Prevalence of rectal Mycoplasma genitalium and macrolide resistance in men who have sex with men attending Sydney Sexual Health Centre.

Background Sexually transmissible infections (STIs) have been increasing in men who have sex with men (MSM) in recent years; however, few studies have investigated the prevalence or antimicrobial resistance in rectal Mycoplasma genitalium in this group. This study aimed to determine the prevalence and predictors of rectal M. genitalium in MSM attending an urban sexual health service in Sydney, Australia, namely the Sydney Sexual Health Centre (SSHC), as well as estimate the rate of macrolide resistance. METHODS: A prospective cross-sectional analysis was conducted of rectally asymptomatic MSM having a rectal swab collected as part of their routine care. Participants self-collected a rectal swab to be tested for M. genitalium and completed a 14-item questionnaire that provided information on behavioural risk factors. The prevalence of rectal M. genitalium was determined and multivariate analysis was performed to assess the associations for this infection. Positive specimens then underwent testing for macrolide-resistant mutations (MRMs) using the ResistancePlus MG assay (SpeeDx, Eveleigh, NSW, Australia). RESULTS: In all, 742 patients were consecutively enrolled in the study. The median age was 31 years (interquartile range 27-39 years), with 43.0% born in Australia. Overall, 19.0% of men were bisexual, 22.9% were taking pre-exposure prophylaxis (PrEP) and 4.3% were HIV positive. The prevalence of rectal M. genitalium was 7.0% (95% confidence interval (CI) 5.3-9.1) overall and 11.8% in those taking PrEP. On multivariate analysis, PrEP use was significantly associated with having rectal M. genitalium (odds ratio 2.01; 95% CI 1.09-3.73; P = 0.01). MRMs were detected in 75.0% (36/48; 95% CI 60.4-86.4%) of infections. CONCLUSION: Rates of rectal M. genitalium infection were high among asymptomatic MSM attending SSHC and MRMs were detected in 75% of infections. PrEP use was found to be significantly associated with rectal M. genitalium infection. These data contribute to the evidence base for screening guidelines in MSM.

Men Who Have Sex With Men With Mycoplasma genitalium-Positive Nongonococcal Urethritis Are More Likely to Have Macrolide-Resistant Strains Than Men With Only Female Partners: A Prospective Study.

BACKGROUND: Mycoplasma genitalium was previously less common among men who have sex with men (MSM) compared with men with only female partners (MSW) in men with nongonococcal urethritis (NGU) in Sydney, Australia. We aimed to determine the prevalence of M. genitalium and of macrolide-resistant M. genitalium in men with NGU and to compare differences between prevalence and resistance rates between MSM and MSW. METHODS: We enrolled 588 men with NGU in a prospective study at two urban sexual health services. The ResistancePlus MG assay (SpeeDx, Australia) was used to detect both M. genitalium, and macrolide resistance-associated mutations in first-void urine samples. Demographic, behavioral and clinical data were analyzed to investigate associations with M. genitalium infection or the presence of macrolide resistance. RESULTS: Mycoplasma genitalium prevalence was 12.8% (75 of 588) overall and among MSM (12.8% [39 of 306]) and MSW (12.8% [36 of 282]; risk ratio [RR], 1.00; 95% confidence interval [CI], 0.65-1.52). Overall, 70.7% (53 of 75) of M. genitalium strains were macrolide-resistant, with significantly more resistance among MSM (89.7%, 35 of 39) than MSW (50%, 18 of 36) (RR, 1.80; 95% CI, 1.27-2.54; P = 0.001). On multivariate analysis, the presence of M. genitalium macrolide resistance mutations was independently associated with having male sexual partners compared with having only female partners (RR, 1.55; 95% CI, 1.02-2.38; P = 0.042). CONCLUSIONS: Prevalence of M. genitalium among men with NGU is now similar for MSW and MSM and has increased locally from 5.2% to 12.8% within the last 10 years. Men who have sex with men are significantly more likely than MSW to harbor macrolide-resistant M. genitalium infections. This has treatment implications.

Mycoplasma genitalium: high prevalence of resistance to macrolides and frequent anorectal infection in men who have sex with men in western Sydney.

OBJECTIVES: We aimed to estimate the prevalence of Mycoplasma genitalium infection and of mutations linked to macrolide resistance using the ResistancePlus MG assay (SpeeDx, Sydney, New South Wales, Australia) in first-void urine (FVU), anorectal and oropharyngeal samples from men who have sex with men (MSM) attending Western Sydney Sexual Health Centre (WSSHC). METHODS: Consecutive symptomatic and asymptomatic MSM attending for STI testing were prospectively enrolled. M. genitalium testing using the ResistancePlus MG assay was performed on FVU, anorectal and oropharyngeal samples routinely collected for Chlamydia trachomatis and Neisseria gonorrhoeae assays. RESULTS: Overall, the prevalence of M. genitalium infection in the study group was 13.4% (68/508). Most (79.4%, 54/68) M. genitalium harboured macrolide resistance mutations (87.5% of urethral and 75.6% of anorectal infections). The anorectum was the most commonly infected site (45/505, 8.9%), followed by the urethra (24/508, 4.7%). No oropharyngeal M. genitalium infections were detected (0/508). Most of the anorectal (93.3%) and urethral (79.2%) infections were asymptomatic.MSM who were taking HIV pre-exposure prophylaxis (PrEP) were twice as likely to be infected with M. genitalium compared with MSM who were not on PrEP (OR 2.1, 95% CI 1.3 to 3.6; P=0.0041). Always using condoms for anal sex in the last 3 months was protective of infection (OR 0.8, 95% CI 0.6 to 1.0; P=0.0186). CONCLUSIONS: We demonstrated a high prevalence of M. genitalium and very high levels of macrolide resistance among MSM attending WSSHC. Our findings support the routine use of an assay to detect macrolide resistance mutations in M. genitalium infections. This will ensure, in regions or populations with high rates of macrolide resistance among M. genitalium strains, that first-line treatment with azithromycin will only be used if a macrolide-sensitive strain is identified.