Mycoplasma genitalium Provokes Seminal Inflammation among Infertile Males.

The impact of sexually transmitted infections (STI) on male fertility is controversial. Aims: To investigate the prevalence of urethritis-associated STIs (chlamydia, gonorrhoeae, Mycoplasma genitalium, trichomoniasis) among infertile males; to analyze the effect of STIs on semen parameters and blood PSA. Case-control study. Study group (n = 2000): males with fertility problems or desire for fertility check. Control group (n = 248): male partners of pregnant women. Analyses: polymerase chain reaction for STI, seminal interleukin 6 (IL-6), semen and fractionated urine, blood analyses (PSA, reproductive hormones). The prevalence of M. genitalium and chlamydia in the study group was 1.1% and 1.2%, respectively. The prevalence of chlamydia in the control group was 1.6%, while there were no M. genitalium cases. No cases with gonorrhoeae or trichomoniasis or combined infections were observed in neither group. There was a higher seminal concentration of neutrophils and IL-6 among M. genitalium positives compared with STI negatives. There was a trend toward a lower total count of spermatozoa and progressive motility among STI positives. No impact of STIs on PSA was found. The prevalence of STIs among infertile males is low. M. genitalium is associated with seminal inflammation. The impact of STIs on semen parameters deserves further investigations.

Identification of histone H2B as a potential receptor for Mycoplasma genitalium protein of adhesion.

Mycoplasma genitalium, the smallest prokaryotic microorganism capable of independent replication, is increasingly recognized as a sexually transmitted pathogen. M. genitalium protein of adhesion (MgPa) plays a pivotal role in the process of M. genitalium adhesion to host cells. We previously identified cyclophilin A as a cellular receptor of MgPa using the virus overlay protein binding assay (VOPBA) together with liquid chromatography-mass spectrometry (LC-MS). In the current study, we have evaluated H2B as an alternative cellular receptor for MgPa since H2B was assigned the second higher score as a potential binding partner of MgPa in the VOPBA and LC-MS screen. It was found that recombinant MgPa specifically bind to H2B both in the SV-HUC-1 cell membrane and in form of a recombinant protein. H2B was detected throughout the SV-HUC-1 cells, including the cytoplasmic membrane, cytosol and nucleus. Importantly, H2B partially inhibited the adhesion of M. genitalium to SV-HUC-1 cells. Finally, H2B was both co-precipitated with recombinant MgPa and co-localized with M. genitalium and recombinant MgPa in SV-HUC-1 cells. The above observations suggest that H2B may act as a potential cellular receptor of MgPa for mediating M. genitalium adhesion to host cells.

Mycoplasma genitalium and M. pneumoniae Regulate a Distinct Set of Protein-Coding Genes in Epithelial Cells.

Mycoplasma genitalium and M. pneumoniae are two significant mycoplasmas that infect the urogenital and respiratory tracts of humans. Despite distinct tissue tropisms, they both have similar pathogenic mechanisms and infect/invade epithelial cells in the respective regions and persist within these cells. However, the pathogenic mechanisms of these species in terms of bacterium-host interactions are poorly understood. To gain insights on this, we infected HeLa cells independently with M. genitalium and M. pneumoniae and assessed gene expression by whole transcriptome sequencing (RNA-seq) approach. The results revealed that HeLa cells respond to M. genitalium and M. pneumoniae differently by regulating various protein-coding genes. Though there is a significant overlap between the genes regulated by these species, many of the differentially expressed genes were specific to each species. KEGG pathway and signaling network analyses revealed that the genes specific to M. genitalium are more related to cellular processes. In contrast, the genes specific to M. pneumoniae infection are correlated with immune response and inflammation, possibly suggesting that M. pneumoniae has some inherent ability to modulate host immune pathways.

The Impact of Selected Bacterial Sexually Transmitted Diseases on Pregnancy and Female Fertility.

Sexually transmitted infections (STIs) caused by Neisseria gonorrhoeae, Chlamydia trachomatis and Mycoplasma genitalium are a common cause of pelvic inflammatory disease (PID) which can lead to tubal factor infertility (TFI). TFI is one of the most common causes of infertility, accounting for 30% of female fertility problems. STIs can also have an impact on pregnancy, leading to adverse pregnancy outcomes. Escalating antibiotic resistance in Neisseria gonorrhoeae and Mycoplasma genitalium represents a significant problem and can be therapeutically challenging. We present a comprehensive review of the current treatment options, as well as the molecular approach to this subject. We have given special attention to molecular epidemiology, molecular diagnostics, current and new treatments, and drug resistance.

The Sialoglycan Binding Adhesins of Mycoplasma genitalium and Mycoplasma pneumoniae.

Mycoplasma genitalium (Mge) and Mycoplasma pneumoniae (Mpn) are two human pathogens associated with urogenital and respiratory tract infections, respectively. The recent elucidation of the tridimensional structure of their major cytoadhesins by X-ray crystallography and cryo-electron microscopy/tomography, has provided important insights regarding the mechanics of infection and evasion of immune surveillance.

Molecular screening in a longitudinal cohort of young men who have sex with men and young transgender women: associations with focus on the emerging sexually transmitted pathogen Mycoplasma genitalium.

OBJECTIVES: This investigation sought to characterise risk factors associated with acquisition of traditional and emerging agents of sexually transmitted infection (STI) in a cohort of young men who have sex with men and transgender women. METHODS: 917 participants provided urine and rectal swab submissions assessed by transcription-mediated amplification (TMA)-based assays for Chlamydia trachomatis and Neisseria gonorrhoeae and by off-label TMA-based Trichomonas vaginalis and Mycoplasma genitalium testing. A subset provided specimens at 6-month and 12-month follow-up visits. RESULTS: Prevalence of M. genitalium from rectal and urine specimens (21.7% and 8.9%, respectively) exceeded that of C. trachomatis (8.8% and 1.6%) and other STI agents. Black participants yielded higher prevalence of M. genitalium (30.6%) than non-black participants (17.0%; χ²=22.39; p<0.0001). M. genitalium prevalence from rectal specimens was 41.5% in HIV-positive participants vs 16.3% in HIV-negative participants (χ²=57.72; p<0.0001). Participant age, gender identity, condomless insertive anal/vaginal sexual practice and condomless receptive anal sexual practice were not associated with rectal C. trachomatis (p≥0.10), N. gonorrhoeae (p≥0.29), T. vaginalis (p≥0.18) or M. genitalium (p≥0.20) detection. While prevalence of T. vaginalis was calculated at ≤1.0%, baseline rectal and urine screening status was predictive of detection/non-detection at follow-up. A non-reactive M. genitalium baseline rectal or urine screening result was less predictive of non-reactive follow-up versus C. trachomatis, N. gonorrhoeae and T. vaginalis. CONCLUSIONS: Rectal M. genitalium detection is associated with black race and HIV seropositivity. Baseline M. genitalium infection influences subsequent detection of the organism.

Profile of sexually transmitted infections causing urethritis and a related inflammatory reaction in urine among heterosexual males: A flow-cytometry study.

BACKGROUND: Information about the use of flow cytometry in the diagnosis of male urethritis is scarce. The current study aims to evaluate the performance of flow cytometry on first-voided urine in males with infectious urethritis (Chlamydia trachomatis, Neisseria gonorrhoeae, Mycoplasma genitalium and Trichomonas vaginalis). METHODS: Male patients of the Andrology Centre (Tartu University Hospital, Estonia) were recruited during the period March 2015 -January 2018. Cases included 306 patients with infectious urethritis caused by Chlamydia trachomatis, Neisseria gonorrhoeae, Mycoplasma genitalium and/or Trichomonas vaginalis. The control group consisted of 192 patients without uro-genital complaints, negative tests for C. trachomatis, N. gonorrhoeae, M. genitalium and T. vaginalis from first-voided urine and no inflammation in first-voided urine, mid-stream urine and urine after prostate massage. C. trachomatis, N. gonorrhoeae, M. genitalium and T. vaginalis were detected from first-voided urine using polymerase chain reaction (PCR) method. First-voided urine was analysed using urine particle analyzer Sysmex UF-500i. RESULTS: The most prevalent infection was chlamydia (64.1%), followed by Mycoplasma genitalium (20.9%), gonorrhoea (7.8%) and trichomoniasis (1.6%). Gonorrhoea caused the highest flow-cytometric leucocyte/bacteria count, followed by chlamydia and Mycoplasma genitalium. Trichomonas vaginalis showed nearly absent inflammation in first-voided urine. Using an empiric flow-cytometry diagnostic threshold for urethritis in first-voided urine (leucocytes ≥ 15/µl and bacteria ≥ 20/µl) the total calculated sensitivity was over 90%. However, when applying such criteria for deciding whether to perform first-voided urine PCR for C. trachomatis, N. gonorrhoeae, M. genitalium and T. vaginalis or not, we could miss 23 cases with infectious urethritis that makes up 7,5% of all proven cases. CONCLUSIONS: Flow cytometry of first-voided urine can be considered as a rapid and objective screening method in case of suspected male infectious urethritis.

Sequence variation and immunogenicity of the Mycoplasma genitalium MgpB and MgpC adherence proteins during persistent infection of men with non-gonococcal urethritis.

Mycoplasma genitalium is a sexually transmitted bacterial pathogen that infects men and women. Antigenic variation of MgpB and MgpC, the immunodominant adherence proteins of M. genitalium, is thought to contribute to immune evasion and chronic infection. We investigated the evolution of mgpB and mgpC sequences in men with non-gonococcal urethritis persistently infected with M. genitalium, including two men with anti-M. genitalium antibodies at enrollment and two that developed antibodies during follow-up. Each of the four patients was persistently infected with a different strain type and each patient produced antibodies targeting MgpB and MgpC. Amino acid sequence evolution in the variable regions of MgpB and MgpC occurred in all four patients with changes observed in single and multiple variable regions over time. Using the available crystal structure of MgpC of the G37 type strain we found that predicted conformational B cell epitopes localize predominantly to the variable region of MgpC, amino acids that changed during patient infection lie in these epitopes, and variant amino acids are in close proximity to the conserved sialic acid binding pocket. These findings support the hypothesis that sequence variation functions to avoid specific antibodies thereby contributing to persistence in the genital tract.

Serologic markers of Chlamydia trachomatis and other sexually transmitted infections and subsequent ovarian cancer risk: Results from the EPIC cohort.

A substantial proportion of epithelial ovarian cancer (EOC) arises in the fallopian tube and other epithelia of the upper genital tract; these epithelia may incur damage and neoplastic transformation after sexually transmitted infections (STI) and pelvic inflammatory disease. We investigated the hypothesis that past STI infection, particularly Chlamydia trachomatis, is associated with higher EOC risk in a nested case-control study within the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort including 791 cases and 1669 matched controls. Serum antibodies against C. trachomatis, Mycoplasma genitalium, herpes simplex virus type 2 (HSV-2) and human papillomavirus (HPV) 16, 18 and 45 were assessed using multiplex fluorescent bead-based serology. Conditional logistic regression was used to estimate relative risks (RR) and 95% confidence intervals (CI) comparing women with positive vs. negative serology. A total of 40% of the study population was seropositive to at least one STI. Positive serology to C. trachomatis Pgp3 antibodies was not associated with EOC risk overall, but with higher risk of the mucinous histotype (RR = 2.30 [95% CI = 1.22-4.32]). Positive serology for chlamydia heat shock protein 60 (cHSP60-1) was associated with higher risk of EOC overall (1.36 [1.13-1.64]) and with the serous subtype (1.44 [1.12-1.85]). None of the other evaluated STIs were associated with EOC risk overall; however, HSV-2 was associated with higher risk of endometrioid EOC (2.35 [1.24-4.43]). The findings of our study suggest a potential role of C. trachomatis in the carcinogenesis of serous and mucinous EOC, while HSV-2 might promote the development of endometrioid disease.

Mycoplasma genitalium, a stealth female reproductive tract.

Mycoplasma genitalium was first isolated from the urethral swabs of two symptomatic men with urethritis in 1980. It is a sexually transmitted bacterium associated with a number of urogenital conditions in women like cervicitis, endometritis, pelvic inflammatory disease, infertility, and susceptibility to human immunodeficiency virus (HIV). However, M. genitalium may also act like a stealth pathogen at female reproductive tract, giving no symptoms. Its prevalence varies between different groups, with the average being 0.5-10% in the general population and 20-40% in women with sexually transmitted infections. The recommended treatment of this infection is azithromycin as a single 1-g dose. However, in recent years, macrolide resistance has increased which is significantly lowering the cure rate, being less than 50% in some studies. New treatment regimens need to be investigated due to increasing drug resistance. The discussion and suggestion of an algorithm for management of this infection is the highlight of this paper.

Mycoplasma genitalium: A Review.

Mycoplasma genitalium is a fastidious organism of the class Mollicutes, the smallest prokaryote capable of independent replication. First isolated in 1981, much is still unknown regarding its natural history in untreated infection. It is recognized as a sexually transmitted pathogen causing acute and chronic non-gonococcal urethritis (NGU) in men, with a growing body of evidence to suggest it also causes cervicitis and pelvic inflammatory disease in women. Its role in several other clinical syndromes is uncertain. The majority of people infected remain asymptomatic and clear infection without developing disease; asymptomatic screening is therefore not recommended. Prevalence rates are higher in patients attending sexual health clinics and in men with NGU. Limited availability of diagnostics has encouraged syndromic management, resulting in widespread antimicrobial resistance and given that few antimicrobial classes have activity against M. genitalium, there is significant concern regarding the emergence of untreatable strains. There is a need for wider availability of testing, which should include detection of macrolide resistance mediating mutations. Expertise in interpretation of microbiological results with clinical correlation ensures targeted treatment avoiding unnecessary antibiotic exposure. Public health surveillance nationally and internationally is vital in monitoring and responding to changing epidemiology trends. In this review, we summarize current knowledge of M. genitalium, including epidemiology, clinical and microbiological data, and discuss treatment challenges in the era of rising multidrug resistance.

High rates of treatment failure for Mycoplasma genitalium among men and women attending a sexual health clinic.

BACKGROUND: Mycoplasma genitalium (Mgen) causes non-gonococcal urethritis (NGU) and is believed to cause pelvic inflammatory disease (PID). High rates of macrolide resistance are well documented globally for Mgen. In Brighton, patients with NGU and PID are tested for Mgen and test of cure (TOC) offered post-treatment. METHODS: Demographic, clinical and treatment history data were collected over a 12-month period for all Mgen-positive patients in a Brighton-based genitourinary clinic. RESULTS: There were 114 patients with Mgen. 18% (61/339) of men with NGU and 9% (15/160) of women with PID had Mgen. 62/114 (54%) returned for first test TOC 4 weeks after treatment. 27/62 (44%) had a positive TOC; 25/27 (92.6%) had received azithromycin first line (500 mg stat then 250 mg OD for 4 days), 1/27 (3.7%) had received moxifloxacin first line (400 mg OD for 14 days) and 1/27 (3.7%) had received doxycycline first line (100 mg BD for 7 days). 20/27 (74%) returned for a second TOC 4 weeks later. 5/20 (25%) patients were positive on second TOC; 3/5 (60%) had received azithromycin second line and 2/5 (40%) had received moxifloxacin second line. Patients were more likely to have a positive TOC if they were at risk of reinfection (9/27 positive TOC vs 3/35 negative TOC; p=0.02). Patients given moxifloxacin were more likely to have a negative TOC (1/27 positive TOC vs 9/35 negative TOC; p=0.03) than those who received other antibiotic regimens. CONCLUSIONS: Treatment failure rates for Mgen following azithromycin use are substantial, raising concerns regarding resistance. However, reinfection risk may contribute, suggesting a requirement for improved public awareness and clinician knowledge.

Sexually transmitted infections and risk of epithelial ovarian cancer: results from the Nurses' Health Studies.

BACKGROUND: Sexually transmitted infections (STIs) are associated with pelvic inflammatory disease and tubal pathologies. Given the tubal origin of a proportion of ovarian cancers, STIs may be relevant in their aetiology. METHODS: Antibodies indicating past infection with Chlamydia trachomatis, Mycoplasma genitalium, herpes simplex virus type 2, and against human papillomavirus oncogenes (L1 and E6+E7 oncoproteins of types 16, 18, 45) were measured in prediagnosis plasma samples in a nested case-control study in the Nurses' Health Studies (n = 337 cases 1:1 matched to controls). Logistic regression was used to estimate multivariable-adjusted relative risks (RRs) and 95% confidence intervals [CIs] comparing women seropositive vs. seronegative among all cases (invasive and borderline), invasive (n = 257), and invasive serous ovarian cancers; n = 170), and borderline ovarian tumours (n = 80). RESULTS: C. trachomatis seropositivity was associated with higher risk of ovarian cancer overall (RR = 2.07 [1.25-3.43]); results were similar for invasive, invasive serous, and borderline tumours. We observed no associations for the other STIs. Relative to women seronegative to all infections, strongest associations were observed for seropositivity to C. trachomatis plus another STI (2.74 [1.20-6.27]; C. trachomatis alone, 1.88 [1.03-3.42]; all cases); however, the RRs were not significantly different. CONCLUSIONS: C. trachomatis infection may increase ovarian cancer risk; additional studies are required.

Investigation on silent bacterial infections in specimens from pregnant women affected by spontaneous miscarriage.

Miscarriage is one of the main complications occurring in pregnancy. The association between adverse pregnancy outcomes and silent bacterial infections has been poorly investigated. Ureaplasma parvum and urealiticum, Mycoplasma genitalium and hominis and Chlamydia trachomatis DNA sequences have been investigated by polymerase chain reaction (PCR) methods in chorionic villi tissues and peripheral blood mononuclear cells (PBMCs) from females with spontaneous abortion (SA, n = 100) and females who underwent voluntary interruption of pregnancy (VI, n = 100). U. parvum DNA was detected in 14% and 15% of SA and VI, respectively, with a mean of bacterial DNA load of 1.3 × 10-1 copy/cell in SA and 2.8 × 10 -3 copy/cell in VI; U. urealiticum DNA was detected in 3% and 2% of SA and VI specimens, respectively, with a mean DNA load of 3.3 × 10-3 copy/cell in SA and 1.6 × 10-3 copy/cell in VI; M. hominis DNA was detected in 5% of SA specimens with a DNA load of 1.3 × 10-4 copy/cell and in 6% of VI specimens with a DNA load of 1.4 × 10-4 copy/cell; C. trachomatis DNA was detected in 3% of SA specimens with a DNA load of 1.5 × 10-4 copy/cell and in 4% of VI specimens with a mean DNA load of 1.4 × 10-4 copy/cell. In PBMCs from the SA and VI groups, Ureaplasma spp, Mycoplasma spp and C. trachomatis DNAs were detected with a prevalence of 1%-3%. Bacteria were investigated, for the first time, by quantitative real-time PCR (qPCR) in chorionic villi tissues and PBMCs from women affected by SA and VI. These data may help to understand the role and our knowledge of the silent infections in SA.

The two-sided role of the vaginal microbiome in Chlamydia trachomatis and Mycoplasma genitalium pathogenesis.

Sexually transmitted infections (STI) can have major consequences for the reproductive health of women. Mycoplasma genitalium is a STI that is not as well studied but causes pelvic inflammatory disease (PID) among other complications. Another well-known STI is Chlamydia trachomatis, notorious for its capability to cause infertility. Both C. trachomatis and M. genitalium share some of the same clinical aspects. Parts of the pathogenesis of C. trachomatis and M. genitalium infections are unclear but potential factors are the microbiome and other STIs. The healthy vaginal microbiome is dominated by Lactobacillus spp; these bacteria protect the host against invading bacteria like C. trachomatis and M. genitalium by producing antibacterial compounds and providing a mechanical barrier. A dysbiosis of the vaginal microbiome is characterized by a non-Lactobacillus spp. dominated microbiome, also known as bacterial vaginosis (BV). BV and BV associated bacteria play a role in the pathogenesis of STIs such as C. trachomatis and M. genitalium. The different species of BV associated bacteria have distinct characteristics that could play a role in C. trachomatis and M. genitalium infections. Host factors should also be considered when analysing the interaction of C. trachomatis and M. genitalium and the microbiome. One important factor is the hormonal homeostasis. Oral hormonal contraception influences the vaginal milieu and could influence the infection process of STIs. Overall, this review attempts to give an overview of the pathogenesisof C. trachomatis and M. genitalium infections and the relationship between M. genitalium, C. trachomatis, and the vaginal microbiome.

Mycoplasma genitalium infections in Cuba: surveillance of urogenital syndromes, 2014-2015.

Mycoplasma genitalium is an emerging sexually transmitted pathogen implicated in urethritis in men and several inflammatory reproductive tract syndromes in women. The prevalence of M. genitalium infections in Cuban patients with urogenital syndromes is unknown. The aim of this study was to analyse the prevalence of M. genitalium infection in sexually-active Cuban men and women with urogenital syndromes as a part of aetiological surveillance of urogenital syndromes in Cuba. Samples from men and women with urogenital syndromes submitted to the Mycoplasma Reference Laboratory for mycoplasma diagnosis from 1 January 2014 to 1 June 2015 were analysed by polymerase chain reaction (PCR) for detection of M. genitalium. A total of 971 samples were received and processed. Of the patients tested, 5.7% (47/824) of women and 27.9% (41/147) of men were positive for M. genitalium. This paper presents the largest study of M. genitalium infections among Cuban patients with urogenital syndromes and is Cuba's first M. genitalium survey. We suggest that M. genitalium should be considered in the Cuban sexually transmitted infection management protocols as an important pathogen, particularly in men.

Cyclophilin A is the potential receptor of the Mycoplasma genitalium adhesion protein.

The Mycoplasma genitalium adhesion protein (MgPa), the most important outer membrane protein of M. genitalium, plays a vital role in the adhesion to and invasion of host cells by M. genitalium. Identification of MgPa receptors will help elucidate the pathogenic mechanism of M. genitalium. However, the receptor protein of MgPa has not been reported to date. In this study, an MgPa-binding protein with a molecular weight of approximately 17 kDa was screened from SV-HUC-1 cell membrane proteins by a modified virus overlay protein binding assay (VOPBA). Liquid chromatography-mass spectrometry (LC-MS) was used to analyze the protein components of the 17-kDa protein. The results demonstrated that the MgPa-binding protein was most likely Cyclophilin A (CyPA). The binding activity and distribution of CyPA in SV-HUC-1 cells were detected using indirect ELISA, western blotting, far-western blotting and indirect immunofluorescence. We found that recombinant MgPa (rMgPa) could bind with CyPA from SV-HUC-1 cell membrane proteins and to recombinant CyPA, which indicated that CyPA was predominant component of the 17-kDa protein band and can interact with rMgPa. In addition, an indirect immunofluorescence assay showed that CyPA was partially distributed on the membrane surfaces of SV-HUC-1 cells and could partially inhibit the adhesion of rMgPa and M. genitalium to SV-HUC-1 cells. Co-localization assays further indicated that rMgPa and M. genitalium can interact with CyPA. These results suggested that the CyPA located on SV-HUC-1 cell membranes may be the potential receptor of MgPa, which could provide an experimental basis for elucidating the function of MgPa and the possible pathogenic mechanism of M. genitalium.

Highlighting the clinical need for diagnosing Mycoplasma genitalium infection.

Despite Mycoplasma genitalium (MG) being increasingly recognised as a genital pathogen in men and women, awareness and utility of commercially available MG-testing has been low. The opinion of UK sexual health clinicians and allied professionals was sought on how MG-testing should be used. Thirty-two consensus statements were developed by an expert group and circulated to clinicians and laboratory staff, who were asked to evaluate their level of agreement with each statement; 75% agreement was set as the threshold for defining consensus for each statement. A modified Delphi approach was used and high levels of agreement obviated the need to test the original statement set further. Of 201 individuals who received questionnaires, 60 responded, most (48) being sexual health consultants, more than 10% of the total in the UK. Twenty-seven (84.4%) of the statements exceeded the 75% threshold. Respondents strongly supported MG-testing of patients with urethritis, pelvic inflammatory disease or unexplained persistent vaginal discharge, or post-coital bleeding. Fewer favoured testing patients with proctitis and support was divided for routinely testing Chlamydia-positive patients. Testing of current sexual contacts of MG-positive patients was supported, as was a test of cure for MG-positive patients, although agreement fell below the 75% threshold. Respondents agreed that all consultant- or specialist-led services should have access to testing for MG (98.3%). There was strong agreement for having MG-testing available for specific patient groups, which may reflect concern over antibiotic resistance and the desire to comply with clinical guidelines that recommend MG-testing in sexual health clinic settings.