Mycoplasma hominis and Gardnerella vaginalis display a significant synergistic relationship in bacterial vaginosis

Characteristics of Vaginal Microbiota of Women of Reproductive Age with Infections

The vaginal microbiota can be classified into five major community state types (CSTs) based on the bacterial content. However, the link between different CST subtypes and vaginal infection remains unclear. Here, we analyzed 2017 vaginal microbiota samples from women of a reproductive age with vaginal infections that were published in the last decade. We found that L. iners was the most dominant in 34.8% of the vaginal samples, followed by L. crispatus (21.2%). CST I was common in healthy individuals, whereas CST III and IV were associated with dysbiosis and infection. CST III-B, IV-A, IV-B, and IV-C0 were prevalent in patients with bacterial vaginosis (BV). Based on the relative abundance of bacteria at the (sub)genus level, a random forest classifier was developed to predict vaginal infections with an area under the curve of 0.83. We further identified four modules of co-occurring bacterial taxa: L. crispatus, Gardnerella, Prevotella, and Bacteroides. The functional prediction revealed that nucleotide biosynthesis pathways were upregulated in patients with human papilloma virus, and carbohydrate degradation pathways were downregulated in patients with BV. Overall, our study identified the bacterial signatures of healthy and infected vaginal microbiota, providing unique insights into the clinical diagnosis and health status prediction of women of a reproductive age.

Bacterial vaginosis after menopause: factors associated and women's experiences: a cross-sectional study of Australian postmenopausal women

Background Bacterial vaginosis (BV) is the most common cause of vaginal discharge in reproductive age women; however, little is known about it after menopause. We aimed to learn more about BV in Australian postmenopausal women. Methods We conducted an online survey (July-September 2021). Participants were recruited via social media and professional networks and asked about demographic characteristics, sexual history and BV experiences. Outcomes of interest were the proportion who had heard of BV, had BV ever, or had BV after menopause. Factors associated with these outcomes were assessed using logistic regression. Results Of 906 participants, 83% were included in the analysis. Overall, 37.9% had heard of BV, 11.0% reported having a BV diagnosis ever, 6.3% reported having a BV diagnosis after menopause and 4.4% reported having a BV diagnosis only after menopause. Multivariable analysis found that among all women the odds of having a BV diagnosis after menopause were increased for those who had BV before menopause, had douched in the past 12months, or had a previous STI diagnosis. Among those in a sexual relationship, a BV diagnosis after menopause was associated with a BV diagnosis before menopause, or being in a sexual relationship of 5years or less in duration. About half who reported BV after menopause described recurrences, distress, and a detrimental effect on sexual relationships. Conclusions BV in postmenopausal women is associated with sexual activity, and impacts negatively on their lives. Research into BV should not be limited to reproductive age women.

Antimicrobial Resistance of Genital Mycoplasma and Ureaplasma: A Multicentre Study Over a 5-Year Period in Italy (2017-2021)

Updated data on genital Mollicutes prevalence and antimicrobial susceptibility can help provide guidance for antibiotic stewardship and set up effective strategies for infection control policies. In this multicentre study, we assessed the prevalence and the resistance profile of Mycoplasma hominis (MH) and Ureaplasma species (U. parvum/U. urealyticum), analyzing data from 21,210 subjects who provided urogenital samples for Mollicutes detection by culture over a 5-year period (2017-2021) in two high-density urban areas in the North of Italy (i.e., Bologna and Lecco). Overall prevalence of Mollicutes infection was 22.3%, with women showing a significantly higher detection rate than men (p < 0.00001). The prevalence decreased with age (highest prevalence <30 years) and over the years considered. Ureaplasma strains were much more frequently detected (62.3%) compared to MH (8.3%) and to mixed infections (29.4%). Ureaplasma species showed high levels of ciprofloxacin resistance (39.5%), whereas MH strains were nonsusceptible to azithromycin and roxithromycin in about 60% of cases. Over time, a significant decrease of resistance to azithromycin and doxycycline was detected (p < 0.0001 and 0.0004, respectively), in parallel with an important increase of ciprofloxacin-resistance levels (p < 0.0001). Overall, our results revealed that minocycline and josamycin can be first-line drugs for Mollicutes empirical treatment.

A Systematic Review of Curtisia dentata Endemic to South Africa: Phytochemistry, Pharmacology, and Toxicology

The use of traditional medicine in treating a variety of both human and animal infections is ancient and still relevant. This is due to the resistance exhibited by most pathogenic microbial stains to currently-used antibiotics. The current work reports the phytochemistry, ethno-medicinal uses, toxicology, and most important pharmacological activities that validate the use of the plant species in African traditional medicine. Curtisia dendata is used in the treatment of many human and animal infections, including diarrhea, skin and related conditions, sexually transmitted infections, cancer, and a variety of ethno-veterinary infections. Pharmacologically, the plant species exhibited potent antimicrobial activity against a variety of pathogens. Further, both extracts and compounds isolated from the plant species exhibited potent antioxidant, anticancer, anti-parasitic, anti-inflammatory, and other important biological activities. Phytochemically, the plant species possess a variety of compounds, particularly triterpenes, that may well explain the various pharmacological activities of the plant species. The toxicological parameters, antimicrobial activities against microorganisms related to sexually transmitted infections, anti-diabetic effects, and inflammatory properties of the plant species are not well studied and still need to be explored. The biological activities observed validate the use of the plant species in African traditional medicine, particularly in the treatment of pulmonary infections associated with Mycobacterium species, and may well be due to the presence of triterpenes prevalent in the leaves.

Association of intermediate Nugent Score and bacterial vaginosis with sexually transmitted infections and vulvovaginal candidiasis

Background Bacterial vaginosis is a common vaginal syndrome among females, which leads to significant morbidity and complications, if left untreated. The association of bacterial vaginosis with various sexually transmitted infections has been mentioned in previous literature. However, studies on the intermediate Nugent Score are lacking. This study was planned to examine the association of sexually transmitted infections with the intermediate Nugent Score. Materials and Methods The study included was conducted to include females presenting with vaginal discharge, burning micturition, itching, lower abdominal pain and infertility. The Nugent scoring was used to categorize patients into those having normal flora, intermediate or bacterial vaginosis. Conventional and molecular techniques targeting Trichomonas vaginalis, Chlamydia trachomatis, Ureaplasma urealyticum, Mycoplasma hominis, Syphilis, Neisseria gonorrhoeae and vulvovaginal candidiasis were performed. Results A total of 3,531 clinical samples were collected from females with a median age of 28.0 years. The number of patients with bacterial vaginosis and intermediate Nugent Score and positive cases were significantly higher in the 21-35 years age group (P < 0.0001). We observed that the likelihood of test results being positive for Trichomonas vaginalis was higher (P < 0.05), as the abnormality of the vaginal flora increased. Mycoplasma hominis was observed to be significantly higher in the intermediate Nugent Score group than the BV-positive patients (0.6 vs 0.2, P = 0.002). The number of vulvovaginal candidiasis cases in both the bacterial vaginosis-negative and bacterial vaginosis-positive groups were nearly the same (9.3 vs 9.8%). Limitation Individual follow-up couldn't be performed on the patients. Conclusion We observed that the dysbiosis in vaginal microbiota, with an increase in Nugent scoring, was significantly associated with an increased risk for the acquisition of sexually transmitted infections and vulvovaginal candidiasis.

The Prevalence of Genital Mycoplasmas and Coinfection with Trichomonas vaginalis in Female Patients in Vienna, Austria

Trichomonas vaginalis causes trichomoniasis, the most recurrent sexually transmitted infection (STI) worldwide. Genital mycoplasmas, not considered STI agents, are frequently isolated from the female genital tract. A symbiosis between Mycoplasma species and T. vaginalis has been described. The aim of this study was to conduct molecular-based analyses of vaginal specimens, thus assessing the prevalence of non-STI Mycoplasma infections. In total, 582 samples from female patients and an additional 20 T. vaginalis isolates were analyzed by PCR using Mycoplasma specific 16S rRNA primers, and the obtained PCR products were sequenced. Mycoplasma species were detected in 28.2% of the collected vaginal samples. Mycoplasma hominis was found in 21.5% of the specimens, Ureaplasma species were found in 7.5% of the samples. The molecular data of the newly described species, CandidatusMycoplasma girerdii, were obtained for the first time in Austria, in a sample also positive for T. vaginalis. Analyses of the cultivated T. vaginalis strains confirmed the presence of M. hominis in two out of 20 samples. A comparably high prevalence of genital mycoplasmas was revealed through advanced diagnostic assays, with M. hominis and U. parvum being the most prevalent species. The previously described symbiotic relationship between M. hominis and T. vaginalis was confirmed.

Optimal sampling and analysis methods for clinical diagnostics of vaginal microbiome

Next-generation sequencing-based microbiological analysis is a complex way to profile vaginal microbiome samples since each step affects the results gained. Methodologies for sample collection lack golden standards. We compared Puritan DNA/RNA swab (PS) and Copan FLOQ swab (CS) and provided consistent and reliable microbiome profiles analyzed by 16S rRNA gene sequencing. We collected two consecutive vaginal samples utilizing PS with room temperature storing and CS with instant freezing from 26 women. Variable region 4 of bacterial 16S rRNA gene was amplified with single PCR by custom-designed dual-indexed primers and sequenced with Illumina MiSeq system. Read quality control, operational taxonomic unit tables, and alpha and beta diversities analysis were performed, and community richness, diversity, and evenness were evaluated and compared between the two samplings and tests. Nineteen sample pairs produced detectable, intact DNA during the extraction protocol and/or further microbial profiles. Alpha bacterial diversity indices were independent on the collection protocol. No significant statistical differences were found in the measured beta diversity metrics between the collection methods. Of the women, 43% had Lactobacillus-dominated vaginal microbiome profile despite of collection method. Previously reported important vaginal microbiome phyla Actinobacteria, Bacteroidetes, Firmicutes, Fusobacteria, and Proteobacteria were present in the sample set although their relative abundances varied among individuals. PS and CS enable constant vaginal microbiota sampling. The PS method with no need for instant freezing is suitable for on-site collections at clinics. Furthermore, it seems to be possible to take two samples instead of one with constant microbiological results.

Mycoplasma hominis Causes DNA Damage and Cell Death in Primary Human Keratinocytes

Mycoplasma hominis can be isolated from the human urogenital tract. However, its interaction with the host remains poorly understood. In this study, we aimed to assess the effects of M. hominis infection on primary human keratinocytes (PHKs). Cells were quantified at different phases of the cell cycle. Proteins involved in cell cycle regulation and apoptosis progression were evaluated. The expression of genes encoding proteins that are associated with the DNA damage response and Toll-like receptor pathways was evaluated, and the cytokines involved in inflammatory responses were quantified. A greater number of keratinocytes were observed in the Sub-G0/G1 phase after infection with M. hominis. In the viable keratinocytes, infection resulted in G2/M-phase arrest; GADD45A expression was increased, as was the expression of proteins such as p53, p27, and p21 and others involved in apoptosis regulation and oxidative stress. In infected PHKs, the expression of genes associated with the Toll-like receptor pathways showed a change, and the production of IFN-γ, interleukin (IL) 1β, IL-18, IL-6, and tumour necrosis factor alpha increased. The infection of PHKs by M. hominis causes cellular damage that can affect the cell cycle by activating the response pathways to cellular damage, oxidative stress, and Toll-like receptors. Overall, this response culminated in the reduction of cell proliferation/viability in vitro.

Molecular Epidemiology of Genital Infections in Campania Region: A Retrospective Study

This study provides updated information on the prevalence and co-infections caused by genital microorganisms and pathogens: Mycoplasma genitalium, Mycoplasma hominis, Ureaplasma parvum, Ureaplasma urealyticum, Trichomonas vaginalis, and Gardnerella vaginalis, by retrospectively analyzing a cohort of patients living in the Naples metropolitan area, Campania region, Southern Italy. To investigate the genital infections prevalence in clinical specimens (vaginal/endocervical swabs and urines) collected from infertile asymptomatic women and men from November 2018 to December 2020, we used a multiplex real-time PCR assay. Of the 717 specimens collected, 302 (42.1%) resulted positive for at least one of the targets named above. Statistically significant differences in genital prevalence of selected microorganisms were detected in both women (62.91%) and men (37.08%). G. vaginalis and U. parvum represented the most common findings with an 80.2% and 16.9% prevalence in vaginal/endocervical swabs and first-voided urines, respectively. Prevalence of multiple infections was 18.18% and 8.19% in women and men, respectively. The most frequent association detected was the co-infection of G. vaginalis and U. parvum with 60% prevalence. Our epidemiological analysis suggests different infection patterns between genders, highlighting the need to implement a preventative screening strategy of genital infections to reduce the complications on reproductive organs.

The associations between low abundance of Mycoplasma hominis and female fecundability: a pregnancy-planning cohort study

Objective

To explore the impact of pre-pregnancy vaginal Mycoplasma hominis (M. hominis) colonization of low abundance on female fecundability.

Methods

In total, 89 females participating in a pre-pregnancy health examination program were included, and their pregnancy outcomes were followed up for 1 year. Vaginal swabs were collected, 16S rRNA genes were sequenced, and M. hominis colonization was confirmed by qPCR. Cox models were used to estimate the fecundability odds ratio (FOR) for women with M. hominis.

Results

The prevalence of M. hominis was 22.47% (20/89), and the abundance was relatively low (the cycle thresholds of the qPCR were all more than 25). In terms of the vaginal microbiome, the Simpson index of the positive group was significantly lower than that of the negative group (P = 0.003), which means that the microbiome diversity appeared to increase with M. hominis positivity. The relative abundance of M. hominis was negatively correlated with Lactobacillus crispatus (rho = − 0.24, P = 0.024), but positively correlated with Gardnerella vaginalis, Atopobium vaginae and Prevotella bivia (P all < 0.05). The cumulative one-year pregnancy rate for the M. hominis positive group was lower than that in the negative group (58.96% vs 66.76%, log-rank test: P = 0.029). After controlling for potential confounders, the risk of pregnancy in the M. hominis positive group was reduced by 38% when compared with the positive group (FOR = 0.62, 95% CI: 0.42–0.93).

Conclusion

The vaginal colonization of M. hominis at a low level in pre-pregnant women is negatively correlated with female fecundability.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12866-022-02545-7.

Prevalence of bacterial vaginosis in postmenopausal women: a systematic review and meta-analysis

Bacterial vaginosis (BV), the most common cause of vaginal discharge in women of reproductive age, is associated with considerable reproductive and gynaecological sequelae and increases the risk of acquiring sexually transmissible infections including HIV. Although we understand the burden of BV in women of reproductive age, much less is known about the burden of BV in postmenopausal women. We undertook this systematic review and meta-analysis to estimate the prevalence of BV in postmenopausal women. The electronic databases PubMed, EMBASE, Web of Science, and The Cochrane Library were searched for English-language papers reporting on the prevalence of BV in postmenopausal women and published up until the end of July 2020. Search terms included: (prevalence OR survey OR proportion) AND 'bacterial vaginosis'. Meta-analysis was used to calculate pooled estimates of prevalence. We identified 2461 unique references and assessed 328 full-text articles for eligibility, with 13 studies included in the meta-analysis. The prevalence of BV ranged from 2.0 to 57.1%, with a summary estimate of 16.93% (95% CI: 8.5-27.4; I 2 =97.9). There was considerable heterogeneity between studies and quality varied considerably. Further research is needed to provide a better understanding of the condition in postmenopausal women and understand its effect on their lives.

Cross sectional study to evaluate microbiological spectrum of RTI/STI and co-infections among women with cervicitis or cervico-vaginitis from a community clinic in Mumbai

Cervicitis is an inflammatory condition of cervix, when presented along with vaginal discharge; it is termed as cervico-vaginitis. These can be infective, hence important to diagnose due to risk of spreading to upper genital tract. This cross-sectional study was undertaken to evaluate the microbiological spectrum in cervicitis or cervico-vaginitis among 100 sexually active women by Gram stain and Multiplex Real time polymerase chain reaction. Bacterial vaginosis 21(21%) was the most common RTI. Among STIs, genital mycoplasmas were the predominant infections hence further research is required to understand their pathogenesis.

Genital mycoplasma infection and spontaneous preterm birth outcome: a prospective cohort study

OBJECTIVE

To assess the risk of spontaneous preterm birth (sPTB) associated with genital mycoplasma infection in asymptomatic women.

DESIGN

Prospective cohort.

SETTING

Public and private health services in Ribeirão Preto, SP, Brazil.

POPULATION

A cohort of 1349 asymptomatic women with a singleton pregnancy at 20-25 weeks of gestation.

METHODS

Participants completed a sociodemographic and clinical history questionnaire during the prenatal visit and provided cervicovaginal samples for the evaluation of Mycoplasma hominis (Mh), Ureaplasma spp. and bacterial vaginosis (BV). For gestational outcome, information about the delivery was assessed and sPTB was defined as a birth that occurred before 37 weeks of gestation. The association between variables and the risk of sPTB was evaluated using logistic regression analysis to estimate the odds ratios (ORs).

MAIN OUTCOME MEASURES

Genital mycoplasma infection and prematurity.

RESULTS

The prevalence of sPTB and genital mycoplasma was 6.8 and 18%, respectively. The infection was not a risk factor for sPTB (aOR 0.66, 95% CI 0.32-1.35), even when Mh and Ureaplasma spp. were found together (P = 0.83). Pregnant women with genital mycoplasma infections had greater BV (P < 0.0001), but this vaginal microbiota condition was not associated with sPTB (P = 0.35). Regarding the risk factors associated with sPTB, a previous history of sPTB (aOR 12.06, 95% CI 6.21-23.43) and a cervical length of ≤2.5 cm (aOR 3.97, 95% CI 1.67-9.47) were significant.

CONCLUSIONS

Genital mycoplasma infection was not a risk factor for sPTB, even in the presence of other abnormal vaginal microbiota.

TWEETABLE ABSTRACT

Genital mycoplasma infection was not a risk for sPTB, even when associated with bacterial vaginosis (BV).

Isolation, Characterization, and Molecular Identification of Mycoplasma hominis in Females With Bacterial Vaginosis and its Association With Epidemiological Factors: A Cross-sectional Study From Isfahan Province, Iran

Background: Mycoplasma strains are frequently found in the human urogenital tract and are mainly associated with bacterial vaginosis (BV) which has several adverse outcomes including infertility, preterm delivery, and abortion. The prevalence of BV caused by Mycoplasma species could be associated with different epidemiological factors such as ethnicity, socioeconomic status, sexual activity, and age. Objective: This study aimed to investigate the prevalence of BV caused by Mycoplasma hominis and to examine its association with several epidemiological factors. Materials and Methods: A total number of 110 married, non-pregnant women in the 18-45 age range and with BV referring to the healthcare centers of Falavarjan, Isfahan province, Iran were included in this study. BV was diagnosed based on the Amsel criteria, and the polymerase chain reaction (PCR) was used for detecting M. hominis. Then, the association of several epidemiologic factors with the presence of M. hominis was examined. Results: According to the study results, 15.4% of patients (group 1, n=17) were positive for M. hominis infection, while the remaining ones (group 2, n=93) were negative for this pathogen. Statistical analyses showed no significant difference between the two groups in terms of age range, job, education level of the subjects and their husbands, history of birth delivery and abortion, number of sexual intercourses per week, daily vaginal wash, body mass index (BMI), socioeconomic status, contraception method, and positive whiff test. However, a higher prevalence of M. hominis infection was observed among the women with previous deliveries ≥2, which was significantly different from the prevalence of non-M. hominis infection. Moreover, a significant association of M. hominis infection with the pH of vaginal discharge and presence of clue cells was detected. Conclusion: An association was found between M. hominis infection and previous deliveries among the studied women, while other epidemiological factors were discovered not to be important determinants in this regard.

[Clinical implications of the genus Mycoplasma]

Dentro del género Mycoplasma, las especies que tradicionalmente se han relacionado con cuadros infecciosos han sido principalmente M. pneumoniae, M. genitalium, M. hominis o U. urealyticum. Sin embargo, existen otras muchas que están implicadas y, que muchas veces, son desconocidas para los profesionales sanitarios. El objetivo de esta revisión es identificar todas las especies del género Mycoplasma que se han aislado en el hombre y determinar su participación en la patología infecciosa humana.

Detection of sexually transmitted pathogens and co-infection with human papillomavirus in women residing in rural Eastern Cape, South Africa

Background

South African women of reproductive age have a high burden of sexually transmitted infections (STIs), including human papillomavirus (HPV) infection. However, there is limited information on the prevalence of sexually transmitted pathogens in women from rural Eastern Cape Province, South Africa. The study aims at determining the prevalence of sexually transmitted pathogens and co-infection with high-risk (HR) HPV among women from rural Eastern Cape Province, South Africa.

Methods

A total of 205 cervical specimens were collected from women aged ≥ 30 years from a rural community-based clinic. The samples were tested for a panel of pathogenic STIs [Chlamydia trachomatis (serovars A-K & L1-L3), Haemophilus ducreyi, Herpes Simplex Virus (Types 1 & 2), Neisseria gonorrhoeae, Treponema pallidum, Trichomonas vaginalis (TV), and pathobionts [Mycoplasma genitalium (MG), Mycoplasma hominis (MH) and Ureaplasma spp. (UP)] using a multiplex PCR STD direct flow chip assay through a manual Hybrispot platform (Master Diagnostica, Granada, Spain). HR-HPV detection was performed by Hybrid Capture-2 assay.

Results

High-risk HPV prevalence was 32.2% (66/205) and HIV-1 prevalence was 38.5% (79/205). The overall prevalence of six pathogenic STIs was 22.9% (47/205), with TV having the highest prevalence (15.6%; 32/205). UP (70.2%, 144/205) and MH (36.6%, 75/205) were the most frequently detected pathobionts. Co-infection with ≥ 2 pathogens pathobionts was observed among 52.7% (108/205) participants. Of the six pathogenic STIs, three participants had more than one STI (1.46%) with the presence of MH and UP. HSV-2 (OR: 4.17, CI [1.184-14.690]) and HIV infection (OR: 2.11, CI [1.145-3.873]) were independent STIs associated with HR-HPV infection.

Conclusions

The high prevalence of pathogenic STIs underscores the need to improve syndromic management policy by implementing effective strategies of prevention, screening tests, and management. HSV-2 and HIV positive remain strongly associated with HR-HPV infection.

Are Mycoplasma hominis, Ureaplasma urealyticum and Ureaplasma parvum associated with specific genital symptoms and clinical signs in non-pregnant women?

BACKGROUND

There is limited evidence supporting an association between Mycoplasma hominis, Ureaplasma urealyticum and Ureaplasma parvum and symptoms or disease in non-pregnant women. However, testing and reporting of these organisms frequently occurs, in-part due to their inclusion in multiplex-PCR assays for sexually transmitted infection (STI) detection. We investigated if M. hominis, U. urealyticum and U. parvum were associated with symptoms and/or signs in non-pregnant women attending a sexual health service.

METHODS

Eligible women attending Melbourne Sexual Health Centre completed a questionnaire regarding sexual practices and symptoms. Symptomatic women underwent examination. Women were assessed for bacterial vaginosis (BV) and vulvovaginal candidiasis (VVC), and tested for M. hominis, U. urealyticum and U. parvum, and four non-viral STIs using a commercial multiplex-PCR.

RESULTS

1,272 women were analysed. After adjusting for STIs and VVC, M. hominis was associated with abnormal vaginal discharge (aOR=2.70, 95%CI:1.92-3.79), vaginal malodour (aOR=4.27, 95%CI:3.08-5.91), vaginal pH>4.5 (aOR=4.27, 95%CI:3.22-5.66) and presence of clue cells (aOR=8.08, 95%CI:5.68-11.48). Ureaplasma spp. were not associated with symptoms/signs. BV was strongly associated with M. hominis (aOR=8.01, 95%CI:5.99-10.71), but was not associated with either Ureaplasma spp. In stratified analyses, M. hominis was associated with self-reported vaginal malodour and clinician-recorded vaginal discharge in women with BV, but not with symptoms/signs in women without BV.

CONCLUSION

Only M. hominis was associated with symptoms/signs, and these were manifestations of BV. Importantly, M. hominis was not associated with symptoms/signs in women without BV. These findings do not support routine testing for M. hominis, U. urealyticum and U. parvum in non-pregnant women.

Gardnerella and vaginal health: the truth is out there

The human vagina is a dynamic ecosystem in which homeostasis depends on mutually beneficial interactions between the host and their microorganisms. However, the vaginal ecosystem can be thrown off balance by a wide variety of factors. Bacterial vaginosis (BV) is the most common vaginal infection in women of childbearing age but its etiology is not yet fully understood, with different controversial theories being raised over the years. What is generally accepted is that BV is often characterized by a shift in the composition of the normal vaginal microbiota, from a Lactobacillus species dominated microbiota to a mixture of anaerobic and facultative anaerobic bacteria. During BV, a polymicrobial biofilm develops in the vaginal microenvironment, being mainly composed of Gardnerella species. The interactions between vaginal microorganisms are thought to play a pivotal role in the shift from health to disease and might also increase the risk of sexually transmitted infections acquisition. Here, we review the current knowledge regarding the specific interactions that occur in the vaginal niche and discuss mechanisms by which these interactions might be mediated. Furthermore, we discuss the importance of novel strategies to fight chronic vaginal infections.

Mycoplasmas-Host Interaction: Mechanisms of Inflammation and Association with Cellular Transformation

Mycoplasmas are the smallest and simplest self-replicating prokaryotes. Located everywhere in nature, they are widespread as parasites of humans, mammals, reptiles, fish, arthropods, and plants. They usually exhibiting organ and tissue specificity. Mycoplasmas belong to the class named Mollicutes (mollis = soft and cutis = skin, in Latin), and their small size and absence of a cell wall contribute to distinguish them from other bacteria. Mycoplasma species are found both outside the cells as membrane surface parasites and inside the cells, where they become intracellular residents as "silent parasites". In humans, some Mycoplasma species are found as commensal inhabitants, while others have a significant impact on the cellular metabolism and physiology. Mollicutes lack typical bacterial PAMPs (e.g., lipoteichoic acid, flagellin, and some lipopolysaccharides) and consequently the exact molecular mechanisms of Mycoplasmas' recognition by the cells of the immune system is the subjects of several researches for its pathogenic implications. It is well known that several strains of Mycoplasma suppress the transcriptional activity of p53, resulting in reduced apoptosis of damaged cells. In addition, some Mycoplasmas were reported to have oncogenic potential since they demonstrated not just accumulation of abnormalities but also phenotypic changes of the cells. Aim of this review is to provide an update of the current literature that implicates Mycoplasmas in triggering inflammation and altering critical cellular pathways, thus providing a better insight into potential mechanisms of cellular transformation.

MYCO WELL D-ONE detection of Ureaplasma spp. and Mycoplasma hominis in sexual health patients in Wales

The genital mycoplasmas are a unique group of inherently antibiotic-resistant sexually transmitted bacteria, often associated with non-gonococcal urethritis and bacterial vaginosis. The MYCO WELL D-ONE is a culture-based assay that aims to detect these organisms whilst concurrently screening them for antibiotic resistance. Urine and/or swabs from 856 informed and consented participants attending Welsh sexual health clinics were subjected to MYCO WELL D-ONE analysis, alongside qPCR and culture titration methodologies to determine sensitivity, specificity, PPV, NPV and accuracy. Resistance was confirmed by CLSI-compliant susceptibility testing and genetic mechanisms determined. The MYCO WELL D-ONE displayed a sensitivity and specificity of 91.98% and 96.44% for the detection of Ureaplasma spp., with sensitivity and specificity values of 78.23% and 98.84% for Mycoplasma hominis, compared with qPCR. Swabs harboured significantly greater bacterial loads than urine samples for both Ureaplasma spp. and M. hominis. Levofloxacin resistance rates, mediated by Ser83Leu mutation in ParC, for Ureaplasma spp. were 0.54%. Tetracycline resistance rates, mediated by tet(M), were 0.54% and 2% for Ureaplasma spp. and M. hominis, respectively; sequence analysis of tet(M)-positive Ureaplasma spp. and M. hominis strains isolated from a single individual confirmed separate resistance gene origins. The MYCO WELL D-ONE is a sensitive and specific assay for the detection of Ureaplasma spp. and M. hominis in genitourinary medicine samples, facilitating the accurate detection of these organisms within low-technology environments. While good for antibiotic resistance screening, accurate confirmation by MIC determination or molecular methods are required, and more optimally performed on urine samples.

Recent clinical relevance of mono-genital colonization/infection by Ureaplasma parvum

Ureaplasma parvum is the most prevalent genital mycoplasma in women of childbearing age. There is debate around the relevance of its presence in male or female genitals for disease development and as a cofactor. The objective of this study was to determine the prevalence of colonization/infection by U. parvum and its possible relationship with reproductive tract infections. We retrospectively analyzed the presence of U. parvum in patients referred by specialist clinicians for suspicion of genitourinary tract infection. U. parvum was detected in 23.8% of samples, significantly more frequently in females (39.9%) than in males (6%). Among the males, U. parvum was found alone in 68.4% of episodes, with Ct < 30. Among the females, U. parvum was detected in 88.6% of cases, with Ct < 30, including 22 cases with premature rupture of membranes and 6 cases with threat of preterm labor. Co-infection was significantly more frequent in females (62.6%) than in males (31.6%). Given the high prevalence of U. parvum as sole isolate in males and females with genitourinary symptoms, it should be considered in the diagnosis and treatment of genital infections, although its pathogenic role in some diseases has not been fully elucidated.

Impact of Symbiosis Between Trichomonas vaginalis and Mycoplasma hominis on Vaginal Dysbiosis: A Mini Review

The protozoon Trichomonas vaginalis is responsible for trichomoniasis, a common sexually transmitted infection associated with an increased risk of HIV infection and adverse pregnancy outcomes. The protozoon has the surprising ability to establish a symbiotic relationship with other microorganisms. In fact, most T.vaginalis isolates intracellularly host the vaginal bacterium Mycoplasma hominis and can harbor up to four dsRNA viruses. Moreover, a novel Mycoplasma species named Ca. Mycoplasma girerdii has been recently described as associated with trichomonad cells. Trichomonas vaginalis colonizes the human vagina and its presence causes profound alterations of the resident microbiota, leading to dysbiosis. In healthy women, vaginal microbiota is characterized by the presence of a complex population of aerobic and anaerobic microorganisms living in a physiologically dynamic system dominated by bacteria of the genera Lactobacillus. The most common microbial vaginal imbalance is bacterial vaginosis, a polymicrobial disease associated with several adverse reproductive outcomes and increased risk of HIV infection. Here, we review the current knowledge regarding the interactions between both T.vaginalis and M.hominis and the vaginal microbiota, and we discuss the possibility of a cooperation between T.vaginalis and its symbionts in the development of vaginal dysbiosis.

Roles of the vagina and the vaginal microbiota in urinary tract infection: evidence from clinical correlations and experimental models

Mounting evidence indicates that the vagina can harbor uropathogenic bacteria. Here, we consider three roles played by the vagina and its bacterial inhabitants in urinary tract infection (UTI) and urinary health. First, the vagina can serve as a reservoir for Escherichia coli, the most common cause of UTI, and other recognized uropathogens. Second, several vaginal bacterial species are frequently detected upon urine culture but are underappreciated as uropathogens, and other vaginal species are likely under-reported because of their fastidious nature. Third, some vaginal bacteria that are not widely viewed as uropathogens can transit briefly in the urinary tract, cause injury or immunomodulation, and shift the balance of host-pathogen interactions to influence the outcomes of uropathogenesis. This chapter describes the current literature in these three areas and summarizes the impact of the vaginal microbiota on susceptibility to UTI and other urologic conditions.

Diversity of vaginal microbiome and metabolome during genital infections

We characterized the vaginal ecosystem during common infections of the female genital tract, as vulvovaginal candidiasis (VVC, n = 18) and Chlamydia trachomatis infection (CT, n = 20), recruiting healthy (HC, n = 21) and bacterial vaginosis-affected (BV, n = 20) women as references of eubiosis and dysbiosis. The profiles of the vaginal microbiome and metabolome were studied in 79 reproductive-aged women, by means of next generation sequencing and proton based-nuclear magnetic resonance spectroscopy. Lactobacillus genus was profoundly depleted in all the genital infections herein considered, and species-level analysis revealed that healthy vaginal microbiome was dominated by L. crispatus. In the shift from HC to CT, VVC, and BV, L. crispatus was progressively replaced by L. iners. CT infection and VVC, as well as BV condition, were mainly characterised by anaerobe genera, e.g. Gardnerella, Prevotella, Megasphaera, Roseburia and Atopobium. The changes in the bacterial communities occurring during the genital infections resulted in significant alterations in the vaginal metabolites composition, being the decrease of lactate a common marker of all the pathological conditions. In conclusion, according to the taxonomic and metabolomics analysis, we found that each of the four conditions is characterized by a peculiar vaginal microbiome/metabolome fingerprint.

Molecular epidemiology of bacterial vaginosis and its association with genital micro-organisms in asymptomatic women

Introduction. Bacterial vaginosis (BV) is dysbiosis associated with an increased risk of several sexually transmitted infections. It is primarily diagnosed via Gram staining, although molecular analyses have presented higher diagnostic accuracy.Aim. This study aimed to evaluate the molecular epidemiology of BV in asymptomatic women to determine its association with several commensal and pathogenic micro-organisms of the genitalia.Methodology. The prevalence of BV was investigated through semiquantitative assessment of 201 women recruited during their routine gynaecological inspection at an outpatient clinic in Tabasco, Mexico.Results. Women with BV showed an increased prevalence of Chlamydia trachomatis (P=0.021) and Mycoplasma hominis (P=0.001). Of the BV-associated micro-organisms, Gardnerella vaginalis was significantly associated with C. trachomatis (P=0.005) and/or Ureaplasma parvum (P=0.003), whereas Atopobium vaginae and Megasphaera type 1 correlated significantly with Mycoplasma hominis (P=0.001). No significant association was observed between human papillomavirus (HPV) infection and BV, although there was increased prevalence of HPV59, HPV73, HPV52 and HPV58 in women displaying cervical cytological abnormalities.Conclusion. Identification of BV-associated micro-organisms via molecular analysis may help to distinguish recurrent cases from new infections and identify micro-organisms potentially associated with pharmacological resistance.

Mycoplasma hominis Infections Transmitted Through Amniotic Tissue Product

Background

Mycoplasma hominis is a commensal genitourinary tract organism that can cause infections outside the genitourinary tract. We investigated a cluster of M. hominis surgical site infections in patients who underwent spine surgery, all associated with amniotic tissue linked to a common donor.

Methods

Laboratory tests of tissue product from the donor, including culture, quantitative real-time polymerase chain reaction (qPCR), and whole-genome sequencing were performed. Use of this amniotic tissue product was reviewed. A multistate investigation to identify additional cases and locate any unused products was conducted.

Results

Twenty-seven tissue product vials from a donor were distributed to facilities in 7 states; at least 20 vials from this donor were used in 14 patients. Of these, 4 of 14 (29%) developed surgical site infections, including 2 M. hominis infections. Mycoplasma hominis was detected by culture and qPCR in 2 unused vials from the donor. Sequencing indicated >99% similarity between patient and unopened vial isolates. For 5 of 27 (19%) vials, the final disposition could not be confirmed.

Conclusions

Mycoplasma hominis was transmitted through amniotic tissue from a single donor to 2 recipients. Current routine donor screening and product testing does not detect all potential pathogens. Clinicians should be aware that M. hominis can cause surgical site infections, and may not be detected by routine clinical cultures. The lack of a standardized system to track tissue products in healthcare facilities limits the ability of public health agencies to respond to outbreaks and investigate other adverse events associated with these products.

Unveiling the role of Gardnerella vaginalis in polymicrobial Bacterial Vaginosis biofilms: the impact of other vaginal pathogens living as neighbors

Bacterial vaginosis (BV) is characterized by a highly structured polymicrobial biofilm, which is strongly adhered to the vaginal epithelium and primarily consists of the bacterium Gardnerella vaginalis. However, despite the presence of other BV-associated bacteria, little is known regarding the impact of other species on BV development. To gain insight into BV progress, we analyzed the ecological interactions between G. vaginalis and 15 BV-associated microorganisms using a dual-species biofilm model. Bacterial populations were quantified using a validated peptide nucleic acid fluorescence in situ hybridization approach. Furthermore, biofilm structure was analyzed by confocal laser scanning microscopy. In addition, bacterial coaggregation ability was determined as well as the expression of key virulence genes. Remarkably, our results revealed distinct biofilm structures between each bacterial consortium, leading to at least three unique dual-species biofilm morphotypes. Furthermore, our transcriptomic findings seem to indicate that Enterococcus faecalis and Actinomyces neuii had a higher impact on the enhancement of G. vaginalis virulence, while the other tested species had a lower or no impact on G. vaginalis virulence. This study casts a new light on how BV-associated species can modulate the virulence aspects of G. vaginalis, contributing to a better understanding of the development of BV-associated biofilms.

An update on the role of Atopobium vaginae in bacterial vaginosis: what to consider when choosing a treatment? A mini review

INTRODUCTION

Bacterial vaginosis (BV) is the most common vaginal disorder in reproductive-age women. The condition is characterised by the replacement of a healthy, lactobacilli-dominated vaginal microbiota by anaerobic and facultative anaerobic bacteria. BV increases the risk of acquisition of STIs and is associated with pregnancy complications. Although the composition of the bacteria in BV varies between individuals, there are some species such as Gardnerella, Atopobium, Mycoplasma, Snethia, Megasphera, Dialister, etc., that are found most frequently.

MATERIAL AND METHODS

Literature research to the importance of Atopobium vaginae in BV and treatment options.

RESULTS

Atopobium (A.) vaginae is an important component of the complex abnormal vaginal flora in BV; even though A. vaginae, like Gardnerella vaginalis, has also been detected in the normal flora, it is much more common in BV patients. A. vaginae has been shown to play an important role in the pathophysiology of BV and is thought to be at least a partial cause of the known negative sequelae. The presence of A. vaginae in the BV-associated biofilms and its resistance to some antimicrobial substances has been described - this seems to have a major impact on treatment outcome.

CONCLUSION

Current scientific data demonstrate that dequalinium chloride (Fluomycin^®) is one of the valid therapeutic options for BV treatment, since it displays a broad antimicrobial spectrum against relevant vaginal pathogens, especially against G. vaginalis and A. vaginae, without having safety concerns.

Impact of asymptomatic genital tract infections on in vitro Fertilization (IVF) outcome

Background

Infertility is estimated to affect approximately 9–30% of reproductive-aged couples. Several conditions involving one or both partners may contribute to infertility. The aim of this study is to evaluate the role of asymptomatic genital tract infections in the outcome of In Vitro Fertilization (IVF) in couples with infertility.

Methods

A total of 285 infertile couples were enrolled in the study. Vaginal/endocervical swabs and semen samples were collected and subjected to microbiological analysis. Spermiograms were carried out on semen specimens, and lactobacilli were quantified in vaginal swabs. Data were associated with IVF results and analysed by using non parametric tests and multivariate analysis.

Results

Microbiological analysis showed that 46.3% of couples presented with an asymptomatic genital tract infection. Spermiogram results showed a significantly diminished motility of sperm cells in samples positive to microbiological testing compared to negative specimens. Enterococcus faecalis was the most prevalent species (11.6%) in positive semen samples and was found to negatively affect both sperm morphology (p = 0.026) and motility (p = 0.003). Analysis of genital swabs from females showed that the presence of E. faecalis (p<0.0001), Escherichia coli (p = 0.0123), Streptococcus agalactiae (p<0.0001), and Gardnerella vaginalis (p = 0.0003) was significantly associated to reduced levels of vaginal lactobacilli. Association of microbiological data with IVF outcome showed that 85.7% of IVF+ couples was microbiologically negative, while IVF was successful in just 7.5% of couples infected with E. faecalis and/or U. urealyticum and/or M. hominis (p = 0.02).

Conclusions

The results show the negative impact of E. faecalis on sperm quality and the association of definite bacterial pathogens with reduced levels of vaginal lactobacilli. The presence of E. faecalis and/or U. urealyticum and/or M. hominis in genital samples of infertile couples is predictive for a negative outcome of IVF.

Prevalence of Ureaplasma spp. and Mycoplasma hominis in healthy women and patients with flora alterations

The objective was to estimate the prevalence of Mycoplasma hominis, Ureaplasma parvum, and Ureaplasma urealyticum in healthy women and patients with altered vaginal microflora. Vaginal samples from 2594 unselected female patients were divided into normal, bacterial vaginosis (BV), and aerobic vaginitis (AV) groups and tested for U. parvum, U. urealyticum and M. hominis. Normal flora was detected in 1773 patients (68.4%), BV in 754 patients (29.1%), and AV in 67 patients (2.6%). In the control group, 771 (43.5%) patients were U. parvum positive, 104 (5.9%) were U. urealyticum positive, and 158 (8.9%) were M. hominis positive. In the BV group, those bacteria were detected in 452 (59.9%), 102 (13.5%), and 202 (26.8%) patients, respectively (P < 0.001); in the AV group, those were detected in 16 (23.9%), 3 (4.5%), and 4 (6.0%) patients, respectively (P < 0.001; 0.63 and 0.40, respectively). This study demonstrated that mycoplasmas may be a marker or a symbiont of the BV flora but not AV flora.

Cross-feeding modulates antibiotic tolerance in bacterial communities

Microbes frequently rely on metabolites excreted by other bacterial species, but little is known about how this cross-feeding influences the effect of antibiotics. We hypothesized that when species rely on each other for essential metabolites, the minimum inhibitory concentration (MIC) for all species will drop to that of the “weakest link”—the species least resistant in monoculture. We tested this hypothesis in an obligate cross-feeding system that was engineered between Escherichia coli, Salmonella enterica, and Methylobacterium extorquens. The effect of tetracycline and ampicillin were tested on both liquid and solid media. In all cases, resistant species were inhibited at significantly lower antibiotic concentrations in the cross-feeding community than in monoculture or a competitive community. However, deviation from the “weakest link” hypothesis was also observed in cross-feeding communities apparently as result of changes in the timing of growth and cross-protection. Comparable results were also observed in a clinically relevant system involving facultative cross-feeding between Pseudomonas aeruginosa and an anaerobic consortium found in the lungs of cystic fibrosis patients. P. aeruginosa was inhibited by lower concentrations of ampicillin when cross-feeding than when grown in isolation. These results suggest that cross-feeding significantly alters tolerance to antibiotics in a variety of systems.

Should we be testing for urogenital Mycoplasma hominis, Ureaplasma parvum and Ureaplasma urealyticum in men and women? - a position statement from the European STI Guidelines Editorial Board

At present, we have no evidence that we are doing more good than harm detecting and subsequently treating Mycoplasma hominis, Ureaplasma parvum and Ureaplasma urealyticum colonizations/infections. Consequently, routine testing and treatment of asymptomatic or symptomatic men and women for M. hominis, U. urealyticum and U. parvum are not recommended. Asymptomatic carriage of these bacteria is common, and the majority of individuals do not develop any disease. Although U. urealyticum has been associated with urethritis in men, it is probably not causal unless a high load is present (likely carriage in 40-80% of detected cases). The extensive testing, detection and subsequent antimicrobial treatment of these bacteria performed in some settings may result in the selection of antimicrobial resistance, in these bacteria, 'true' STI agents, as well as in the general microbiota, and substantial economic cost for society and individuals, particularly women. The commercialization of many particularly multiplex PCR assays detecting traditional non-viral STIs together with M. hominis, U. parvum and/or U. urealyticum has worsened this situation. Thus, routine screening of asymptomatic men and women or routine testing of symptomatic individuals for M. hominis, U. urealyticum and U. parvum is not recommended. If testing of men with symptomatic urethritis is undertaken, traditional STI urethritis agents such as Neisseria gonorrhoeae, Chlamydia trachomatis, M. genitalium and, in settings where relevant, Trichomonas vaginalis should be excluded prior to U. urealyticum testing and quantitative species-specific molecular diagnostic tests should be used. Only men with high U. urealyticum load should be considered for treatment; however, appropriate evidence for effective treatment regimens is lacking. In symptomatic women, bacterial vaginosis (BV) should always be tested for and treated if detected.

Microbiota-based analysis reveals specific bacterial traits and a novel strategy for the diagnosis of infectious infertility

Tubal factor infertility (TFI) accounts for more than 30% of the cases of female infertility and mostly resides from an inflammatory process triggered by an infection. Clinical appearances largely differ, and very often infections are not recognized or remain completely asymptomatic over time. Here, we characterized the microbial pattern in females diagnosed with infectious infertility (ININF) in comparison to females with non-infectious infertility (nININF), female sex workers (FSW) and healthy controls (fertile). Females diagnosed with infectious infertility differed significantly in the seroprevalence of IgG antibodies against the C. trachomatis proteins MOMP, OMP2, CPAF and HSP60 when compared to fertile females. Microbiota analysis using 16S amplicon sequencing of cervical swabs revealed significant differences between ININF and fertile controls in the relative read count of Gardnerella (10.08% vs. 5.43%). Alpha diversity varies among groups, which are characterized by community state types including Lactobacillus-dominated communities in fertile females, an increase in diversity in all the other groups and Gardnerella-dominated communities occurring more often in ININF. While all single parameters did not allow predicting infections as the cause of infertility, including C. trachomatis IgG/IgA status together with 16S rRNA gene analysis of the ten most frequent taxa a total of 93.8% of the females were correctly classified. Further studies are needed to unravel the impact of the cervical microbiota in the pathogenesis of infectious infertility and its potential for identifying females at risk earlier in life.

Prevalence and antimicrobial susceptibility of Ureaplasma species and Mycoplasma hominis in Greek female outpatients, 2012-2016

Mycoplasma hominis and Ureaplasma species are opportunistic pathogens associated with urogenital infections, complications during pregnancy and postpartum infections. Appropriate empirical antimicrobial treatment is necessary to achieve an optimal therapeutic outcome. This study evaluated the prevalence and the antimicrobial susceptibility of Mycoplasma hominis and Ureaplasma spp. isolated from 1,008 endocervical samples of outpatients in Crete, Greece, during a five-year period (2012-2016), using the commercially available Mycoview kit (Zeakon diagnostics, France). Ureaplasma spp. was isolated from 116 patients (11.5%), M. hominis from 6 (0.6%), while coinfection with both mycoplasmas was demonstrated in 17 (1.7%). All Ureaplasma strains were susceptible to josamycin and doxycycline. Doxycycline, minocycline and ofloxacin were the most potent antibiotics against M. hominis. Docycycline was proved the most active and is still the drug of choice for the treatment of genital mycoplasma infections. Local surveillance to monitor changes in antimicrobial susceptibilities is necessary to guide treatment strategies.

Prevalence of bacterial vaginosis in Portuguese pregnant women and vaginal colonization by Gardnerella vaginalis

Background

We aimed to determine the prevalence of vaginal colonization by Gardnerella vaginalis and of bacterial vaginosis (BV) in Portuguese pregnant women, and to identify risk factors for BV and G. vaginalis colonization in pregnancy.

Methods

A cross-sectional study was conducted among pregnant women aged ≥ 18 years who were attending in two public hospitals of the Northwest region of Portugal. Epidemiological data was collected by anonymous questionnaire. BV was diagnosed by Nugent criteria and G. vaginalis presence was identified by polymerase chain reaction. Crude associations between the study variables and BV or G. vaginalis colonization were quantified by odds ratios (ORs) and their 95% confidence intervals (CIs).

Results

The prevalences of BV and of G. vaginalis colonization among Portuguese pregnant women were 3.88% and 67.48%, respectively. Previous preterm delivery and colonization by G. vaginalis were factors with very high OR, but only statistically significant for a 90% CI. Conversely, higher rates of G. vaginalis colonization were found in women with basic educational level (OR = 2.77, 95% CI [1.33–5.78]), during the second trimester of pregnancy (OR = 6.12, 95% CI [1.80–20.85]) and with BV flora (OR = 8.73, 95% CI [0.50–153.60]).

Discussion

Despite the lower number of women with BV, prevalence ratios and association with risk factors were similar to recent European studies. However, the percentage of healthy women colonized by G. vaginalis was significantly higher than many previous studies, confirming that G. vaginalis colonization does not always lead to BV development.

Eve's garden: myths, legends and secrets unmasked

This special issue of Research in Microbiology aims to provide some insights in one of women's most fascinating interacting microbial communities: the vaginal microbiome. Even in the 21st century, with many advanced methods at hand, the definition of the healthy vaginal microbiome remains under debate. The interest in studying the dysbiosis of the vaginal microbiome is increasing and goes well beyond the study of bacterial vaginosis. The selection of contributions in this issue summarizes what is currently known in terms of inter- and intra-microorganisms interaction as well as the virulence factors that some of them may deploy.

Prevalence and distribution of Gardnerella vaginalis subgroups in women with and without bacterial vaginosis

BACKGROUND

Bacterial vaginosis (BV) is one of the leading causes of vaginal complaints among women of childbearing age. The role of Gardnerella vaginalis remains controversial due to its presence in healthy and BV-type vaginal microflora. The phenotypic and genotypic heterogeneity of G. vaginalis suggested the existence of strain variants linked with different health conditions. We sought to analyze prevalence and distribution of G. vaginalis subgroups (clades) in BV-positive (n = 29), partial BV (n = 27), and BV-negative (n = 53) vaginal samples from Lithuanian women.

METHODS

Vaginal samples were characterized by Amsel criteria and the Nugent method. Bacterial signatures characteristic of BV and concomitant infections were identified by culture and PCR. Using singleplex PCR assays, G. vaginalis subgroups were identified in 109 noncultured vaginal specimens by targeting clade-specific genes. Isolated G. vaginalis clinical strains were subtyped and the presence of the sialidase coding gene was detected by PCR. Data analysis was performed using GraphPad Prism statistical software.

RESULTS

G. vaginalis was found in 87% of women without BV. Clade 4 was most frequently detected (79.4%), followed by clade 1 (63.7%), clade 2 (42.2%), and clade 3 (15.7%). Multi-clade G. vaginalis communities showed a positive association with Nugent score (NS) ≥ 4 (OR 3.64; 95% CI 1.48-8.91; p = 0.005). Clade 1 and clade 2 were statistically significantly more common in samples with NS 7-10 (OR 4.69; 95% CI 1.38-15.88; p = 0.01 and OR 6.26; 95% CI 2.20-17.81; p ≤ 0.001, respectively). Clade 3 and clade 4 showed no association with high NS (OR 0.88; 95% CI 0.26-3.04; p = 1.00 and OR 1.31; 95% CI 0.39-4.41; p = 0.767, respectively). The gene coding for sialidase was detected in all isolates of clade 1 and clade 2, but not in clade 4 isolates.

CONCLUSIONS

We showed an association between the microbial state of vaginal microflora and specific subgroups of G. vaginalis, the distribution of which may determine the clinical manifestation of BV. The frequent detection of clade 4 in the BV-negative samples might be due its lack of the gene coding for sialidase.

Mollicutes in vaginal microbiology: Mycoplasma hominis, Ureaplasma urealyticum, Ureaplasma parvum and Mycoplasma genitalium

Mycoplasma hominis was isolated in 1937 from the human genital tract, followed 17 years later by Ureaplasma urealyticum and 27 years after that by Mycoplasma genitalium. The first two proved relatively easy to culture but the latter required a polymerase chain reaction assay for further studies. In sexually mature women, M. hominis may be found in the vagina/cervix of about 20-50%, ureaplasmas in 40-80% and M. genitalium in 0-5%. Some heterogeneity has been found among strains of all these species, sufficient to divide ureaplasmas into two species, namely U. urealyticum and Ureaplasma parvum. Studies in female mice show that sex hormones have a profound influence on colonization, multiplication and persistence of mycoplasmas/ureaplasmas in the genital tract and provoke the question, unanswered, of whether there is such an effect in the human tract. In women, there is no evidence that any of the mycoplasmal species stimulate an inflammatory vaginitis. M. hominis organisms increase hugely in number in the case of bacterial vaginosis (BV), and to a lesser extent so do ureaplasmas. Despite this, they have not been incriminated as a sole cause of BV. Evidence for the involvement of M. genitalium remains controversial. The strong association of BV with preterm birth raises the possibility that the genital mycoplasmas might play a part, but assurance that any do will be difficult to obtain. Detailed examination of the vaginal microbiome has not yet provided an answer.

Gardnerella vaginalis and Mollicute detection in rectal swabs from men who have sex with men

The numbers of rectal sexually transmitted infections are on the rise especially among men who have sex with men. Males from men who have sex with men population are encouraged to send a rectal swab to the laboratory for sexually transmitted infection screening at their visit to the Genitourinary Medicine Clinic. In healthy asymptomatic males, the range of pathogens tested is limited therefore other pathogens may be left untreated allowing infections to persist among sexual partners. Molecular techniques have revolutionarised sexually transmitted infection testing enabling the detection of previously difficult-to-culture pathogens in extra-genital sites and have increased the evidence base for their clinical significance. The present study tests 107 rectal swabs from men who have sex with men negative for Chlamydia trachomatis and Neisseria gonorrhoeae against quantitative polymerase chain reaction (qPCR) assays targeting five common sexually transmitted bacteria which include Mycoplasma genitalium, Mycoplasma hominis, Ureaplasma urealyticum, Ureaplasma parvum and Gardnerella vaginalis. The pathogenic role of these five bacteria in men who have sex with men is currently unknown. Amongst the 107 patients, a positive qPCR was obtained respectively for G. vaginalis 89 (83.2%); U. urealyticum 26 (24.3%); M. hominis 26 (24.3%); M. genitalium 10 (9.3%) and U. parvum 5 (4.7%). Bacterial loads in single and co-infections were compared for each organism. G. vaginalis and M. hominis loads were significantly ( p = 0.007 and p = 0.005, respectively) higher when co-infecting with at least one other organism. Amongst co-infections, the loads of each organism were assessed to determine possible synergies. G. vaginalis and M. hominis displayed a synergistic pattern ( r = 0.51; p = 0.02) which is in keeping with a similar synergy detected previously in the vagina of women with bacterial vaginosis. This study outlines that potential significant infections are being missed in men who have sex with men population; however, further research is warranted to confirm a pathogenesis in the rectal mucosa before routine screening can be introduced to clinical settings.

Bacterial vaginosis: a critical analysis of current knowledge

Bacterial vaginosis (BV), the change from a Lactobacillus-dominant vaginal microbiota to an anaerobic and facultative bacterial dominance, is associated with pathological sequelae. In many BV-positive women their microbiota is in fact normal and unrelated to pathology. Whether or not the dominance of BV-associated bacteria persists depends upon interactions between host and bacterial factors. Inconsistencies in diagnosis and erroneous associations with pathology may be due to a failure to differentiate between sub-populations of women. It is only in those women with a BV diagnosis in which the identified bacteria are atypical and persist that BV may be a clinical problem requiring intervention.

TWEETABLE ABSTRACT

Improved diagnosis of bacterial vaginosis is needed to accurately determine its role in pathology.