Prevalence of Mycoplasma genitalium by anatomical site in men who have sex with men: a systematic review and meta-analysis.

OBJECTIVE: To systematically review and appraise published data, to determine the prevalence of Mycoplasma genitalium (MG) in men who have sex with men (MSM) tested at each anatomical site, that is, at the urethra, rectum and/or pharynx. DESIGN: Systematic review and meta-analysis. DATA SOURCES: Ovid Medline, PubMed, Embase were searched for articles from 1st January 1981 (the year MG was first identified) to 1st June 2018. REVIEW METHODS: Studies were eligible for inclusion if they reported MG prevalence in MSM tested at the urethra, rectum and/or pharynx, in at least 50 MSM, using nucleic acid amplification testing. Data were extracted by anatomical site, symptom and HIV status. Summary estimates (95% CIs) were calculated using random-effects meta-analysis. Subgroup analyses were performed to assess heterogeneity between studies. RESULTS: Forty-six studies met inclusion criteria, with 34 reporting estimates of MG prevalence at the urethra (13 753 samples), 25 at the rectum (8629 samples) and 7 at the pharynx (1871 samples). MG prevalence was 5.0% (95% CI 3.5 to 6.8; I2=94.0) at the urethra; 6.2% (95% CI 4.6 to 8.1; I2=88.1) at the rectum and 1.0% (95% CI 0.0 to 5.1; I2=96.0) at the pharynx. The prevalence of MG was significantly higher at urethral and rectal sites in symptomatic versus asymptomatic MSM (7.1% vs 2.2%, p<0.001; and 16.1% vs 7.5%, p=0.039, respectively). MG prevalence at the urethra was significantly higher in HIV-positive compared with HIV-negative MSM (7.0% vs 3.4%, p=0.006). CONCLUSION: MG was common in MSM, particularly at urethral and rectal sites (5% to 6%). MG was more commonly detected in symptomatic men at both sites, and more common in HIV-positive men at the urethra. MG was uncommonly detected in the pharynx. Site-specific estimates are similar to those for chlamydia and will be helpful in informing testing practices in MSM. PROSPERO REGISTRATION NUMBER: CRD42017058326.

Mycoplasma genitalium incidence, persistence, concordance between partners and progression: systematic review and meta-analysis.

BACKGROUND: Mycoplasma genitalium is increasingly seen as an emerging sexually transmitted pathogen, and has been likened to Chlamydia trachomatis, but its natural history is poorly understood. The objectives of this systematic review were to determine M. genitalium incidence, persistence, concordance between sexual partners and the risk of pelvic inflammatory disease (PID). METHODS: We searched Medline, EMBASE, LILACS, IndMed and African Index Medicus from 1 January 1981 until 17 March 2018. Two independent researchers screened studies for inclusion and extracted data. We examined results in forest plots, assessed heterogeneity and conducted meta-analysis where appropriate. Risk of bias was assessed for all studies. RESULTS: We screened 4634 records and included 18 studies; six (4201 women) reported on incidence, five (636 women) on persistence, 10 (1346 women and men) on concordance and three (5139 women) on PID. Incidence in women in two very highly developed countries was 1.07 per 100 person-years (95% CI 0.61 to 1.53, I2 0%). Median persistence of M. genitalium was estimated from one to three months in four studies but 15 months in one study. In 10 studies measuring M. genitalium infection status in couples, 39%-50% of male or female sexual partners of infected participants also had M. genitalium detected. In prospective studies, PID incidence was higher in women with M. genitalium than those without (risk ratio 1.73, 95% CI 0.92 to 3.28, I2 0%, two studies). DISCUSSION: Incidence of M. genitalium in very highly developed countries is similar to that for C. trachomatis, but concordance might be lower. Taken together with other evidence about age distribution and antimicrobial resistance in the two infections, M. genitalium is not the new chlamydia. Synthesised data about prevalence, incidence and persistence of M. genitalium infection are inconsistent. These findings can be used for mathematical modelling to investigate the dynamics of M. genitalium. REGISTRATION NUMBERS: CRD42015020420, CRD42015020405.

Dissociation between learning and memory impairment and other sickness behaviours during simulated Mycoplasma infection in rats.

To investigate potential consequences for learning and memory, we have simulated the effects of Mycoplasma infection, in rats, by administering fibroblast-stimulating lipopepide-1 (FSL-1), a pyrogenic moiety of Mycoplasma salivarium. We measured the effects on body temperature, cage activity, food intake, and on spatial learning and memory in a Morris Water Maze. Male Sprague-Dawley rats had radio transponders implanted to measure abdominal temperature and cage activity. After recovery, rats were assigned randomly to receive intraperitoneal (I.P.) injections of FSL-1 (500 or 1000 µg kg(-1) in 1 ml kg(-1) phosphate-buffered saline; PBS) or vehicle (PBS, 1 ml kg(-1)). Body mass and food intake were measured daily. Training in the Maze commenced 18 h after injections and continued daily for four days. Spatial memory was assessed on the fifth day. In other rats, we measured concentrations of brain pro-inflammatory cytokines, interleukin (IL)-1ß and IL-6, at 3 and 18 h after injections. FSL-1 administration induced a dose-dependent fever (∼1°C) for two days, lethargy (∼78%) for four days, anorexia (∼65%) for three days and body mass stunting (∼6%) for at least four days. Eighteen hours after FSL-1 administration, when concentrations of IL-1ß, but not that of IL-6, were elevated in both the hypothalamus and the hippocampus, and when rats were febrile, lethargic and anorexic, learning in the Maze was unaffected. There also was no memory impairment. Our results support emerging evidence that impaired learning and memory is not inevitable during simulated infection.

Intracerebral administration of Mycoplasma fermentans produces sickness behavior: role of prostaglandins.

Mycoplasmas are small microorganisms, which cause various diseases in animals and in humans, activate the immune system, and induce the release of various cytokines. Some of the effects of mycoplasmas are mediated by the CNS. Moreover, Mycoplasma fermentans (MF) has recently been found in the brain, as well as other tissues of some AIDS patients, who usually display severe neurobehavioral disturbances. The present study was designed to examine the behavioral effects of central administration of MF, and the role of prostaglandins in mediating these effects. In one set of experiments, rats were injected intracerebroventricularly (i.c.v.) with either saline or a dose of MF (5.1-36 microg per rat), and several behavioral parameters were measured. In addition, body temperature and locomotor activity were continuously monitored by a biotelemetric system. MF induced a significant elevation in body temperature and suppression of motor activity levels. MF also significantly reduced the time spent in social exploration, decreased locomotor and exploratory activity in the open field test, suppressed the consumption of food and saccharine solution, and reduced body weight. In a second set of experiments, i.c.v. administration of MF (7.2 microg) was found to produce a significant increase in the production of prostaglandin E2 (PGE2) in hypothalamic, hippocampal, and cortical tissues. This effect was blocked by indomethacin, a prostaglandin synthesis inhibitor. Indomethacin also attenuated the effects of MF on body temperature, motor activity and body weight, suggesting the involvement of prostaglandins in mediating some of the effects of MF. Together, these findings suggest that the presence of MF in the brain may be responsible for some of the neurobehavioral abnormalities in HIV-infected patients.

Sexual risk behaviour in women carriers of Mycoplasma hominis.

OBJECTIVE: To study the sexual behaviour of women harbouring Mycoplasma hominis in the vagina. SETTING: Two family planning clinics and a youth clinic for contraceptive advice. METHODS: The vaginal flora of 996 women were investigated microbiologically, including culturing for M. hominis from the posterior vaginal fornix. Cultures and tests were also made to diagnose genital Chlamydia trachomatis infections, gonorrhoea, genital herpes, cervical human papillomavirus infection, trichomoniasis, genital warts and human immunodeficiency virus. The sexual behaviour of these women was investigated by structured in-depth personal interviews. RESULTS: Of the 996 women, 123 (12.3%) harboured M. hominis in the vagina. The remainder (87.7%), who had a negative M. hominis culture, served as a reference group. Those with M. hominis were significantly more likely to have had more than 10 partners during their lifetime, had a greater frequency of more than one sexual partner during the preceding month and the last six months, and reported more frequent experience of "casual sex', including casual "travel sex'. More of them also had experience of group sex and were more likely to have been sexually abused than the women in the reference group. Fewer women with M. hominis had a current steady partner and were less often cohabitors, but more had had sexual intercourse during the previous week than those in the reference group. There was an association between the occurrence of M. hominis and bacterial vaginosis and genital chlamydial infection. Adjustment in multifactorial regression analyses therefore changed the results only marginally. CONCLUSIONS: Women with M. hominis have almost the same sexual risk behaviour as women with classic sexually transmitted diseases.

The influence of social rank on the susceptibility of rats to Mycoplasma arthritidis.

Social ranks (A, O, rest) of adult male inbred rats housed in groups of four per cage were determined by repeated observations of their ejaculatory patterns under competitive conditions. Once ranked, they were intravenously infected. Fifteen clinical, hematological, and serological characters were continuously observed during 110 days. Body weight reduction, arthritis score, and specific IgG antibody titers were chosen as guideline characteristics and compared between different genotypes and social rank classes. Genotypic differences account for 60-80% of the individual differences and social rank differences account for 0-40% of the individual differences within isogenic animals. Social rank affects the individual genotypes in an opposite way. Rank A males are less susceptible in genotype DA but showed increased susceptibility in genotypes AS. In genotype LEW, influence of social rank on susceptibility to Mycoplasma arthritidis could not be verified. Specific IgG antibody titers are lower in ranks showing a higher degree of susceptibility.