Recent advances in understanding and combatting Mycoplasma genitalium

Mycoplasma genitalium infection among gay, bisexual and other men who have sex with men in Montréal, Canada

Background

The bacteria Mycoplasma genitalium has been identified as a causative agent of urethritis in men, especially in gay, bisexual and other men who have sex with men (gbMSM). Canadian clinic-based data have identified a high prevalence of M. genitalium and resistance to antibiotic treatments. This article estimates the prevalence of M. genitalium infections among Montréal gbMSM, explores correlates for M. genitalium infection and estimates the prevalence of mutations associated with antimicrobial resistance (AMR).

Methods

Engage Cohort Study is a multi-site longitudinal study on sexually active gbMSM, aged 16 years and older, recruited via respondent-driven sampling in Montréal, Toronto and Vancouver. Participants completed a questionnaire on behaviour and were tested for sexually transmitted and blood-borne infections at each visit. For this sub-study, Montréal participants with a follow-up visit that occurred between November 2018 and November 2019 were included.

Results

A total of 2,064 samples were provided by 716 participants. Prevalence of M. genitalium infection was 5.7% at rectal and/or urethral sites, 4.0% at rectal site and 2.2% at urethral site. Correlates for M. genitalium infection were younger age and reporting six or more sexual partners in the past six months. Prevalence of macrolide resistance associated mutations (MRAM), quinolone resistance associated mutations (QRAM) and either MRAM or QRAM, was 82%, 29% and 85%, respectively.

Conclusion

This first population-based study among gbMSM in Canada documents a high prevalence of urethral and rectal M. genitalium infection and high levels of AMR. Our results highlight the importance of access to testing and AMR detection when indicated.

Update in Epidemiology and Management of Mycoplasma genitalium Infections

Mycoplasma genitalium is a frequent cause of urogenital syndromes in men and women and is associated with adverse sequelae in women. M genitalium also infects the rectum, and may cause proctitis, but rarely infects the pharynx. Diagnosis requires nucleic acid amplification testing. Antibiotic resistance is widespread: more than half of infections are resistant to macrolides and fluoroquinolone resistance is increasing. Resistance-guided therapy is recommended for symptomatic patients, involving initial treatment with doxycycline to reduce organism load followed by azithromycin for macrolide-sensitive infections or moxifloxacin for macrolide-resistant infections. Neither screening nor tests of cure are recommended in asymptomatic persons.

Prevalence of Mycoplasma genitalium infection among HIV PrEP users: a systematic review and meta-analysis

OBJECTIVES

To summarise the prevalence of Mycoplasma genitalium (MG) and antibiotic-resistant MG infection among HIV pre-exposure prophylaxis (PrEP) users.

METHODS

We searched MEDLINE, Embase, Web of Science and Global Index Medicus up to 30 September 2022. We included studies reporting the prevalence of MG and/or antibiotic-resistant MG infection among PrEP users. Two reviewers independently searched for studies and extracted data. A systematic review with random-effects meta-analysis was performed to quantitatively summarise the results of included studies. The critical appraisal of included studies was conducted with the Joanna Briggs Institute checklist for prevalence studies and the quality of evidence was assessed with Grading of Recommendations Assessment, Development and Evaluation (GRADE).

RESULTS

A total of 15 studies were included in the systematic review, with 2341 individuals taking PrEP. Studies were conducted in high-income level countries between 2014 and 2019. Median age of participants varied from 23.5 to 40 years. The majority were men (85%) and among them, 93% were men who have sex with men. To identify MG, urine samples were analysed in 14 studies, rectal or anal swabs in 12 studies, oral or pharyngeal swabs in 9 studies, and urethral or vaginal in 3 studies. The pooled point prevalence of MG among PrEP users was 16.7% (95% CI 13.6% to 20.3%; 95% prediction interval (95% PI) 8.2% to 31.1%). The pooled point prevalence of macrolide-resistant infections was 82.6% (95% CI 70.1% to 90.6%; 95% PI 4.7% to 99.8%) and the prevalence of fluoroquinolone-resistant infections was 14.3% (95% CI 1.8% to 42.8%). Individuals taking PrEP have a higher chance of being infected with MG compared with those not taking PrEP (OR 2.30; 95% CI 1.6 to 3.4). The quality of evidence was very low to moderate.

CONCLUSION

We observed a high prevalence of MG and its macrolide resistance among PrEP users, highlighting the need to reinforce prevention strategies against sexually transmitted infections in this population.

PROSPERO REGISTRATION NUMBER

CRD42022310597.

Low prevalence of macrolide resistance in Mycoplasma genitalium infections in a cohort of pregnant women living with human immunodeficiency virus

OBJECTIVE

Macrolide resistance in Mycoplasma genitalium (M. genitalium) is increasing as a result of the widespread use of azithromycin in the treatment of sexually transmitted infections (STIs). To date, there are few published studies on macrolide resistance patterns in South African pregnant women. This study now contributes to the growing body of knowledge.

METHODS

This study included 385 pregnant women living with HIV. Vaginal swabs were collected from consenting pregnant women and used for the detection of M. genitalium using the TaqMan assay. Macrolide resistance-associated mutations in the 23S rRNA gene were determined for all samples that tested positive for M. genitalium using the Allplex^TM MG & AziR assay (Seegene) which allows for the simultaneous detection and identification of M. genitalium and six mutations (A2058C, A2058G, A2058T, A2059C, A2059G and A2059T) responsible for azithromycin resistance. The correlation between the TaqMan assay and Allplex^TM MG & AziR assay (Seegene) for the detection of M. genitalium was also performed in a subset of 121 samples.

RESULTS

Of the 385 samples tested in this study, 14 samples were positive for M. genitalium estimating a prevalence of 3.6%. The same 14 samples also tested positive on the Allplex^TM assay indicating a good correlation between the TaqMan Assay and the Allplex^TM. Of the 14 positive samples, one sample carried a mutation at position A2059G denoting macrolide resistance in this pathogen. Mutations in the other regions of the 23S rRNA were not detected. All assay controls used in the mutation scanning produced the desired results showing the validity of the assay.

CONCLUSION

In this study, macrolide resistance in M. genitalium was detected. Despite the low prevalence of resistance determinants ongoing antimicrobial resistance surveillance is vital considering that azithromycin is used in the syndromic management for the treatment of vaginal discharge syndrome.

Retrospective Analysis of Ugandan Men with Urethritis Reveals Mycoplasma genitalium and Associated Macrolide Resistance

The rising rates of antimicrobial resistance (AMR) in Mycoplasma genitalium globally and the association of this sexually transmitted infection (STI) with cervicitis, urethritis, and HIV are potentially of great public health concern. Data on the epidemiology of M. genitalium in men in sub-Saharan Africa are limited. We sought to determine the prevalence of M. genitalium and macrolide resistance in men with urethritis in Kampala, Uganda. Self-collected penile-meatal swabs and/or urine samples from men with symptomatic urethritis (n = 250) were retrospectively analyzed for the presence of M. genitalium and macrolide resistance markers with the Aptima M. genitalium and ResistancePlus M. genitalium assays. Additionally, demographic and STI coinfection data were used to investigate associations with M. genitalium infection. M. genitalium was detected in 12.8% (32/250) of individuals; 40.6% (n = 13) had M. genitalium monoinfection. Mutations associated with macrolide resistance were detected in 10.7% (3/28) of participants. Coinfection with Neisseria gonorrhoeae was common (41.0%), but M. genitalium was more prevalent in participants without N. gonorrhoeae coinfection (P = 0.001). M. genitalium is common in Ugandan men with urethritis both as a monoinfection and as a coinfection with other curable STIs. Macrolide resistance was present and warrants further research on treatment outcomes and the association between untreated M. genitalium and subsequent morbidity. IMPORTANCE Mycoplasma genitalium is a common sexually transmitted infection associated with urethritis in men. Little is known about M. genitalium infection in men with urethritis in Uganda. We report that 12% of participants in this study were positive for M. genitalium and that resistance to azithromycin, a macrolide antibiotic, is present. Furthermore, we show that either self-collected penile-meatal swabs or urine can be used for detection of M. genitalium.

Novel strategies for prevention and treatment of antimicrobial resistance in sexually-transmitted infections

PURPOSE OF REVIEW

Antimicrobial resistance in sexually acquired infection (STI) pathogens is an important global public health threat. There is an urgent need for novel STI treatment and prevention strategies to tackle the rising incidence of STIs in high-income settings and the static progress in low- and middle-income settings over the past decade. The purpose of this review was to describe the research outlining the emergence of resistance in common STI pathogens and new strategies for their treatment and prevention.

RECENT FINDINGS

Rates of STIs have dramatically increased over the past decade. Further, antimicrobial resistance to first-line agents among key STI pathogens continues to emerge globally. Recent findings demonstrate promising results regarding the efficacy of novel antimicrobial treatment strategies for these pathogens, including several new, repurposed and unique combinations of antimicrobials. In addition, a number of new biomedical prevention strategies, such as antibacterial mouthwash and doxycycline chemoprophylaxis, are being investigated as novel prevention strategies for bacterial STIs.

SUMMARY

Significant progress has been made in the development of novel antimicrobials for the treatment of antimicrobial-resistant sexually acquired pathogens. However, due to the rapid development of resistance to antimicrobials demonstrated by these pathogens in the past, further research and development of effective prevention strategies should be prioritized.

Antibiotic Resistance and Genotypes of Mycoplasma genitalium during a Resistance-Guided Treatment Regime in a German University Hospital

The treatment of infections from the sexually transmitted pathogen Mycoplasma genitalium is hampered by the rapidly increasing resistance to the recommended first- (macrolides) and second-line antibiotics (quinolones). Thus, resistance-guided therapy (RGT) is key for its successful eradication but the efficiency of this approach can be influenced by re-infections and treatment failures. The typing of strains is helpful to distinguish between ongoing colonization, re-infection or the development of resistance. In the present study, mgpB and MG_309 types as well as mutations associated with macrolide, quinolone and tetracycline resistance of strains in M. genitalium-positive samples accumulated in the years 2019 and 2020 at a university hospital were analyzed. Fifty-eight positive first and sixteen positive follow-up samples from patients (96.6% male, 84.5% men who have sex with men, 74.1% HIV-positive) were included. Twenty-three mgpB types (seven new types), nine MG_309 types and thirty-four mgpB/MG_309 types were identified. The prevalence of mutations associated with macrolide, quinolone and tetracycline resistance was 56.9%, 10.3% and 6.8%, respectively. Despite the fact that many asymptomatic patients were not treated and tests of cure were impossible in different cases, the preliminary rate of successful eradication (93.3%) in this study is promising for the continuation of the RGT strategy.