Role of Mycoplasma genitalium and Ureaplasma urealyticum in acute and chronic nongonococcal urethritis

Comparison of analytical sensitivity of DNA-based and RNA-based nucleic acid amplification tests for reproductive tract infection pathogens: implications for clinical applications

Currently, DNA-based nucleic acid amplification tests (NAATs) and RNA-based NAATs are employed to detect reproductive tract infection (RTI) pathogens including Chlamydia trachomatis (CT), Neisseria gonorrhoeae (NG), and Ureaplasma urealyticum (UU). Although evaluations of DNA-based NAATs have already existed, the comparison of the two methods is scarce. Thus, we compared the limits of detection (LODs) of DNA-based and RNA-based NAATs on the same experimental conditions. Inactivated culture supernatants of CT, NG, and UU with determined pathogen DNA and RNA load were used to evaluate LODs of seven DNA kits and one RNA kit. The LODs of the seven DNA kits for CT, NG, and UU ranged between 38-1,480, 94-20,011, and 132-2,011 copies/mL, respectively. As for RNA kits, they could detect samples at RNA concentrations of 3,116, 2,509, and 2,896 copies/mL, respectively. The RNA concentrations of CT, NG, and UU were 40, 885, and 42 times that of corresponding pathogen DNA concentrations in the employed supernatants, so RNA kits could detect pathogen DNA concentrations as low as 78 copies/mL, 3 copies/mL, and 69 copies/mL, respectively, but the level of pathogen load that the RNA tests could detect was primarily dependent on the infectious phase and transcriptional level of RNA. Thus, a schematic of bacterial dynamics during the period of reproductive tract infections was provided, which suggests that in terms of the analytical sensitivity of pathogen detection, RNA tests are more suitable for detecting active infection and recovery phase, while DNA tests are more suitable for detection in the early stage of infection. IMPORTANCE Reproductive tract infections have considerable effects on the health of humans. CT, NG , and UU are common pathogens. Although evaluation of DNA-based tests has already existed, the comparison between DNA-based and RNA-based tests is rare. Therefore, this study compared the limits of detection of the two tests on the same experimental conditions. Results suggested that most DNA-based NAATs could detect CT, NG, and UU at DNA concentrations lower than 1,000 copies/mL, while RNA-based NAATs could detect bacteria at RNA concentrations around 3,000 copies/mL. Considering the copy number of RNA per bacterium is dynamic through the growth cycle, further comparison is combined with a schematic of bacterial dynamics. Results suggested that in terms of the analytical sensitivity of pathogen detection, RNA tests are more suitable for detecting active infection and recovery phase, while DNA tests are more suitable for detection in the early stage of infection.

Updates on Sexually Transmitted Urethro-cystitis

Purpose of Review

We performed recent literature review with the aim to address the updates in diagnosis and management of sexually transmitted urethro-cystitis.

Recent Findings

There are multiple, recently published studies that collectively lead to an organized stepwise plan for diagnosis and management of sexually transmitted urethro-cystitis.

Summary

Sexually transmitted urethro-cystitis is a common health condition that can be managed efficiently if the appropriate steps are taken in diagnosis and management.

Analysis of Ureaplasma urealyticum, Chlamydia trachomatis, Mycoplasma genitalium and Neisseria gonorrhoeae infections among obstetrics and gynecological outpatients in southwest China: a retrospective study

Background

The aim of this study was to analyze the present situation of Ureaplasma urealyticum (UU), Chlamydia trachomatis (CT), Mycoplasma genitalium (MG) and Neisseria gonorrhoeae (NG) infections among obstetrics and gynecological outpatients in southwest China.

Methods

A total of 3225 urogenital swabs were included in this study. All swabs were tested by RNA-based simultaneous amplification and testing (SAT) methods. Routine analysis of leucorrhea smear and drug susceptibility were performed in UU positive patients.

Results

Of these 3225 outpatients, the positive rate was 27.07% for UU, 4.99% for CT, 3.10% for MG, and 0.09% for NG. UU, CT, and MG infections were more common in women of reproductive age (aged 25–34 years), while NG infection was more prominent in women aged 30–34 years and over 40 years. Overall, the infection rate of UU was significantly higher than that of the other three infections, and UU also played a major role even in the mixed infections. 65.07% of the UU positive patients had negative results on routine leucorrhea smear analysis, and the remaining patients may have bacterial vaginitis (15.79%), fungal vaginitis (11.48%), trichomonas vaginitis (0.96%) or other vaginal inflammation (6.70%). We have observed that maternal UU infection can lead to low birth weight, neonatal pneumonia, and premature delivery. The results of the drug susceptibility test of UU showed a higher sensitivity to pristinamycin, doxycycline, tetracycline, clarithromycin, and josamycin (100%, 97.0%, 96.4%, 95.9%, and 95.3%, respectively), and lower sensitivity to ciprofloxacin and ofloxacin (2.4% and 4.7% respectively).

Conclusions

This study could contribute to a better understanding of the current epidemiological features of UU, CT, MG, and NG among obstetrics and gynecological outpatients in southwest China, and thus facilitate to development of the more effective intervention, prevention, and treatment of reproductive tract infection.

Comparative Analysis of the Incidence of Selected Sexually Transmitted Bacterial Infections in Poland in 2010-2015: A Retrospective Cohort Study

Sexually transmitted infections are common infectious diseases. The main aim of this study was to perform a comparative analysis of the incidence of bacterial sexually transmitted infections in 2010-2015 in Poland, taking into account the administrative division of the country into provinces. This was a retrospective study. The analysed data came from the Centre for Health Information Systems of the Ministry of Health and constituted information being the epidemiological surveillance system in Poland. The analysis included data on the incidence of primary and secondary syphilis, gonorrhoea and non-gonococcal urethritis and genital infections. The overall incidence rates were disproportionately lower than European rates and those presented in studies from other countries. Young people, between 20 and 29 years of age, were the key groups at the highest risk of infection. The incidence rate of primary and secondary syphilis was lower in Poland than in Europe or America, but some regions, such as Mazovia and Lodz provinces, were found to have a higher incidence rate than other European rates. The reported incidence of gonorrhoea in Poland was also significantly lower compared with other countries, with a significantly higher number of infections in males than in females, and this was also one of the highest rates in EU countries. During the study period, the number of non-gonococcal genital infections systematically decreased, while in other countries of the European region, the incidence was among the highest of all sexually transmitted infections.

Mycoplasma genitalium: A new superbug

Mycoplasma genitalium (MG) is an emerging sexually transmitted pathogen. It is an important cause of nongonococcal urethritis in men and is associated with cervicitis and pelvic inflammatory disease in women, putting them at risk of infertility. Multiple factors that aid pathogenesis of MG include its ability of adhesion, gliding motility, and intracellular invasion by means of the tip organelle. Through intracellular localization and antigenic variation, MG could result in treatment-resistant chronic infection. There are limited data on the prevalence of MG in Indian patients with urogenital syndromes. Recently, a high prevalence of extra genital infection with MG has been reported. Molecular assays are the major diagnostic techniques of MG infection. Antimicrobial agents such as macrolides, along with fluoroquinolones, are the treatment of choice for MG infections. The issue of drug resistance to azithromycin and fluoroquinolones in MG is rising globally. As molecular tests are becoming available for MG, both for the diagnosis and the detection of antimicrobial resistance, any patient with MG infection should then be tested for antimicrobial resistance. Consideration of MG as a cause of sexually transmitted disease in the Indian population is crucial in diagnostic algorithms and treatment strategies. The purpose of this review is to understand the prevalence of MG in different clinical scenarios, molecular mechanisms of pathogenesis, current status of antimicrobial resistance, and its impact on MG treatment.

Evaluation of Clinical, Gram Stain, and Microbiological Cure Outcomes in Men Receiving Azithromycin for Acute Nongonococcal Urethritis: Discordant Cures Are Associated With Mycoplasma genitalium Infection

BACKGROUND

In men with nongonococcal urethritis (NGU), clinicians and patients rely on clinical cure to guide the need for additional testing/treatment and when to resume sex, respectively; however, discordant clinical and microbiological cure outcomes do occur. How accurately clinical cure reflects microbiological cure in specific sexually transmitted infections (STIs) is unclear.

METHODS

Men with NGU were tested for Neisseria gonorrhoeae, Chlamydia trachomatis (CT), Mycoplasma genitalium (MG), Trichomonas vaginalis, urethrotropic Neisseria meningitidis ST-11 clade strains, and Ureaplasma urealyticum (UU). Men received azithromycin 1 g and returned for a 1-month test-of-cure visit. In MG infections, we evaluated for the presence of macrolide resistance-mediating mutations (MRMs) and investigated alternate hypotheses for microbiological treatment failure using in situ shotgun metagenomic sequencing, phylogenetic analysis, multilocus sequence typing analyses, and quantitative PCR.

RESULTS

Of 280 men with NGU, 121 were included in this analysis. In the monoinfection group, 52 had CT, 16 had MG, 7 had UU, 10 had mixed infection, and 36 men had idiopathic NGU. Clinical cure rates were 85% for CT, 100% for UU, 50% for MG, and 67% for idiopathic NGU. Clinical cure accurately predicted microbiological cure for all STIs, except MG. Discordant results were significantly associated with MG-NGU and predominantly reflected microbiological failure in men with clinical cure. Mycoplasma genitalium MRMs, but not MG load or strain, were strongly associated with microbiological failure.

CONCLUSIONS

In azithromycin-treated NGU, clinical cure predicts microbiological cure for all STIs, except MG. Nongonococcal urethritis management should include MG testing and confirmation of microbiological cure in azithromycin-treated MG-NGU when MRM testing is unavailable.

The Zonulin-transgenic mouse displays behavioral alterations ameliorated via depletion of the gut microbiota

The gut-brain axis hypothesis suggests that interactions in the intestinal milieu are critically involved in regulating brain function. Several studies point to a gut-microbiota-brain connection linking an impaired intestinal barrier and altered gut microbiota composition to neurological disorders involving neuroinflammation. Increased gut permeability allows luminal antigens to cross the gut epithelium, and via the blood stream and an impaired blood-brain barrier (BBB) enters the brain impacting its function. Pre-haptoglobin 2 (pHP2), the precursor protein to mature HP2, is the first characterized member of the zonulin family of structurally related proteins. pHP 2 has been identified in humans as the thus far only endogenous regulator of epithelial and endothelial tight junctions (TJs). We have leveraged the Zonulin-transgenic mouse (Ztm) that expresses a murine pHP2 (zonulin) to determine the role of increased gut permeability and its synergy with a dysbiotic intestinal microbiota on brain function and behavior. Here we show that Ztm mice display sex-dependent behavioral abnormalities accompanied by altered gene expression of BBB TJs and increased expression of brain inflammatory genes. Antibiotic depletion of the gut microbiota in Ztm mice downregulated brain inflammatory markers ameliorating some anxiety-like behavior. Overall, we show that zonulin-dependent alterations in gut permeability and dysbiosis of the gut microbiota are associated with an altered BBB integrity, neuroinflammation, and behavioral changes that are partially ameliorated by microbiota depletion. Our results suggest the Ztm model as a tool for the study of the cross-talk between the microbiome/gut and the brain in the context of neurobehavioral/neuroinflammatory disorders.

A Review of Ureaplasma diversum: A Representative of the Mollicute Class Associated With Reproductive and Respiratory Disorders in Cattle

The Mollicutes class encompasses wall-less microbes with a reduced genome. They may infect plants, insects, humans, and animals including those on farms and in livestock. Ureaplasma diversum is a mollicute associated with decreased reproduction mainly in the conception rate in cattle, as well as weight loss and decreased quality in milk production. Therefore, U. diversum infection contributes to important economic losses, mainly in large cattle-producing countries such as the United States, China, Brazil, and India. The characteristics of Mollicutes, virulence, and pathogenic variations make it difficult to control their infections. Genomic analysis, prevalence studies, and immunomodulation assays help better understand the pathogenesis of bovine ureaplasma. Here we present the main features of transmission, virulence, immune response, and pathogenesis of U. diversum in bovines.

Genomic and Resistance Epidemiology of Gram-Negative Bacteria in Africa: a Systematic Review and Phylogenomic Analyses from a One Health Perspective

Antibiotic resistance (AR) is one of the major public health threats and challenges to effective containment and treatment of infectious bacterial diseases worldwide. Here, we used different methods to map out the geographical hot spots, sources, and evolutionary epidemiology of AR. Escherichia coli, Klebsiella pneumoniae, Salmonella enterica, Acinetobacter baumannii, Pseudomonas aeruginosa, Enterobacter spp., Neisseria meningitis/gonorrhoeae, Vibrio cholerae, Campylobacter jejuni, etc., were common pathogens shuttling AR genes in Africa. Transmission of the same clones/strains across countries and between animals, humans, plants, and the environment was observed. We recommend Enterobacter spp. or K. pneumoniae as better sentinel species for AR surveillance.

Antibiotic resistance (AR) remains a major threat to public and animal health globally. However, AR ramifications in developing countries are worsened by limited molecular diagnostics, expensive therapeutics, inadequate numbers of skilled clinicians and scientists, and unsanitary environments. The epidemiology of Gram-negative bacteria, their AR genes, and geographical distribution in Africa are described here. Data were extracted and analyzed from English-language articles published between 2015 and December 2019. The genomes and AR genes of the various species, obtained from the Pathosystems Resource Integration Center (PATRIC) and NCBI were analyzed phylogenetically using Randomized Axelerated Maximum Likelihood (RAxML) and annotated with Figtree. The geographic location of resistant clones/clades was mapped manually. Thirty species from 31 countries and 24 genera from 41 countries were analyzed from 146 articles and 3,028 genomes, respectively. Genes mediating resistance to β-lactams (including bla_TEM-1, bla_CTX-M, bla_NDM, bla_IMP, bla_VIM, and bla_OXA-48/181), fluoroquinolones (oqxAB, qnrA/B/D/S, gyrA/B, and parCE mutations, etc.), aminoglycosides (including armA and rmtC/F), sulfonamides (sul1/2/3), trimethoprim (dfrA), tetracycline [tet(A/B/C/D/G/O/M/39)], colistin (mcr-1), phenicols (catA/B, cmlA), and fosfomycin (fosA) were mostly found in Enterobacter spp. and Klebsiella pneumoniae, and also in Serratia marcescens, Escherichia coli, Salmonella enterica, Pseudomonas, Acinetobacter baumannii, etc., on mostly IncF-type, IncX_3/4, ColRNAI, and IncR plasmids, within IntI1 gene cassettes, insertion sequences, and transposons. Clonal and multiclonal outbreaks and dissemination of resistance genes across species and countries and between humans, animals, plants, and the environment were observed; Escherichia coli ST103, K. pneumoniae ST101, S. enterica ST1/2, and Vibrio cholerae ST69/515 were common strains. Most pathogens were of human origin, and zoonotic transmissions were relatively limited.

IMPORTANCE Antibiotic resistance (AR) is one of the major public health threats and challenges to effective containment and treatment of infectious bacterial diseases worldwide. Here, we used different methods to map out the geographical hot spots, sources, and evolutionary epidemiology of AR. Escherichia coli, Klebsiella pneumoniae, Salmonella enterica, Acinetobacter baumannii, Pseudomonas aeruginosa, Enterobacter spp., Neisseria meningitis/gonorrhoeae, Vibrio cholerae, Campylobacter jejuni, etc., were common pathogens shuttling AR genes in Africa. Transmission of the same clones/strains across countries and between animals, humans, plants, and the environment was observed. We recommend Enterobacter spp. or K. pneumoniae as better sentinel species for AR surveillance.

The Role of Ureaplasma spp. in the Development of Nongonococcal Urethritis and Infertility among Men

Ureaplasma spp. are a genus of bacteria for which two human-associated species exist: Ureaplasma urealyticum and Ureaplasma parvum Their definition as a pathogen in the context of nongonococcal urethritis (NGU) and infertility among males remains highly controversial, largely due to historically high rates of isolation of these bacteria from the urethra of seemingly healthy men. This review summarizes the emerging evidence suggesting a true pathogenic role of these bacteria under specific conditions, which we term risk factors. We examine the historical, clinical, and experimental studies which support a causal role for Ureaplasma spp. in the development of NGU as well as some of the proposed mechanisms behind the association of Ureaplasma spp. and the development of infertility. Finally, we discuss the potential for developing a case-by-case risk-based approach toward the management of men who present with seemingly idiopathic NGU but who are positive for Ureaplasma spp.

Aetiology and prevalence of mixed-infections and mono-infections in non-gonococcal urethritis in men: a case-control study

OBJECTIVES

Chlamydia trachomatis (CT) and Mycoplasma genitalium (MG) cause the majority of non-gonococcal urethritis (NGU). The role of Ureaplasma urealyticum (UU) in NGU is unclear. Prior case-control studies that examined the association of UU and NGU may have been confounded by mixed infections and less stringent criteria for controls. The objective of this case-control study was to determine the prevalence and aetiology of mixed infections in men and assess if UU monoinfection is associated with NGU.

METHODS

We identified 155 men with NGU and 103 controls. Behavioural and clinical information was obtained and men were tested for Neisseria gonorrhoeae and CT, MG, UU and Trichomonas vaginalis (TV). Men who were five-pathogen negative were classified as idiopathic urethritis (IU).

RESULTS

Twelve per cent of NGU cases in which a pathogen was identified had mixed infections, mostly UU coinfections with MG or CT; 27% had IU. In monoinfected NGU cases, 34% had CT, 17% had MG, 11% had UU and 2% had TV. In controls, pathogens were rarely identified, except for UU, which was present in 20%. Comparing cases and controls, NGU was associated with CT and MG monoinfections and mixed infections. UU monoinfection was not associated with NGU and was almost twice as prevalent in controls. Men in both the case and control groups who were younger and who reported no prior NGU diagnosis were more likely to have UU (OR 0.97 per year of age, 95% CI 0.94 to 0.998 and OR 6.3, 95% CI 1.4 to 28.5, respectively).

CONCLUSIONS

Mixed infections are common in men with NGU and most of these are UU coinfections with other pathogens that are well-established causes of NGU. UU monoinfections are not associated with NGU and are common in younger men and men who have never previously had NGU. Almost half of NGU cases are idiopathic.

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.

Health-related quality of life and psychosocial impacts of a diagnosis of non-specific genital infection in symptomatic heterosexual men attending UK sexual health clinics: a feasibility study

INTRODUCTION

Non-specific genital infection (NSGI; non-Chlamydia trachomatis, non-Neisseria gonorrhoeae-associated urethritis) is a common diagnosis in symptomatic heterosexual men attending UK sexual health clinics (SHCs). but little is known about the psychosocial impact of this diagnosis.

METHODS

We conducted an observational study among symptomatic heterosexual men attending SHCs to evaluate the psychosocial impact of an NSGI diagnosis compared with a diagnosis of Chlamydia trachomatis (CT), Neisseria gonorrhoeae or no abnormalities detected focusing on the feasibility of our study methodology. Participants completed a computer-assisted self-interviewing (CASI) including two validated measures of psychosocial impact: the EQ-5D-5L health-related quality of life and Rosenberg Self-Esteem Scale, before diagnostic testing and 2 weeks after receiving test results (follow-up 1 (FU-1)) and a qualitative interview. We compared scores between diagnostic groups using paired t-tests, qualitative data were analysed thematically and feasibility was assessed by process analysis.

RESULTS

60 men completed the baseline CASI (75% response rate). 46 (76.6%) were eligible for follow-up; 11/46 (23.9%) completed the follow-up CASI, and 3/11 (27.3%) completed the qualitative interview. 81.7% of all participants left CASI feedback at baseline: 73.5% reported the questionnaire as 'fine' or 'very good'. Qualitative interview participants reported the study was acceptable. Compared with baseline, among patients completing FU-1, only patients with a diagnosis of NSGI (p<0.05) or CT (p<0.05) showed increased EQ-5D-5L Index, whereas patients with a diagnosis of NSGI (p=0.05) showed decreased mean Rosenberg Self-Esteem Scale score.

CONCLUSIONS

Although most participants indicated study acceptability at baseline, and we employed measures to increase retention (CASI questionnaires, reminder messages and a focus on men's health), we experienced high loss to follow-up. We found that heterosexual men attending SHCs with symptoms of urethritis experience both positive and negative psychosocial impacts following their clinic attendance, which warrants further investigation.

Chlamydia trachomatis, Ureaplasma urealyticum and Neisseria gonorrhoeae among Chinese women with urinary tract infections in Shanghai: A community-based cross-sectional study

AIM

This study explored chlamydia trachomatis (CT), ureaplasma urealyticum (UU) and/or neisseria gonorrhoeae (NG) in 5893 women with urinary tract infections (UTIs) in Shanghai.

METHODS

From January 2009 to December 2014, 5893 women with UTIs in Shanghai were selected to undergo CT, UU and NG detection. Baseline characteristics including age, education level, occupation, reproductive history, sexual behavior and contraceptive method were obtained for epidemiological analysis.

RESULTS

The total CT, UU and/or NG infection rate in the urine samples of 5893 patients was 50.69% (2987/5893), while the infection rate in vaginal secretion samples was 56.22% (3313/5893). The two detection methods were consistent. Patients aged 21-30, service personnel and unemployed persons had the highest rates of CT, UU and/or NG infection, while patients with higher education levels exhibited lower rates. As the number of previous pregnancies, natural births, abortions, sexual partners and the frequency of sexual intercourse increased, the rates of CT, UU and/or NG infection were elevated. Sexual intercourse during the menstruation period, a lack of cleaning before sexual intercourse and the use of intrauterine devices could all lead to an increased rate of CT, UU and/or NG infection.

CONCLUSIONS

These data revealed that the rate of CT, UU and/or NG infection may be associated with age, education level, occupation, reproductive history, sexual behavior and type of contraceptive method in female patients with UTI in Shanghai.

[Non-viral sexually transmitted infections - Epidemiology, clinical manifestations, diagnostics and therapy : Part 2: Chlamydia and mycoplasma]

Chlamydia trachomatis is the most common pathogen of sexually transmitted bacterial infections worldwide. Every year in Germany approximately 300,000 new infections are to be expected. Chlamydia infections occur nearly exclusively in the postpubertal period. The peak age group is 15-25 years. The infection usually runs an asymptomatic course and the diagnosis is made by nucleic acid amplification techniques (NAAT) often after chlamydial screening or if complications occur. For treatment of chlamydial infections oral doxycycline 100 mg twice daily over 7 days is initially used or alternatively oral azithromycin 1.5 g as a single dose is recommended. The sexual partner should also be investigated and treated. Genital Mycoplasma infections are caused by Ureaplasma urealyticum (pathogen of urethritis and vaginitis), Ureaplasma parvum (mostly saprophytic and rarely a cause of urethritis) and Mycoplasma hominis (facultative pathogenic). Mycoplasma genitalium represents a relatively new sexually transmitted Mycoplasma species. Doxycycline is effective in Ureaplasma infections or alternatively clarithromycin and azithromycin. Doxycycline can be ineffective in Mycoplasma hominis infections and an alternative is clindamycin. Non-gonococcal and non-chlamydial urethritis due to Mycoplasma genitalium can now be diagnosed by molecular biological techniques using PCR and should be treated by azithromycin.

Experimental Infection of Pig-Tailed Macaques (Macaca nemestrina) with Mycoplasma genitalium

Mycoplasma genitalium is an underappreciated cause of human reproductive tract disease, characterized by persistent, often asymptomatic, infection. Building on our previous experiments using a single female pig-tailed macaque as a model for M. genitalium infection (G. E. Wood, S. L. Iverson-Cabral, D. L. Patton, P. K. Cummings, Y. T. Cosgrove Sweeney, and P. A. Totten, Infect Immun 81:2938-2951, 2013, https://doi.org/10.1128/IAI.01322-12), we cervically inoculated eight additional animals, two of which were simultaneously inoculated in salpingeal tissue autotransplanted into abdominal pockets. Viable M. genitalium persisted in the lower genital tract for 8 weeks in three animals, 4 weeks in two, and 1 week in one; two primates resisted infection. In both animals inoculated in salpingeal pockets, viable M. genitalium was recovered for 2 weeks. Recovery of viable M. genitalium from lower genital tract specimens was improved by diluting the specimen in broth and by Vero cell coculture. Ascension to upper reproductive tract tissues was not detected, even among three persistently infected animals. M. genitalium-specific serum antibodies targeting the immunodominant MgpB and MgpC proteins appeared within 1 week in three animals inoculated both cervically and in salpingeal pockets and in one of three persistently infected animals inoculated only in the cervix. M. genitalium-specific IgG, but not IgA, was detected in cervical secretions of serum antibody-positive animals, predominantly against MgpB and MgpC, but was insufficient to clear M. genitalium lower tract infection. Our findings further support female pig-tailed macaques as a model of M. genitalium infection, persistence, and immune evasion.

A Case of Rectal Ureaplasma Infection and Implications for Testing in Young Men Who Have Sex with Men: The P18 Cohort Study

Ureaplasma is a significant cause of nongonococcal urethritis. This is a case of rectal Ureaplasma found on culture in a young man who has sex with men not previously reported in the literature. Nucleic acid amplification tests are now standard of care for sexually transmitted infection testing, but they do not test for Ureaplasma and, therefore, may be missing important infections. Ureaplasma could have important implications in urethritis and rectal HIV transmission among men who have sex with men engaging in condomless anal intercourse. Further study of Ureaplasma's role as a rectal pathogen may be warranted.

Advances in the Understanding and Treatment of Male Urethritis

Neisseria gonorrhoeae and Chlamydia trachomatis are well-documented urethral pathogens, and the literature supporting Mycoplasma genitalium as an etiology of urethritis is growing. Trichomonas vaginalis and viral pathogens (herpes simplex virus types 1 and 2 and adenovirus) can cause urethritis, particularly in specific subpopulations. New data are emerging regarding the potential role of bacterial vaginosis-associated bacteria in urethritis, although results are inconsistent regarding the pathogenic role of Ureaplasma urealyticum in men. Mycoplasma hominis and Ureaplasma parvum do not appear to be pathogens. Men with suspected urethritis should undergo evaluation to confirm urethral inflammation and etiologic cause. Although nucleic acid amplification testing would detect N. gonorrhoeae and C. trachomatis (or T. vaginalis if utilized), there is no US Food and Drug Administration-approved clinical test for M. genitalium available in the United States at this time. The varied etiologies of urethritis and lack of diagnostic options for some organisms present treatment challenges in the clinical setting.

Efficacy of Antimicrobial Therapy for Mycoplasma genitalium Infections

Mycoplasma genitalium has been causally linked with nongonococcal urethritis in men and cervicitis, pelvic inflammatory disease, preterm birth, spontaneous abortion, and infertility in women, yet treatment has proven challenging. To inform treatment recommendations, we reviewed English-language studies describing antimicrobial susceptibility, resistance-associated mutations, and clinical efficacy of antibiotic therapy, identified via a systematic search of PubMed supplemented by expert referral. Minimum inhibitory concentrations (MICs) from some contemporary isolates exhibited high-level susceptibility to most macrolides and quinolones, and moderate susceptibility to most tetracyclines, whereas other contemporary isolates had high MICs to the same antibiotics. Randomized trials demonstrated poor efficacy of doxycycline and better, but declining, efficacy of single-dose azithromycin therapy. Treatment failures after extended doses of azithromycin similarly increased, and circulating macrolide resistance was present in high levels in several areas. Moxifloxacin remains the most effective therapy, but treatment failures and quinolone resistance are emerging. Surveillance of M. genitalium prevalence and antimicrobial resistance patterns is urgently needed.

Urethral inflammatory response to ureaplasma is significantly lower than to Mycoplasma genitalium and Chlamydia trachomatis

A non-syndromic approach to treatment of people with non-gonococcal urethritis (NGU) requires identification of pathogens and understanding of the role of those pathogens in causing disease. The most commonly detected and isolated micro-organisms in the male urethral tract are bacteria belonging to the family of Mycoplasmataceae, in particular Ureaplasma urealyticum and Ureaplasma parvum. To better understand the role of these Ureaplasma species in NGU, we have performed a prospective analysis of male patients voluntarily attending a drop in STI clinic in Oslo. Of 362 male patients who were tested for NGU using microscopy of urethral smears, we found the following sexually transmissible micro-organisms: 16% Chlamydia trachomatis, 5% Mycoplasma genitalium, 14% U. urealyticum, 14% U. parvum and 5% Mycoplasma hominis. We found a high concordance in detecting in turn U. urealyticum and U. parvum using 16s rRNA gene and ureD gene as targets for nucleic acid amplification testing (NAAT). Whilst there was a strong association between microscopic signs of NGU and C. trachomatis infection, association of M. genitalium and U. urealyticum infections in turn were found only in patients with severe NGU (>30 polymorphonuclear leucocytes, PMNL/high powered fields, HPF). U. parvum was found to colonise a high percentage of patients with no or mild signs of NGU (0–9 PMNL/HPF). We conclude that urethral inflammatory response to ureaplasmas is less severe than to C. trachomatis and M. genitalium in most patients and that testing and treatment of ureaplasma-positive patients should only be considered when other STIs have been ruled out.

Coinfection of Chlamydiae and other Bacteria in Reactive Arthritis and Spondyloarthritis: Need for Future Research

Reactive (inflammatory) arthritis has been known for many years to follow genital infection with the intracellular bacterial pathogen Chlamydia trachomatis in some individuals. Recent studies from several groups have demonstrated that a related bacterium, the respiratory pathogen Chlamydia pneumoniae, can elicit a similar arthritis. Studies of these organisms, and of a set of gastrointestinal pathogens also associated with engendering inflammatory arthritis, have been relatively extensive. However, reports focusing on coinfections with these and/or other organisms, and the effects of such coinfections on the host immune and other systems, have been rare. In this article, we review the extant data regarding infections by multiple pathogens in the joint as they relate to engendering arthritis, and we suggest a number of research areas that must be given a high priority if we are to understand, and therefore to treat in an effective manner, such arthritides.

2016 European guideline on the management of non-gonococcal urethritis

We present the updated International Union against Sexually Transmitted Infections (IUSTI) guideline for the management of non-gonococcal urethritis in men. This guideline recommends confirmation of urethritis in symptomatic men before starting treatment. It does not recommend testing asymptomatic men for the presence of urethritis. All men with urethritis should be tested for Chlamydia trachomatis and Neisseria gonorrhoeae and ideally Mycoplasma genitalium using a nucleic acid amplification test (NAAT) as this is highly likely to improve clinical outcomes. If a NAAT is positive for gonorrhoea, a culture should be performed before treatment. In view of the increasing evidence that azithromycin 1 g may result in the development of antimicrobial resistance in M. genitalium, azithromycin 1 g is no longer recommended as first line therapy, which should be doxycycline 100 mg bd for seven days. If azithromycin is to be prescribed an extended course of 500 mg stat, then 250 mg daily for four days is to be preferred over 1 g stat. In men with persistent NGU, M. genitalium NAAT testing is recommended if not previously undertaken, as is Trichomonas vaginalis NAAT testing in populations where T. vaginalis is detectable in >2% of symptomatic women.

Apparently-Different Clearance Rates from Cohort Studies of Mycoplasma genitalium Are Consistent after Accounting for Incidence of Infection, Recurrent Infection, and Study Design

Mycoplasma genitalium is a potentially major cause of urethritis, cervicitis, pelvic inflammatory disease, infertility, and increased HIV risk. A better understanding of its natural history is crucial to informing control policy. Two extensive cohort studies (students in London, UK; Ugandan sex workers) suggest very different clearance rates; we aimed to understand the reasons and obtain improved estimates by making maximal use of the data from the studies. As M. genitalium is a sexually-transmitted infectious disease, we developed a model for time-to-event analysis that incorporates the processes of (re)infection and clearance, and fitted to data from the two cohort studies to estimate incidence and clearance rates under different scenarios of sexual partnership dynamics and study design (including sample handling and associated test sensitivity). In the London students, the estimated clearance rate is 0.80p.a. (mean duration 15 months), with incidence 1.31%-3.93%p.a. Without adjusting for study design, corresponding estimates from the Ugandan data are 3.44p.a. (mean duration 3.5 months) and 58%p.a. Apparent differences in clearance rates are probably mostly due to lower testing sensitivity in the Uganda study due to differences in sample handling, with 'true' clearance rates being similar, and adjusted incidence in Uganda being 28%p.a. Some differences are perhaps due to the sex workers having more-frequent antibiotic treatment, whilst reinfection within ongoing sexual partnerships might have caused some of the apparently-persistent infection in the London students. More information on partnership dynamics would inform more accurate estimates of natural-history parameters. Detailed studies in men are also required.

Prevalence of M. genitalium and U. urealyticum in urine tested for C. trachomatis

BACKGROUND

Mycoplasma genitalium and Ureaplasma urealyticum cause sexually transmitted infections. While M. genitalium is an established aetiological agent, U. urealyticum is still controversial as a pathogen. Testing for these microbes is not yet widely available in Norway, and knowledge of their prevalence is limited. In this study we have investigated the prevalence of M. genitalium and U. urealyticum in a heterogeneous population from Vestfold and Telemark.

MATERIAL AND METHOD

Urine samples (n = 4,665) received by the laboratory for testing for Chlamydia trachomatis in the period from February 2011 to January 2012 were subsequently tested for M. genitalium and U. urealyticum. Samples were analysed using an in-house PCR protocol.

RESULTS

The prevalence of C. trachomatis, M. genitalium and U. urealyticum was 11.9%, 3.6% and 17.9% respectively. M. genitalium was found most frequently in women aged 20-24 years (5.1%), while the proportion of samples positive for U. urealyticum was greatest in persons aged 15-24 years (22.8%).

INTERPRETATION

M. genitalium was highly prevalent in urine samples submitted for C. trachomatis testing. M. genitalium testing was requested for only a minority of the samples analysed, suggesting limited knowledge of this microbe. U. urealyticum was the most predominant microbe in the study, which may indicate that it is largely non-pathogenic.

Kinetics of Genetic Variation of the Mycoplasma genitalium MG192 Gene in Experimentally Infected Chimpanzees

Mycoplasma genitalium, a human pathogen associated with sexually transmitted diseases, is capable of causing chronic infections, though mechanisms for persistence remain unclear. Previous studies have found that variation of the MgPa operon occurs by recombination of repetitive chromosomal sequences (known as MgPars) into the MG191 and MG192 genes carried on this operon, which may lead to antigenic variation and immune evasion. In this study, we determined the kinetics of MG192 sequence variation during the course of experimental infection using archived specimens from two chimpanzees infected with M. genitalium strain G37. The highly variable region of MG192 was amplified by PCR from M. genitalium isolates obtained at various time points postinfection (p.i.). Sequence analysis revealed that MG192 sequence variation began at 5 weeks p.i. With the progression of infection, sequence changes accumulated throughout the MG192 variable region. The presence of MG192 variants at specific time points was confirmed by variant-specific PCR assays and sequence analysis of single-colony cloned M. genitalium organisms. MG192 nucleotide sequence variation correlated with estimated recombination events, predicted amino acid changes, and time of seroconversion, a finding consistent with immune selection of MG192 variants. In addition, we provided evidence that MG192 sequence variation occurred during the process of M. genitalium single-colony cloning. Such spontaneous variation suggests that some MG192 variation is independent of immune selection but may form the basis for subsequent immune selection.

Usefulness of a novel multiplex real-time PCR assay for the diagnosis of sexually-transmitted infections

INTRODUCTION

Sexually transmitted infections (STI) are currently on the increase worldwide. New molecular tools have been developed in the past few years in order to improve their diagnosis. An evaluation was carried out using a new commercially available real-time PCR assay, Anyplex™ II STI-7 (Seegene, Seoul, Korea), which detects seven major pathogens in a single reaction - Chlamydia trachomatis, Neisseria gonorrhoeae, Trichomonas vaginalis, Mycoplasma hominis, Mycoplasma genitalium, Ureaplasma urealyticum, and Ureaplasma parvum - and compared with conventional methods performed in our laboratory.

MATERIALS AND METHODS

Two different populations were included, and 267 specimens from different sites of infection (urines, endocervical swabs, rectal swabs, vaginal swabs, urethral swabs and one inguinal adenopathy) were processed for both methods.

RESULTS

The parameters of clinical performance were calculated for C. trachomatis, N. gonorrhoeae, and T. vaginalis, and the assay achieved sensitivities (SE) from 93.94% to 100%, and specificities (SP) from 96.55% to 100%, with negative predictive values (NPV) from 93.33% to 98.85%, and positive predictive values (PPV) from 96.88% to 100%, with a very good agreement (kappa index from 0.88 to 1).

CONCLUSIONS

Anyplex™ II STI-7 is a good tool for the reliable diagnosis of STI. Its ease of use and processing allows it to be incorporated into the day to day laboratory work.

Ureaplasma parvum and Mycoplasma genitalium are found to be significantly associated with microscopy-confirmed urethritis in a routine genitourinary medicine setting

Inflammation of the urethra defined by an excess of polymorphonuclear leukocytes in the absence of sexually transmitted Chlamydia trachomatis and Neisseria gonorrhoeae is called non-chlamydial non-gonococcal urethritis (NCNGU). Although Mycoplasma genitalium is now recognised as causing a sexually transmitted infection, the clinical significance of the other Mollicute species is less clear. This study used specific real-time quantitative polymerase chain reaction assays to detect and quantify four Mollicute species, M. genitalium, M. hominis, Ureaplasma urealyticum and U. parvum, in urine specimens from men with and without NCNGU. A total of 165 urine specimens from male patients attending a genitourinary medicine clinic were eligible for the study, with microscopy-confirmed (≥5 polymorphonuclear leukocytes in urethral swab) NCNGU in 75 (45.5%) and non-confirmed NCNGU in 90 (54.5%). Chi-squared statistical analysis indicated a significantly higher prevalence of U. parvum (17.3% vs. 5.6%; p = 0.03) and M. genitalium (12% vs. 0%; p < 0.001) in NCNGU. In a subset analysis, M. genitalium was also significantly (p = 0.03) higher in men who have sex with men (MSM; 13.5%) compared to non-MSM (3.1%). No significant associations were reported for U. urealyticum and M. hominis In conclusion, this study supports a clinically significant role in NGNCU for both U. parvum and M. genitalium.

Management of non-gonococcal urethritis

Non-gonococcal urethritis (NGU), or inflammation of the urethra, is the most common treatable sexually transmitted syndrome in men, with approximately 20-50 % of cases being due to infection with Chlamydia trachomatis and 10-30 % Mycoplasma genitalium. Other causes are Ureaplasma urealyticum, Trichomonas vaginalis, anaerobes, Herpes simplex virus (HSV) and adenovirus. Up to half of the cases are non-specific. Urethritis is characterized by discharge, dysuria and/or urethral discomfort but may be asymptomatic. The diagnosis of urethritis is confirmed by demonstrating an excess of polymorpho-nuclear leucocytes (PMNLs) in a stained smear. An excess of mononuclear leucocytes in the smear indicates a viral etiology. In patients presenting with symptoms of urethritis, the diagnosis should be confirmed by microscopy of a stained smear, ruling out gonorrhea. Nucleid acid amplifications tests (NAAT) for Neisseria gonorrhoeae, C. trachomatis and for M. genitalium. If viral or protozoan aetiology is suspected, NAAT for HSV, adenovirus and T. vaginalis, if available. If marked symptoms and urethritis is confirmed, syndromic treatment should be given at the first appointment without waiting for the laboratory results. Treatment options are doxycycline 100 mg x 2 for one week or azithromycin 1 gram single dose or 1,5 gram distributed in five days. However, azithromycin as first line treatment without test of cure for M. genitalium and subsequent Moxifloxacin treatment of macrolide resistant strains will select and increase the macrolide resistant strains in the population. If positive for M. genitalium, test of cure samples should be collected no earlier than three weeks after start of treatment. If positive in test of cure, moxifloxacin 400 mg 7-14 days is indicated. Current partner(s) should be tested and treated with the same regimen. They should abstain from intercourse until both have completed treatment. Persistent or recurrent NGU must be confirmed with microscopy. Reinfection and compliance must be considered. Evidence for the following recommendations is limited, and is based on clinical experience and guidelines. If doxycycline was given as first therapy, azithromycin five days plus metronidazole 4-500 mg twice daily for 5-7 days should be given. If azithromycin was prescribed as first therapy, doxycycline 100 mg x 2 for one week plus metronidazole, or moxifloxacin 400 mg orally once daily for 7-14 days should be given.

2015 UK National Guideline on the management of non-gonococcal urethritis

We present the updated British Association for Sexual Health and HIV guideline for the management of non-gonococcal urethritis in men. This document includes a review of the current literature on its aetiology, diagnosis and management. In particular it highlights the emerging evidence that azithromycin 1 g may result in the development of antimicrobial resistance in Mycoplasma genitalium and that neither azithromycin 1 g nor doxycycline 100 mg twice daily for seven days achieves a cure rate of >90% for this micro-organism. Evidence-based diagnostic and management strategies for men presenting with symptoms suggestive of urethritis, those confirmed to have non-gonococcal urethritis and those with persistent symptoms following first-line treatment are detailed.

Diagnosis and antimicrobial treatment of Mycoplasma genitalium infection: sobering thoughts

The discovery of Mycoplasma genitalium in 1980-1981 eventually led to it becoming recognized as an important cause of non-gonococcal urethritis in men and also some genital tract diseases in women. Subsequent to the original isolation, further attempts failed over the next decade and reliable detection only became possible with the use of nucleic acid amplification techniques. Although tetracyclines, particularly doxycycline, were the first choice for treatment of non-gonococcal urethritis prior to the finding of M. genitalium, they were unsatisfactory for the treatment of M. genitalium-associated disease; the organisms were often not eliminated leading, for example, to chronic urethritis. However, the introduction of azithromycin, used as single-dose therapy for chlamydial infections, resulted in clearance of the mycoplasmal organisms from the genital tract and clinical recovery without the development of chronic disease. Nevertheless, such success was short-lived as M. genitalium, through mutation, began to develop resistance to azithromycin and M. genitalium mutants also began to circulate in some populations. In an attempt to counteract this, clinicians should give extended therapy, and in the future, microbiologists, using real-time PCRs, might be able to determine the existence of resistant strains in the local population and so advise on the most appropriate antibiotic. Other than azithromycin, there are a few options, moxifloxacin being one, although the recently reported resistance to this antibiotic is disturbing. In the short to medium term, combination therapy and/or the advent of a new antibiotic might abate the spread of resistance, but in the long term, there is potential for increasing prevalence of untreatable M. genitalium disease. In the future, attempts to develop a vaccine and, of equal importance, one to Chlamydia trachomatis, would not be out of place.

Are Ureaplasma spp. a cause of nongonococcal urethritis? A systematic review and meta-analysis

Background

Nongonococcal urethritis (NGU) is the most common male reproductive tract syndrome. Ureaplasmas spp. including U. urealyticum and U. parvum, have been increasingly reported to be implicated in NGU. However, there are still many contradictions about their pathogenic role in NGU.

Aims

The goals of this study were to evaluate the association of Ureaplasmas spp. with NGU, and to compare the prevalence of Ureaplasmas spp. infection in China relative to the world average.

Methods

A systematic review and meta-analysis was conducted following standard guidelines for meta-analysis. The quality of included studies was assessed by Newcastle-Ottawa scale.

Results

A total of seven studies involving 1,507 NGU patients and 1,223 controls were eligible for meta-analysis. There was no significant difference in the Ureaplasma spp. positive rate between the NGU and control groups. However, the U. urealyticum positive rate was significantly higher in NGU patients compared to controls; the U. parvum positive rate was significantly higher in controls compared to NGU patients. Furthermore, within the NGU patient group, the positive rate of U. urealyticum was significantly higher than that of U. parvum, whereas within the control group, the opposite trend was observed. Compared to the world average, a significantly higher positive rate of Ureaplasma spp. was observed in both the NGU and control groups in China.

Conclusions

Our analysis supports that U. urealyticum, but not U. parvum, is an etiological agent in NGU. More detailed studies of these two species in China and the world could contribute to a better understanding of the epidemiology and pathogenesis, and facilitate the development of better strategies for treatment and prevention of NGU.

Comparison between culture and a multiplex quantitative real-time polymerase chain reaction assay detecting Ureaplasma urealyticum and U. parvum

A novel multiplex quantitative real-time polymerase chain reaction (qPCR) for simultaneous detection of U. urealyticum and U. parvum was developed and compared with quantitative culture in Shepard's 10 C medium for ureaplasmas in urethral swabs from 129 men and 66 women, and cervical swabs from 61 women. Using culture as the gold standard, the sensitivity of the qPCR was 96% and 95% for female urethral and cervical swabs, respectively. In male urethral swabs the sensitivity was 89%. The corresponding specificities were 100%, 87% and 99%. The qPCR showed a linear increasing DNA copy number with increasing colour-changing units. Although slightly less sensitive than culture, this multiplex qPCR assay detecting U. urealyticum and U. parvum constitutes a simple and fast alternative to the traditional methods for identification of ureaplasmas and allows simultaneous species differentiation and quantitation in clinical samples. Furthermore, specimens overgrown by other bacteria using the culture method can be evaluated in the qPCR.

Prevalence of Trichomonas vaginalis, Mycoplasma genitalium and Ureaplasma urealyticum in men with urethritis attending an urban sexual health clinic

We conducted a study to determine the prevalence of Trichomonas vaginalis (TV), Mycoplasma genitalium (MG) and Ureaplasma urealyticum (UU) in men with urethritis, attending an urban sexual health clinic, in order to inform screening and treatment policies. Men attending an urban sexual health clinic between June 2011 and January 2012 were evaluated. Urine samples were collected from men with urethritis and tested for Chlamydia trachomatis (CT), Neisseria gonorrhoeae (GC) and TV using transcription-mediated amplification and for MG and UU using polymerase chain reaction. Eighty-three samples were analysed. The prevalence of CT was 33.7% (28/83), GC was 16.8% (14/83), TV was 3.6% (3/83), MG was 12.0% (10/83) and UU was 4.8% (4/83). Fifteen men had recurrent urethritis. Of these, three were found to have had TV, five to have had MG and none to have had UU, at initial presentation. Given the prevalence of MG in this study, there is an urgent need for further larger studies looking at optimal treatment regimens and screening strategies in urethritis.

Observations on Chlamydia trachomatis and other microbes in reactive arthritis

There are problems in attributing causality in inflammatory arthritis. So far as C. trachomatis and sexually acquired reactive arthritis are concerned, there is much in favour of a causal relationship, although there are important caveats which need to be explored before it is possible to say unreservedly that C. trachomatis plays a causative role in reactive arthritis. For example, micro-organisms have never been cultured from synovial effusions in early disease, and only once has substantial benefit of antimicrobial treatment been reported. The claim that ocular strains of C. trachomatis are of over-riding importance in pathogenesis needs confirmation before it can be accepted. No conclusion can be made about the possibility of other small intracellular bacteria in joints having a role in causing disease. However, if it can be shown that eradication of the micro-organism, which may be difficult to prove, coincides with clinical recovery, it would go some way to recognising causality. In spite of the recognised difficulties, antibiotic studies have an important role in identifying aetiology. They need to focus on very early disease and on eradication of intra-articular bacteria. Treatment of established disease is likely to be less informative. Although a combination of antibiotics might have a future in treating established disease, diagnosing and treating non-gonococcal urethritis as soon as possible should be the aim in order to prevent the development of reactive arthritis.

Natural history of Mycoplasma genitalium infection in a cohort of female sex workers in Kampala, Uganda

BACKGROUND

There have been few studies of the natural history of Mycoplasma genitalium in women. We investigated patterns of clearance and recurrence of untreated M. genitalium infection in a cohort of female sex workers in Uganda.

METHODS

Women diagnosed as having M. genitalium infection at enrollment were retested for the infection at 3-month intervals. Clearance of infection was defined as testing negative after having a previous positive result: persistence was defined as testing positive after a preceding positive test result, and recurrence as testing positive after a preceding negative test result. Adjusted hazard ratios for M. genitalium clearance were estimated using Cox proportional hazards regression.

RESULTS

Among 119 participants infected with M. genitalium at enrollment (prevalence, 14%), 55% had spontaneously cleared the infection within 3 months; 83%, within 6; and 93%, within 12 months. The overall clearance rate was 25.7/100 person-years (pyr; 95% confidence interval, 21.4-31.0). HIV-positive women cleared M. genitalium infection more slowly than did HIV-negative women (20.6/100 pyr vs. 31.3/100 pyr, P = 0.03). The clearance rate was slower among HIV-positive women with CD4 counts less than 350/mL than among those with higher CD4 counts (9.88/100 pyr vs. 29.5/100 pyr, P <; 0.001). After clearing the infection, M. genitalium infection recurred in 39% women.

CONCLUSIONS

M. genitalium is likely to persist and recur in the female genital tract. Because of the urogenital tract morbidity caused by the infection and the observed association with HIV acquisition, further research is needed to define screening modalities, especially in populations at high risk for HIV, and to optimize effective and affordable treatment options.

Mycoplasma genitalium: An emergent sexually transmitted disease?

This article summarizes the epidemiologic evidence linking Mycoplasma genitalium to sexually transmitted disease syndromes, including male urethritis, and female cervicitis, pelvic inflammatory disease, infertility, and adverse birth outcomes. It discusses the relationship of this bacterium to human immunodeficiency virus infection and reviews the available literature on the efficacy of standard antimicrobial therapies against M genitalium.

Fluoroquinolone and macrolide resistance-associated mutations in Mycoplasma genitalium

Mycoplasma genitalium is a significant sexually transmitted pathogen, causing up to 25% of cases of nongonococcal urethritis in men, and it is strongly associated with cervicitis and pelvic inflammatory disease in women. Currently, the usual first-line treatment is the macrolide antibiotic azithromycin, but an increasing incidence of treatment failure over the last 5 years suggests the emergence of antibiotic resistance. The mutations responsible for macrolide resistance have been found in the 23S rRNA gene in numerous M. genitalium populations. A second-line antibiotic, the fluoroquinolone moxifloxacin, was thought to be a reliable alternative when azithromycin began to fail, but recent studies have identified mutations that may confer fluoroquinolone resistance in the genes parC and gyrA. The aim of this study was to determine the prevalence of antibiotic resistance in M. genitalium in Sydney, Australia, by detecting relevant mutations in the 23S rRNA gene, parC, and gyrA. M. genitalium-positive DNA extracts of specimens, collected from patients attending sexual health clinics in Sydney, were tested by PCR amplification and DNA sequence alignment. The 186 specimens tested included 143 initial patient specimens and 43 second, or subsequent, specimens from 24 patients. We identified known macrolide resistance-associated mutations in the 23S rRNA gene in 43% of the initial patient samples and mutations potentially associated with fluoroquinolone resistance in parC or gyrA sequences in 15% of the initial patient samples. These findings support anecdotal clinical reports of azithromycin and moxifloxacin treatment failures in Sydney. Our results indicate that further surveillance is needed, and testing and treatment protocols for M. genitalium infections may need to be reviewed.

Urethritis and antimicrobial resistance

Urethritis is a clinical syndrome which is characterized by mucopurulent or purulent urethral discharge with or without dysuria, due to an increased number of polymorphonuclear leukocytes in the anterior urethra. Antimicrobial therapy and preventive measures are essential in the management of bacterial urethritis. However, these drugs may cause antimicrobial resistance, resulting in unsuccessful treatment and complications of urethritis. Resistance of Neisseria gonorrhoeae to antibiotics is well known for decades, and in recent years there are more cases of resistance of Chlamydia trachomatis and Mycoplasma genitalium to different antibiotics. There is a danger that in the future certain strains of N. gonorrhoeae will be resistant to all available antimicrobial agents, unless new antibiotics to which resistance will not develop rapidly or an effective vaccine are developed.

Mycoplasma genitalium, an emerging sexually transmitted pathogen

Mycoplasma genitalium is a sexually transmitted organism associated with non-gonococcal urethritis in men and several inflammatory reproductive tract syndromes in women such as cervicitis, pelvic inflammatory disease, and infertility. There was evidence for an association of M. genitalium with endometritis and pelvic inflammatory disease (PID), but additional studies are necessary to confirm this. The evidence as to whether M. genitalium can cause adverse pregnancy outcomes such as preterm labor is conflicting. But the authors of some studies on M. genitalium as a cause of infertility have reported this association. This species is very difficult to culture; thus, nucleic acid amplification testing is the only method available for M. genitalium detection. The lack of a cell wall makes M. genitalium intrinsically resistant to antibiotics acting at this level, such as beta-lactams. The treatment of M. genitalium infections is not standardized. Macrolides are recommended, especially single-dose azithromycin; tetracyclines are responsible for a great number of therapeutic failures even no resistance mechanism has yet been demonstrated. Acquired resistance to macrolides and fluoroquinolones leading to therapeutic failure has also been reported. All this raises the issue of the most appropriate therapeutic management and requires drafting diagnostic and therapeutic guidelines for the treatment of M. genitalium infections.

Genital mycoplasma & Chlamydia trachomatis infections in treatment naïve HIV-1 infected adults

Background & objectives:

Sexually transmitted infections (STIs) enhance the transmission of human immunodeficiency virus (HIV). Thus, screening for STIs is a routine component of primary HIV care. There are limited data for selective screening guidelines for genital mycoplasmas and Chlamydia trachomatis in HIV-infected adults. The aim of the present study was to determine the frequency of genital infections with Ureaplasma spp., Mycoplasma hominis, M. genitalium and C. trachomatis in treatment naïve asymptomatic HIV-1 - infected adults and study their association with CD4+ T-cell count.

Methods:

First-void urine samples were collected from 100 treatment-naïve HIV-1-infected adults and 50 healthy volunteers. C. trachomatis and M. genitalium were detected by polymerase chain reaction (PCR). Ureaplasma spp. and M. hominis were detected by both culture and PCR. Circulating CD4+ cell counts of HIV-1-infected patients were determined from peripheral blood by flow-cytometry.

Results:

C. trachomatis was detected in 7 per cent of HIV-1-infected adults compared to none in control population. Ureaplasma spp. and M. hominis showed infection rates of 6 and 1 per cent in the HIV group and 2 and 0 per cent in the control group, respectively. None of the individuals from the patient and control groups was tested positive for M. genitalium. A significant association was found between CD4 cell count and detection of C. trachomatis in HIV-infected adults (P = 0.01).

Interpretation & conclusions:

Screening of HIV-infected individuals for C. trachomatis infection could be recommended as a routine component of HIV care. The role of mycoplasmas as co-pathogens of the genitourinary tract in HIV-1 infected patients seems to be unlikely. Further longitudinal studies need to be done to confirm these findings.

A comprehensive proteome of Mycoplasma genitalium

Mycoplasma genitalium is a human pathogen associated with several sexually transmitted diseases. Proteomic technologies, along with other methods for global gene expression analysis, play a key role in understanding the mechanisms of bacterial pathogenesis and physiology. The proteome of M. genitalium, model of a minimal cell, has been extended using a combination of different proteomic approaches and technologies. The total proteome of this microorganism has been analyzed using gel-based and gel-free approaches, achieving the identification of 85.3% of the predicted ORFs. In addition, a comprehensive analysis of membrane subproteome has been performed. For this purpose, the TX-114 soluble fraction has been analyzed as well as the surface proteins, using cell-surface protein labeling with CyDye. Finally, the serological response of M. genitalium-infected patients and healthy donors has been analyzed to identify proteins that trigger immunological response. Here, we present the most extensive M. genitalium proteome analysis (85.3% of predicted ORFs), a comprehensive M. genitalium membrane analysis, and a study of the human serological response to M. genitalium.

Evidence for the predominance of a single tet(M) gene sequence type in tetracycline-resistant Ureaplasma parvum and Mycoplasma hominis isolates from Tunisian patients

Resistance to tetracyclines in genital mycoplasmas is due mainly to acquisition of the tet(M) determinant, which is frequently associated with conjugative transposon elements of the Tn916/Tn1545 family. The aim of the present work was to evaluate the prevalence of tet(M) in Tunisian isolates and to gain an insight into its origin and evolution. Twenty Ureaplasma parvum, two Ureaplasma urealyticum and 48 Mycoplasma hominis isolates, recovered from Tunisian patients with urogenital and infertility disorders, were evaluated for their resistance to tetracyclines and interrogated by PCR amplification for the presence of tet(M) and int-Tn, the gene encoding the integrase of Tn916/Tn1545-like transposons. The resistance rates to tetracyclines were 22.72 and 25.0 % among U. parvum and M. hominis isolates, respectively, with high-level resistance observed in 11 of the 12 resistant M. hominis isolates. All resistant isolates harboured both tet(M) and int-Tn sequences. Nucleotide sequence analysis of the tet(M) amplicon revealed a unique sequence shared by all tetracycline-resistant clinical isolates of both species. Molecular typing indicated that the tetracycline-resistant U. parvum and M. hominis isolates were not clonal. Taken together, these data indicate that a single tet(M) gene sequence type, most probably transmitted via a Tn916/Tn1545-like transposon, contributes to most of the tetracycline resistance in U. parvum and M. hominis isolates in Tunisia. Because this tet(M) gene sequence type was harboured by different Mycoplasma spp. and by phylogenetically distinct isolates within these species, one could reasonably argue that it may have benefited from an efficient horizontal transfer context, making it highly competent to spread.

[Microbiological diagnosis of mycoplasma infections]

The microbiological diagnosis of mycoplasma and ureaplasma infections has always been limited due to the fastidious growth of these microorganisms, as well as the lack of commercially prepared growth media, absence of rapid diagnostic procedures, and the clinical perception that these organisms are less significant in the infectious diseases setting. During the last few years, this situation has substantially improved due to the commercial availability of culture media, the development of rapid serological techniques, and, in particular, to the introduction of nucleic acid amplification assays, commercially available or "in-house" preparations. Despite the lack of proper standardisation and validation of the molecular and serological techniques, methodological advances have led to an increased detection of these microorganisms and, consequently, a greater appreciation of their clinical relevance.

Frequency of Chlamydia trachomatis in Ureaplasma-positive healthy women attending their first prenatal visit in a community hospital in Sapporo, Japan

BACKGROUND

Although Chlamydia trachomatis is the most commonly reported pathogen that causes urogenital infection such as urethritis or cervicitis, Ureaplasma parvum and Ureaplasma urealyticum, which are commensals in the genital tract, have also now been recognized as contributors to urogenital infection. However, whether the presence of either U. parvum or U. urealyticum is related to that of C. trachomatis in the urogenital tract remains unknown. We therefore attempted to estimate by PCR the prevalence of C. trachomatis, U. parvum and U. urealyticum in endocervical samples obtained from healthy women attending their first prenatal visit in Sapporo, Japan.

METHODS

The samples were taken from 303 apparently healthy women, and the extracted DNAs (n = 280) were used for PCR detection targeting C. trachomatis, U. parvum and U. urealyticum. Statistical analysis of the data was performed by Fisher's exact test.

RESULTS

PCR detection revealed that the prevalence of C. trachomatis, U. parvum and U. urealyticum was 14.3% (40/280), 41.7% (117/280) and 8.9% (25/280), respectively. C. trachomatis ompA genotype D was most frequently identified. Surprisingly, either C. trachomatis or Ureaplasma spp. was detected in almost half of the healthy women. Mixed infection of C. trachomatis with either U. parvum or U. urealyticum was also observed in 9.2% (26/280) of the women. There was a significant association between C. trachomatis and either U. parvum (p = 0.023) or Ureaplasma total (p = 0.013), but not U. urealyticum (p = 0.275).

CONCLUSION

This study demonstrated that the presence of Ureaplasma had a significant effect on the presence of C. trachomatis in the genital tract of healthy women, suggesting that mixed infection is an important factor in bacterial pathogenesis in the genital tract.