital mycoplasmas were detected in 71.4% (35/49) of samples with the Mycofast Revolution assay with 49% (24/49) being Ureaplasma spp. and 22.4% (11/49) mixed strains. The multiplex PCR assay had a positivity rate of 89.8% (44/49) for genital mycoplasmas; mixed strains were present in 51% (25/49) of samples, Ureaplasma spp. in 16.3% (8/49) and M. hominis in 22.4% (11/49) of samples. CONCLUSIONS: There was a fair agreement (κ = 0.319) between the Mycofast Revolution assay and the mPCR assay. With the high prevalence rates of genital mycoplasmas, fast and efficient diagnostic methods are imperative to treat infections and minimise complications. The Mycofast Revolution assay is simple to use, has a short turnaround time and interpretation of results are straightforward. This assay circumvents common problems experienced with conventional culture and molecular methods in diagnostic laboratories where skilled personnel are limited and can be used as an alternative diagnostic assay.http://www.biomedcentral.com/1471-2334/13/453am201

Antimicrobial susceptibility patterns of Ureaplasma species and Mycoplasma hominis in pregnant women

BACKGROUND : Genital mycoplasmas colonise up to 80% of sexually mature women and may invade the amniotic cavity during pregnancy and cause complications. Tetracyclines and fluoroquinolones are contraindicated in pregnancy and erythromycin is often used to treat patients. However, increasing resistance to common antimicrobial agents is widely reported. The purpose of this study was to investigate antimicrobial susceptibility patterns of genital mycoplasmas in pregnant women. METHODS : Self-collected vaginal swabs were obtained from 96 pregnant women attending an antenatal clinic in Gauteng, South Africa. Specimens were screened with the Mycofast Revolution assay for the presence of Ureaplasma species and Mycoplasma hominis. The antimicrobial susceptibility to levofloxacin, moxifloxacin, erythromycin, clindamycin and tetracycline were determined at various breakpoints. A multiplex polymerase chain reaction assay was used to speciate Ureaplasma positive specimens as either U. parvum or U. urealyticum. RESULTS : Seventy-six percent (73/96) of specimens contained Ureaplasma spp., while 39.7% (29/73) of Ureaplasma positive specimens were also positive for M. hominis. Susceptibilities of Ureaplasma spp. to levofloxacin and moxifloxacin were 59% (26/44) and 98% (43/44) respectively. Mixed isolates (Ureaplasma species and M. hominis) were highly resistant to erythromycin and tetracycline (both 97% resistance). Resistance of Ureaplasma spp. to erythromycin was 80% (35/44) and tetracycline resistance was detected in 73% (32/44) of Ureaplasma spp. Speciation indicated that U. parvum was the predominant Ureaplasma spp. conferring antimicrobial resistance. CONCLUSIONS : Treatment options for genital mycoplasma infections are becoming limited. More elaborative studies are needed to elucidate the diverse antimicrobial susceptibility patterns found in this study when compared to similar studies. To prevent complications in pregnant women, the foetus and the neonate, routine screening for the presence of genital mycoplasmas is recommended. In addition, it is recommended that antimicrobial susceptibility patterns are determined.University of Pretoria, the Medical Research Council (South Africa) and the National Health Laboratory Service (NHLS)http://www.biomedcentral.com/bmcinfectdis/hb201

A cross-sectional study on the relationship of age, gestational age and HIV infection to bacterial vaginosis and genital mycoplasma infection

OBJECTIVES : Pregnant women are especially at risk of developing complications when infected with reproductive tract infections (RTIs). The objective of this study was to determine the prevalence of bacterial vaginosis (BV) and genital mycoplasmas in pregnant women and investigate the associations between BV, genital mycoplasmas, HIV infection, age and gestational age. DESIGN : Cross-sectional study with descriptive and analytical components. SETTING : Antenatal clinic of a tertiary academic hospital in South Africa. PARTICIPANTS : 220 pregnant women older than 18 were included in the study and provided self-collected vaginal swabs. PRIMARY AND SECONDARY OUTCOMES : BV and genital mycoplasma colonisation and/or infection in women of differing age, gestational period and HIV status. RESULTS : The prevalence of BV was 17.7% (39/220) (95% CI 12.9 to 23.4), intermediate vaginal flora (IVF) 15% (33/220) (95% CI 10.56 to 20.42), and the overall prevalence of genital mycoplasmas was 84% (185/220) (95% CI 78.47 to 88.58). BV was significantly associated with HIV infection with an OR of 2.84 (95% CI 1.08 to 7.46 and p value=0.034). However, BV was inversely associated with gestational age with an OR of 0.08 (95% CI 0.01 to 0.42 and p value=0.003) for second trimester pregnancies and an OR of 0.03 (95% CI 0.01 to 0.17 and p value<0.001) for third trimester pregnancies using the first trimester as reference. IVF was significantly associated with HIV infection with an OR of 2.7 (95% CI 1.07 to 6.79 and p value=0.035) but not with age or gestational age. Genital mycoplasmas were not significantly associated with age, gestational age, HIV status, BV flora or IVF. CONCLUSIONS : The high infection rate of genital mycoplasmas and the association of BV with HIV found in this study reiterate the importance of screening for these RTIs in high-risk groups such as pregnant women.The University of Pretoria and the Medical Research Council (South Africa).http://bmjopen.bmj.comam201

Diversity of the gut, vaginal and oral microbiome among pregnant women in South Africa with and without pre-eclampsia

The datasets presented in this study can be found in online repositories. The names of the repository/repositories and accession number(s) can be found below: NCBI SRA database, accession number PRJNA798597 (BioProjectID).BACKGROUND : Changes in microbial communities are a known characteristic of various inflammatory diseases and have been linked to adverse pregnancy outcomes, such as preterm birth. However, there is a paucity of information regarding the taxonomic composition and/or diversity of microbial communities in pre-eclampsia. The aim of this study was to determine the diversity of the gut, vaginal and oral microbiome in a cohort of South African pregnant women with and without pre-eclampsia. The diversity of the gut, vaginal and oral microbiome was determined by targeted next generation sequencing (NGS) of the V3 and V4 region of the 16S rRNA gene on the Illumina MiSeq platform. RESULTS : In this study population, pre-eclampsia was associated with a significantly higher alpha diversity (P = 0.0472; indicated by the Shannon index) in the vaginal microbiome accompanied with a significant reduction in Lactobacillus spp. (P = 0.0275), compared to normotensive pregnant women. Lactobacillus iners was identified as the predominant species of the vaginal microbiome in both cohorts. High inter-individual variation in alpha diversity was observed in the gut and oral microbiome in both cohorts. Although differences in the relative abundance of bacteria at all phylogenetic levels were observed, overall microbial composition of the gut, oral and vaginalmicrobiome was not significantly different in the pre-eclampsia cohort compared to the normotensive cohort. CONCLUSION : Collectively, a reduction of Lactobacillus spp., and predominance of L. iners in pregnant women with pre-eclampsia could suggest an unstable vaginal microbiome that might predispose pregnant women to develop pre- eclampsia. The lack of significant structural changes in the gut, oral and vaginal microbiome does not suggest that the characterized communities play a role in pre-eclampsia, but could indicate a characteristic unique to the study population. The current study provided novel information on the diversity of the gut, oral and vaginal microbiome among pregnant women in South Africa with and without pre-eclampsia. The current study provides a baseline for further investigations on the potential role of microbial communities in pre-eclampsia.The University of Pretoria and the National Health Laboratory Service (NHLS).https://www.frontiersin.org/journals/global-womens-healtham2023BiochemistryGeneticsMedical MicrobiologyMicrobiology and Plant Patholog

Growth forms of Gardnerella spp. and Lactobacillus spp. on vaginal cells

Bacterial vaginosis (BV) is a common vaginal condition in women of reproductive age. During BV development, BV-associated bacteria may form a polymicrobial biofilm, which predispose women to recurrent BV. The aim of the study was to investigate the growth forms of Gardnerella spp. and Lactobacillus spp. and to determine the association between the bacterial growth forms and clinical characteristics [urinary tract infection (UTI) symptoms, human immunodeficiency virus (HIV) infection and abnormal vaginal discharge] in women attending a tertiary hospital in Pretoria, South Africa. A first-void urine specimen was collected from 196 women and BV was diagnosed using the Nugent scoring and the Ison-Hay criteria (vaginal smear microscopy). Fluorescence in situ hybridisation (FISH) was performed to classify the growth forms [“dispersed” or “biofilm”]. Bacterial cells were categorized as “dispersed” if cells were scattered separately and as “biofilm” if bacterial aggregates on the vaginal epithelial cells were observed. BV was detected in 52 women (52/196; 27%) and in these women, Gardnerella spp. were predominantly present in biofilms (46/52; 88% for Nugent scoring; and 45/50; 90% for Ison-Hay criteria), whereas Lactobacillus spp. were predominantly present in a dispersed form (38/52; 73% for Nugent scoring; and 37/50; 74% for Ison-Hay criteria). The odds of having BV increased when Gardnerella biofilms were present (p < 0.001), whereas the opposite was observed for Lactobacillus biofilms (p = 0.001). Neither Gardnerella spp. or Lactobacillus spp. (both dispersed or biofilms) had an association with the presence of UTI symptoms, HIV coinfection or abnormal vaginal discharge. In conclusion, this study demonstrated and confirmed that Gardnerella biofilms are associated with BV and that Lactobacillus spp. may form biofilms to protect against BV.The Medical Research Council (MRC) of South Africa and National Health Laboratory Service (NHLS) of South Africa.http://frontiersin.org/Cellular_and_Infection_Microbiologypm2021Medical MicrobiologySchool of Health Systems and Public Health (SHSPH

Chlamydia trachomatis biovar L2 infection in women in South Africa

We detected Chlamydia trachomatis biovar L2 in vaginal swab specimens of 7 women with vaginal discharge in South Africa. Whole-genome sequencing directly from clinical specimens identified a closely related cluster of strains. The clinical role of this infection in the context of syndromic management should be clarified