Prevalence of Mycoplasma genitalium Infection and Macrolide and Fluoroquinolone Resistance Mutations Among US Air Force Service Members With HIV, 2016-2020

Background

Mycoplasma genitalium (MG) infection is a public health concern due to antimicrobial resistance (AMR). Data are limited on repeat MG infection and AMR among US Air Force service members with HIV.

Methods

US Air Force service members seeking HIV care were screened for MG infection during the surveillance period (16 May 2016-16 March 2020). Baseline and repeat MG prevalence rates were estimated. An extended Cox proportional hazards regression model evaluated characteristics associated with repeat MG infection. MG-positive rectal samples were tested for macrolide or fluoroquinolone resistance.

Results

Among 299 male patients from a total of 308 patients followed during the surveillance period, baseline prevalence of MG infection was 19.7% (n = 59); among the 101 patients who screened positive for MG at any time during the surveillance period, repeat MG was 35% (n = 36). Characteristics independently associated with increased risk of repeat infection were sexually transmitted infection history vs none (adjusted hazard ratio [aHR], 2.33; 95% CI, 1.26-4.31), a sexually transmitted infection coinfection vs no positive test result in the medical records (aHR, 5.13; 95% CI, 2.78-9.49), and a new HIV diagnosis (<1 vs ≥1 year; aHR, 2.63; 95% CI, 1.45-3.73). AMR in MG-positive rectal specimens was 88% (43/49) indicating macrolide resistance, 18% (10/56) quinolone resistance, and 18% (10/56) both.

Conclusions

Macrolide and fluoroquinolone resistance mutations were common. Testing for co-occurring MG infection and AMR mutations may be warranted in guiding treatment for sexually transmitted infections such as chlamydia or gonorrhea detected at HIV diagnosis.

Sexually Transmitted Infections in the Emergency Department

As the United States faces a worsening epidemic of sexually transmitted infections (STIs), emergency departments (EDs) play a critical role in identifying and treating these infections. The growing health inequities in the distribution and disproportionate impact of STIs add to the urgency of providing high-quality sexual health care through the ED. Changes in population health are reflected in the new Centers for Disease Control recommendations on screening, diagnostic testing, and treatment of STIs. This review covers common, as well as and less common or emerging STIs, and discusses the state-of-the-art guidance on testing paradigms, extragenital sampling, and antimicrobial treatment and prevention of STIs.

Mycoplasma genitalium: Key Information for the Primary Care Clinician

Mycoplasma genitalium (MG) is an emerging sexually transmitted infection, which appears to be a cause of urethritis and cervicitis and has been associated with pelvic inflammatory disease (PID), epididymitis, proctitis, infertility, complications during pregnancy, and human immunodeficiency virus (HIV) transmission. Three Food and Drug Administration (FDA) approved tests are available. Testing should be focused to avoid inappropriate antibiotic use. The Center of Disease Control and Prevention (CDC) guidelines recommend testing for persistent male urethritis, cervicitis, and proctitis and state that testing should be considered in cases of PID. Testing is also recommended for sexual contacts of patients with MG. Testing is not recommended in asymptomatic patients, including pregnant patients, who do not have a history of MG exposure. Although resistance-guided therapy is recommended, there are currently no FDA approved tests for MG macrolide resistance, and tests are not widely available in the United States. The CDC recommends 2-step treatment with doxycycline followed by azithromycin or moxifloxacin. Moxifloxacin is recommended if resistance testing is unavailable or testing demonstrates macrolide resistance..

Clinical Presentations and Treatment Outcomes of Mycoplasma genitalium Infections at a Large New York City Health Care System

BACKGROUND

Mycoplasma genitalium (MG) is an emerging sexually transmitted infection. Treatment of MG is complicated by increasing resistance to primary treatment regimens, including macrolides and fluoroquinolones. Understanding the various clinical presentations and relative effectiveness of treatments for MG is crucial to optimizing care.

METHODS

Patients with a positive MG nucleic acid amplification test between July 1, 2019, and June 30, 2021, at a large health system in New York City were included in a retrospective cohort. Demographics, clinical presentations, coinfections, treatment, and follow-up microbiologic tests were obtained from the electronic medical record. Associations with microbiologic cure were evaluated in bivariate and multivariable logistic regression models.

RESULTS

Five hundred two unique patients had a positive MG nucleic acid amplification test result during the study period. Male individuals presented predominantly with urethritis (117 of 187 [63%]) and female individuals with vaginal symptoms (142 of 315 [45%]). Among patients with follow-up testing who received a single antibiotic at the time of treatment, 43% (90 of 210) had persistent infection and 57% (120 of 210) had microbiologic cure. Eighty-two percent of patients treated with moxifloxacin had microbiologic cure compared with 41% of patients receiving azithromycin regimens ( P < 0.001). In multivariable analysis, treatment with moxifloxacin was associated with 4 times the odds of microbiologic cure relative to low-dose azithromycin (adjusted odds ratio [aOR], 4.18; 95% confidence interval, 1.73-10.13; P < 0.01).

CONCLUSIONS

Clinical presentations of MG vary, with urethritis or vaginal symptoms in most cases. Among patients who received a single antibiotic, only treatment with moxifloxacin was significantly associated with microbiologic cure relative to low-dose azithromycin.

A multicenter retrospective electronic health record database evaluation of subjects with Mycoplasma genitalium

BACKGROUND

Mycoplasma genitalium is a sexually transmitted infection (STI) increasing in prevalence. The recent availability of nucleic acid amplification tests (NAATs) has led to updated diagnostic and treatment guidelines. As medication therapy experts, pharmacists can facilitate appropriate antimicrobial selection and stewardship and optimize best patient-care practices in the setting of M. genitalium infection.

OBJECTIVE

This study aimed to evaluate patient demographics, therapeutic approaches, and complications of patients with laboratory evidence of M. genitalium hypothesizing that younger adolescent females are affected by this organism, receive suboptimal treatment, and have more complications than adults.

METHODS

This was a retrospective cohort study using TriNetX multicenter electronic health record data of subjects aged 12 years and older with evidence of M. genitalium DNA detected via NAATs. The cohort was divided into 2 age groups: adolescents (12-21 years) and adults (older than 21 years). We evaluated age, sex, race, ethnicity, diagnostic codes, and medication codes.

RESULTS

Our study included 1126 subjects (192 adolescents [17.1%] and 934 adults [82.9%]) who tested positive for M. genitalium. Subjects in the adolescent group had higher odds of being women (2.52 [1.80, 3.54], P < 0.001), having inflammatory diseases of female pelvic organs diagnostic codes (1.51 [1.06, 2.16], P = 0.025), increased odds of azithromycin prescription (1.70 [1.17, 2.48], P = 0.005), and decreased odds of moxifloxacin prescription (0.41 [0.26, 0.64], P < 0.001).

CONCLUSIONS

Our study revealed a higher prevalence of M. genitalium infection in adults and adolescents with increased odds of receiving azithromycin and decreased odds of receiving moxifloxacin. Both age groups had decreased odds of receiving doxycycline compared with azithromycin despite guidelines recommending initial empirical antibiotic treatment with doxycycline and growing macrolide resistance. Suboptimal treatment of this infection may lead to lifelong complications. Pharmacists may provide crucial guidance and education to both patients and health care providers regarding appropriate treatment for M. genitalium.

2023 Korean sexually transmitted infections treatment guidelines for Mycoplasma genitalium by KAUTII

The Korean Association of Urogenital Tract Infection and Inflammation and the Korea Disease Control and Prevention Agency updated the Korean sexually transmitted infections (STIs) guidelines to respond to the changing epidemiologic trends, evolving scientific evidence, and advances in laboratory diagnostics and research. The main recommendations in the Mycoplasma genitalium infection parts of the Korean STIs guidelines 2023 revision are as follows: 1) For initial treatment: azithromycin 500 mg orally in a single dose, then 250 mg once daily for 4 days. 2) In case of treatment failure or recurrence, a macrolide susceptibility/resistance test is required, when susceptibility/resistance test is not feasible, doxycycline or minocycline 100 mg orally twice daily for 7 days, followed by azithromycin 1 g orally on the first day, then azithromycin 500 mg orally once daily for 3 days and then a test-of-cure should be considered 3 weeks after completion of therapy. 3) In case of macrolide sensitivity, doxycycline or minocycline 100 mg orally twice daily for 7 days, followed by azithromycin 1 g orally initial dose, then azithromycin 500 mg orally once daily for 3 days. 4) In case of macrolide resistance, doxycycline or minocycline 100 mg orally twice daily for 7 days, followed by moxifloxacin 400 mg orally once daily for 7 days. In the Korean STIs guideline 2023, macrolide resistance-guided antimicrobial therapy was emphasized due to the increased prevalence of macrolide resistance worldwide. Therefore, in case of treatment failure or recurrence, a macrolide susceptibility/resistance test is required.

Changes in prevalence of Mycoplasma genitalium macrolide and fluoroquinolone resistance: notes from a 13-year retrospective survey in Dalarna County, Sweden

OBJECTIVE

Macrolide and fluoroquinolone resistance in Mycoplasma genitalium (MG) is of emerging global concern. Compared with neighbouring countries such as Denmark, Sweden has had lower rates of macrolide resistance while fluoroquinolone resistance rates are less well documented. This study retrospectively examined macrolide, fluoroquinolone and multidrug resistance rates from Dalarna County, Sweden over a 13-year period.

METHODS

MG-positive samples from 2006 to 2018 from patients examined at the Department of Venereology, Central Hospital, Falun, Sweden were tested by sequencing for macrolide resistance mutations (MRM) and fluoroquinolone resistance-associated mutations (QRAM) in the parC and gyrA subunit regions. A subset of these samples from 2006 to 2011 have been reported on previously, although only for MRM.

RESULTS

Of 874 samples, 98 (11.2%, 95% CI 9.1% to 13.6%) had mutations associated with resistance to macrolides and 19 of 828 (2.3%, 95% CI 8.9% to 23.1%) to quinolones. Mutations associated with resistance to both drugs were detected in 5 of 828 (0.6%, 95% CI 0.1% to 1.4%) samples overall. A significant positive linear trend (p=0.004) for an increase in the rate of macrolide resistance was observed (from 0% in 2006 to 31% in 2018) while the increase in QRAM from 0% in 2006 to 12.3% in 2018 was not statistically significant.

CONCLUSIONS

Despite a decrease in macrolide and fluoroquinolone consumption in Sweden, there was an overall increase in MG macrolide, fluoroquinolone and dual resistance from 2006 to 2018, although the difference in fluoroquinolone resistance rates was not statistically significant. In order to maintain comparably low resistance rates, resistance-guided therapy for MG infections will be crucial.

Treatment of bacterial sexually transmitted infections in Europe: gonorrhoea, Mycoplasma genitalium, and syphilis

This review explores the therapeutic challenges of sexually transmitted infections (STI) in Europe, which include increasing antimicrobial resistance and limited progress in drug discovery. We primarily focus on gonorrhoea, Mycoplasma genitalium, and syphilis infections. For gonorrhoea with escalating resistance rates we explore the possibility of combining ceftriaxone with another antibiotic or using alternative antibiotics to mitigate resistance emergence, and we provide insights on the ongoing evaluation of new antimicrobials, like gepotidacin and zoliflodacin. In the case of M. genitalium, which exhibits high resistance rates to first and second-line treatments, we emphasize the importance of resistance-guided therapy in regions with elevated resistance levels, and highlight the limited alternative options, such as pristinamycin and minocycline. Furthermore, we address the challenges posed by syphilis, where the primary treatment consists of penicillin or doxycycline, with challenges arising in neurosyphilis, allergy, pregnancy, and supply shortages and discuss the ongoing evaluation of alternative antimicrobials (e.g., ceftriaxone, cefixime, linezolid). Our findings identify priority actions and provide concrete solutions for long-term effective management of STIs and antimicrobial resistance mitigation.

Emerging Antimicrobial Resistance

The burden of emerging antimicrobial resistance (AMR) in the United States is significant and even greater worldwide. Mitigation efforts have decreased the incidence and deaths from antimicrobial-resistant organisms in the United States. Yet more than 2.8 million antimicrobial-resistant infections occur every year and more than 35,000 patients die as a result. Infection prevention and control, data tracking, antimicrobial stewardship, vaccines, therapeutics, diagnostics, and sanitation are all required to decrease AMR threats. In 2019, in the second version of the Centers for Disease Control and Prevention (CDC) report on antibiotic-resistant threats, the agency categorized AMR threats as urgent, serious, concerning, or to be watched. This review will discuss the following aspects of each bacterium in the CDC report: estimated numbers of cases and deaths, identify the better known and impactful mechanisms of resistance, diagnostic testing and its limitations, and current and possible future therapies. This review also presents anatomical pathology case examples that highlight the altered morphology of antibiotic partially treated bacteria in tissues.

Cost-effectiveness of testing for Mycoplasma genitalium among men who have sex with men in Australia

OBJECTIVES

Mycoplasma genitalium (MG) disproportionately affects men who have sex with men (MSM). We determined the cost-effectiveness of different testing strategies for MG in MSM, taking a healthcare provider perspective.

METHODS

We used inputs from a dynamic transmission model of MG among MSM living in Australia in a decision tree model to evaluate the impact of four testing scenarios on MG incidence: (1) no one tested; (2) symptomatic MSM; (3) symptomatic and high-risk asymptomatic MSM; (4) all MSM. We calculated the incremental cost-effectiveness ratios (ICERs) using a willingness-to-pay threshold of $A30 000 per quality-adjusted life year (QALY) gained. We explored the impact of adding an antimicrobial resistance (AMR) tax (ie, additional cost per antibiotic consumed) to identify the threshold, whereby any testing for MG is no longer cost-effective.

RESULTS

Testing only symptomatic MSM is the most cost-effective (ICER $3677 per QALY gained) approach. Offering testing to all MSM is dominated (ie, higher costs and lower QALYs gained compared with other strategies). When the AMR tax per antibiotic given was above $150, any testing for MG was no longer cost-effective.

CONCLUSION

Testing only symptomatic MSM is the most cost-effective option, even when the potential costs associated with AMR are accounted for (up to $150 additional cost per antibiotic given). For pathogens like MG, where there are anticipated future costs related to AMR, we recommend models that test the impact of incorporating an AMR tax as they can change the results and conclusions of cost-effectiveness studies.

Latest Advances in Laboratory Detection of Mycoplasma genitalium

Mycoplasma genitalium is an important sexually transmitted pathogen affecting both men and women. Its extremely slow growth in vitro and very demanding culture requirements necessitate the use of molecular-based diagnostic tests for its detection in clinical specimens. The recent availability of U.S. Food and Drug Administration (FDA)-cleared commercial molecular-based assays has enabled diagnostic testing to become more widely available in the United States and no longer limited to specialized reference laboratories. Advances in the knowledge of the epidemiology and clinical significance of M. genitalium as a human pathogen made possible by the availability of molecular-based testing have led to updated guidelines for diagnostic testing and treatment that have been published in various countries. This review summarizes the importance of M. genitalium as an agent of human disease, explains the necessity of obtaining a microbiological diagnosis, describes currently available diagnostic methods, and discusses how the emergence of antimicrobial resistance has complicated treatment alternatives and influenced the development of diagnostic tests for resistance detection, with an emphasis on developments over the past few years.

Genetic Determinants of Macrolide and Fluoroquinolone Resistance in Mycoplasma genitalium and Their Prevalence in Moscow, Russia

Macrolide (MLR) and fluoroquinolone (FQR) resistance in Mycoplasma genitalium (MG) has recently become a major problem worldwide. The available data on the prevalence of MLR and FQR in MG in Russia are limited. In this study, we aimed to evaluate the prevalence and pattern of mutations in 213 MG-positive urogenital swabs from patients in Moscow between March 2021 and March 2022. MLR- and FQR-associated mutations were searched in 23S rRNA as well as in the parC and gyrA genes using Sanger sequencing. The prevalence of MLR was 55/213 (26%), with A2059G and A2058G substitutions being the two most common variants (36/55, 65%, and 19/55, 35%, respectively). FQR detection showed 17% (37/213); two major variants were D84N (20/37, 54%) and S80I (12/37, 32.4%) and three minor variants were S80N (3/37, 8.1%), D84G (1/37, 2.7%), and D84Y (1/37, 2.7%). Fifteen of the fifty-five MLR cases (27%) simultaneously harbored FQR. This study revealed the high frequency of MLR and FQR. We conclude that the improvement of patient examination algorithms and therapeutic approaches should be combined with the routine monitoring of antibiotic resistance based on the sensitivity profiles presented. Such a complex approach will be essential for restraining the development of treatment resistance in MG.

Weighing Potential Benefits and Harms of Mycoplasma genitalium Testing and Treatment Approaches

This systematic review demonstrates increasing antimicrobial resistance and incomplete understanding of the bacterium’s natural history.

Since Mycoplasma genitalium was identified 40 years ago, much of the epidemiology has been described, diagnostic tests have been developed and approved, and recommended treatment approaches have been identified. However, the natural history remains incompletely understood, and antimicrobial resistance has rapidly increased. This review summarizes evidence published since the US Centers for Disease Control and Prevention 2015 Sexually Transmitted Diseases Treatment Guidelines. Data on sequelae remain insufficient, macrolide resistance is common, and fluoroquinolone resistance is increasing. Potential benefits of testing and treatment include resolving symptoms, interrupting transmission, and preventing sequelae. Potential harms include cost, patient anxiety, and increasing antimicrobial resistance.

Azithromycin treatment failure and macrolide resistance in Mycoplasma genitalium infections in Sofia, Bulgaria

INTRODUCTION

Mycoplasmagenitalium is an established cause of sexually transmitted infections in men and women. Current guidelines recommend azithromycin and moxifloxacin as first- and second-line treatment, respectively. However, azithromycin treatment failure has been increasingly reported. The aim of this study was to determine the efficacy of azithromycin and alternative antibiotic regimens in a prospective cohort of M.genitalium-positive patients, and macrolide resistance mutations associated with azithromycin failure.

Key Factors in Effective Patient-Tailored Dosing of Fluoroquinolones in Urological Infections: Interindividual Pharmacokinetic and Pharmacodynamic Variability

Fluoroquinolones (FQs) are a critical group of antimicrobials prescribed in urological infections as they have a broad antimicrobial spectrum of activity and a favorable tissue penetration at the site of infection. However, their clinical practice is not problem-free of treatment failure, risk of emergence of resistance, and rare but important adverse effects. Due to their critical role in clinical improvement, understanding the dose-response relation is necessary to optimize the effectiveness of FQs therapy, as it is essential to select the right antibiotic at the right dose for the right duration in urological infections. The aim of this study was to review the published literature about inter-individual variability in pharmacological processes that can be responsible for the clinical response after empiric dose for the most commonly prescribed urological FQs: ciprofloxacin, levofloxacin, and moxifloxacin. Interindividual pharmacokinetic (PK) variability, particularly in elimination, may contribute to treatment failure. Clearance related to creatinine clearance should be specifically considered for ciprofloxacin and levofloxacin. Likewise, today, undesired interregional variability in FQs antimicrobial activity against certain microorganisms exists. FQs pharmacology, patient-specific characteristics, and the identity of the local infecting organism are key factors in determining clinical outcomes in FQs use.

Detection and Prevalence of Macrolide and Fluoroquinolone Resistance in Mycoplasma genitalium in Badalona, Spain

Macrolide and fluoroquinolone resistance (MLr/FQr) in Mycoplasma genitalium (MG) infections is concerning worldwide. Current guidelines recommend performing MLr detection in MG-positive cases to adjust antimicrobial therapy. We aimed to evaluate the usefulness of PCR followed by pyrosequencing for MLr detection in comparison with a one-step commercial assay and to assess the prevalence of MLr and FQr in Badalona, Spain. A total of 415 MG-positive samples by Allplex STI-7 (Seegene) were analyzed for MLr detection by pyrosequencing. From those, 179 samples were further analyzed for MG and MLr by ResistancePlus^® MG kit (SpeeDx) and 100 of them also for fluoroquinolone resistance (FQr) by sequencing the parC gene. Regarding MG detection, Allplex and Resistance Plus^® showed an overall agreement of 87%, but this value rose to 95.4% if we compare them for MLr detection. Prevalence of MLr was 23.1% in Badalona, but this rate increased to 73.7% in the HIV-positive patients cohort. FQr detection showed 3% of resistant strains. Pyrosequencing is a convenient and cheap technique for MLr detection, but one-step tools should be considered in high-throughput laboratories. Despite the fact that MLr remained moderate and FQr was low in our study, simultaneous MG and MLr detection would improve patient’s management applying resistance-guided treatment strategies.

A Systematic Review and Meta-Analysis of Efficacy and Safety of Azithromycin Versus Moxifloxacin for the Initial Treatment of Mycoplasma genitalium Infection

Mycoplasma genitalium is recognized as a remarkable pathogen since azithromycin-resistant strains and treatment failure have been increasingly reported. Nevertheless, international guidelines still recommend azithromycin as a first-line treatment and moxifloxacin as a second-line treatment. We performed a systematic review and meta-analysis to validate the efficacy and safety of both drugs in the initial treatment of M. genitalium. We systematically searched the EMBASE, PubMed, Scopus, Ichushi, and CINAHL databases up to December 2021. We defined efficacy as clinical and microbiologic cure, and safety as persistent diarrhea. Overall, four studies met the inclusion criteria: one showed clinical cure (azithromycin treatment, n = 32; moxifloxacin treatment, n = 6), four showed microbiologic cure (n = 516; n = 99), and one showed safety (n = 63; n = 84). Moxifloxacin improved the microbiologic cure rate compared with azithromycin (odds ratio [OR] 2.79, 95% confidence interval [CI], 1.06–7.35). Clinical cure and safety did not show a significant difference between azithromycin and moxifloxacin treatments (OR 4.51, 95% CI 0.23–88.3; OR 0.63, 95% CI 0.21–1.83). Our meta-analysis showed that moxifloxacin was more effective than azithromycin at eradicating M. genitalium infections and supports its preferential use as a first-line treatment.

Evaluation of treatment with two weeks of doxycycline on macrolide-resistant strains of Mycoplasma genitalium: a retrospective observational study

BACKGROUND

Increasing macrolide resistance makes treatment of Mycoplasma genitalium infections challenging. The second-line treatment is moxifloxacin, an antibiotic drug best avoided due to the potential of severe side effects and interactions. This study evaluates the effects of treatment with doxycycline 100 mg twice daily for 2 weeks as an alternative to moxifloxacin.

METHODS

This retrospective observational study examined the medical records of patients testing positive for macrolide resistant Mycoplasma genitalium from January 1st, 2016 to September 1st, 2019 in Trondheim, Norway. Information regarding symptoms as well as clinical and microbiological cure was collected.

RESULTS

263 infections from 259 patients (161 females/98 males) were examined. 155 (58.9%) had a negative test of cure following treatment. 34.7% of symptomatic patients not achieving microbiological cure experienced symptom relief or clearance. There was no statistical difference between bacterial loads in symptomatic versus asymptomatic patients. The mean difference was 1.6 × 105 copies/ml (95% CI - 1.4 × 105-4.8 × 105, p = 0.30) for women and 1.4 × 106 copies/ml (95% CI -4.0 × 105-3.2 × 106, p = 0.12) for men.

CONCLUSIONS

The cure rate of doxycycline in this study is higher than previously reported. This adds support to doxycycline's role in treatment before initiating treatment with less favorable drugs such as moxifloxacin.

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.

Prevalence of Mycoplasma genitalium fluoroquinolone-resistance markers, and dual-class-resistance markers, in asymptomatic men who have sex with men

Introduction. Failure of fluoroquinolones, the principal treatment option for macrolide-resistant Mycoplasma genitalium infections, has recently emerged. This is of particular concern for men who have sex with men (MSM), who have high proportions of macrolide-resistant M. genitalium infections. Treatment failure with moxifloxacin is likely the result of single nucleotide polymorphisms (SNPs) in parC, whilst concurrent gyrA mutations may play a role.Gap Statement. The levels of fluoroquinolone resistance and dual-class (i.e. macrolide and fluoroquinolone) resistance in M. genitalium among asymptomatic MSM is unknown.Aim. To (i) determine the proportion of fluoroquinolone resistance and dual-class resistance in M. genitalium infections among asymptomatic MSM, (ii) explore any clinical and behavioural associations with fluoroquinolone resistance, and (iii) determine the distribution of antibiotic resistance among M. genitalium mgpB sequence types (STs).Methodology. M. genitalium positive samples (N=94) were obtained from 1001 asymptomatic MSM enrolled in a study at Melbourne Sexual Health Centre (Carlton, Australia) between August 2016 and September 2017. Sanger sequencing was performed to determine the proportion of M. genitalium infections with SNPs in parC that have previously been associated with failure of moxifloxacin (corresponding to amino changes S83I, D83R, D87Y and D87N) and in gyrA (corresponding to amino acid changes M95I, D99N, D99Y and D99G). Associations between clinical/behavioural factors and parC SNPs were examined. Strain typing was performed by sequencing a portion of the mgpB gene.Results. The proportion of MSM with infections harbouring parC and gyrA SNPs was 13.0 % [95 % confidence interval (CI): 6.8-23.2 %] and 4.7 % (95 % CI: 1.1-13.4 %), respectively; dual-class resistance was 13.0 %. No significant clinical/behavioural associations were found. Antibiotic resistance was not restricted to specific mgpB STs.Conclusion. One in eight (13 %) of asymptomatic MSM with M. genitalium had an infection with dual-class-resistance mutations. Typing by mgpB sequence suggested fluoroquinolone resistance is arising from independent mutation events. This study illustrates that asymptomatic MSM may act as a reservoir for antibiotic-resistant M. genitalium.

High Prevalence of Macrolide and Fluoroquinolone Resistance-Mediating Mutations in Mycoplasma genitalium-Positive Urine Specimens From Saskatchewan

BACKGROUND

Mycoplasma genitalium is an emerging, sexually transmitted infection, which is more prevalent than Chlamydia trachomatis in some regions. An increase in antibiotic resistance, that is, azithromycin and moxifloxacin, recommended for treating M. genitalium infections has been noted. This is the first detailed report on the prevalence of M. genitalium and its antimicrobial resistance in Saskatchewan, Canada.

METHODS

Aptima urine specimens (n = 1977), collected for the diagnosis of C. trachomatis/Neisseria gonorrhoeae, were tested for M. genitalium using the Aptima M. genitalium assay (MG-TMA). Antimicrobial resistance was ascertained using polymerase chain reaction and DNA sequencing of 23S rRNA (azithromycin) and parC (moxifloxacin) from Aptima M. genitalium assay-positive specimens; mutations predictive of resistance were noted.

RESULTS

The prevalence of M. genitalium was 9.6% (189/1977). Predicted resistance to azithromycin (substitutions at positions 2058/2059 in 23S rRNA) was observed in 63.6% (70/110) of the specimens tested, whereas resistance to moxifloxacin (S83I in ParC) was observed in 10.6% (9/85) of the specimens. Mutations in both 23S rRNA and ParC were observed in 2.12% (4/189) of the specimens. Women aged 20 to 24 years had the highest prevalence (18.3%, P < 0.001), and in females, M. genitalium was significantly associated with C. trachomatis or N. gonorrhoeae/C. trachomatis (P < 0.001) coinfection. The prevalence of M. genitalium (9.6%) in the province of Saskatchewan was higher than that of the other 2 bacterial sexually transmitted infections (N. gonorrhoeae (3.09%) and C. trachomatis (6.85%).

CONCLUSIONS

The prevalence of M. genitalium (9.6%) and associated resistance to azithromycin (63.6%) in Saskatchewan high, suggesting that empiric azithromycin therapy may not be adequate for treating M. genitalium infections.

Sexually Transmitted Infections Treatment Guidelines, 2021

These guidelines for the treatment of persons who have or are at risk for sexually transmitted infections (STIs) were updated by CDC after consultation with professionals knowledgeable in the field of STIs who met in Atlanta, Georgia, June 11–14, 2019. The information in this report updates the 2015 guidelines. These guidelines discuss 1) updated recommendations for treatment of Neisseria gonorrhoeae, Chlamydia trachomatis, and Trichomonas vaginalis; 2) addition of metronidazole to the recommended treatment regimen for pelvic inflammatory disease; 3) alternative treatment options for bacterial vaginosis; 4) management of Mycoplasma genitalium; 5) human papillomavirus vaccine recommendations and counseling messages; 6) expanded risk factors for syphilis testing among pregnant women; 7) one-time testing for hepatitis C infection; 8) evaluation of men who have sex with men after sexual assault; and 9) two-step testing for serologic diagnosis of genital herpes simplex virus. Physicians and other health care providers can use these guidelines to assist in prevention and treatment of STIs.

High prevalence and resistance rates of Mycoplasma genitalium among patients visiting two sexually transmitted infection clinics in the Netherlands

Mycoplasma genitalium is a well-known cause of urethritis in men and has been associated with cervicitis, pelvic inflammatory disease, and adverse obstetric outcomes in women. In this cross-sectional study, we determined the current prevalence of M. genitalium infection and the rate of macrolide resistance in M. genitalium isolates, in patients visiting two large Dutch sexually transmitted infection (STI) clinics, to evaluate whether the recommendations in Dutch guidelines should be revised. In addition, risk factors for M. genitalium were identified. In total, 3225 patients were included. M. genitalium prevalence rates were 13.8% for all patients; 20.1% for men who have sex with men, 8.2% for men who have sex with women, and 12.6% for women. Macrolide resistance-associated mutations were detected in 66% of the patients infected with M. genitalium. Age, educational level, country of origin, number of sexual partners, HIV-positivity, infection with Neisseria gonorrhoeae, and urethral symptoms in men were independently associated with M. genitalium infection. In conclusion, we found very high prevalence rates and macrolide resistance rates of M. genitalium in patients visiting STI clinics.

Impact of screening on the prevalence and incidence of Mycoplasma genitalium and its macrolide resistance in men who have sex with men living in Australia: A mathematical model

BACKGROUND

Mycoplasma genitalium (MG) causes a sexually transmitted infection (STI) with a rising rate of antimicrobial resistance. Currently, guidelines do not recommend screening asymptomatic men who have sex with men (MSM). We developed a mathematical model of MG transmission to examine the impact of various screening strategies on the incidence and prevalence of MG among MSM attending a sexual health clinic.

METHODS

A compartmental mathematical model of MG transmission among MSM was constructed and calibrated using data from the Melbourne Sexual Health center, where resistance-guided therapy provides high treatment effectiveness (92-95%). The model stratified men by symptom status, sexual risk behaviours and whether or not they had MG with macrolide resistance. We simulated the impact on endemic steady-state MG prevalence and incidence of the following screening scenarios, namely screening: 1) no MSM; 2) only symptomatic MSM (the current recommendation); 3) all symptomatic and high-risk asymptomatic MSM; and 4) all MSM. Our base case analysis assumed a treatment effectiveness of 92-95% using resistance-guided therapy. We also examined the impact of treatment effectiveness (i.e. the proportion of detected MG that were cured) and screening coverage (i.e. testing rate) on MG prevalence.

FINDINGS

The model predicts that the overall endemic MG prevalence is 9.1% (95% CI: 7.9-10.0) in the current situation where screening is only offered to symptomatic MSM (base-case). This would increase to 11·4% (95% confidence intervals (CI): 10.2-13.7) if no MSM are offered screening, but would decrease to 7.3% (95% CI: 5.7-8.4) if all symptomatic and high-risk asymptomatic MSM were offered screening and 6.4% (95% CI: 4.7-7·7) if all MSM were offered screening. Increasing coverage of MSM screening strategies shows a similar effect on decreasing endemic MG incidence. When evaluating the simultaneous impact of treatment effectiveness and screening coverage, we found that offering screening to more MSM may reduce the overall prevalence but leads to a higher proportion of macrolide-resistant MG, particularly when using treatment regimens with lower effectiveness.

INTERPRETATION

Based on the available treatment options, offering screening for MG to other MSM (beyond the currently recommended group of symptomatic MSM) could slightly reduce the prevalence and incidence of MG. However, further increasing screening coverage must be weighed against the impact of lower treatment effectiveness (i.e. when not using resistance-guided therapy), increasing the selection of macrolide resistance, and other negative consequences related to AMR and management (e.g. unnecessary psychological morbidity from infections that do not need treatment).

Macrolide and fluoroquinolone associated mutations in Mycoplasma genitalium in a retrospective study of male and female patients seeking care at a STI Clinic in Guangzhou, China, 2016-2018

Background

Antimicrobial resistance in M. genitalium is a growing clinical problem. We investigated the mutations associated with macrolide and fluoroquinolone resistance, two commonly used medical regimens for treatment in China. Our aim is to analyze the prevalence and diversity of mutations among M. genitalium-positive clinical specimens in Guangzhou, south China.

Methods

A total of 154 stored M. genitalium positive specimens from men and women attending a STI clinic were tested for macrolide and fluoroquinolone mutations. M. genitalium was detected via TaqMan MGB real-time PCR. Mutations associated with macrolide resistance were detected using primers targeting region V of the 23S rRNA gene. Fluoroquinolone resistant mutations were screened via primers targeting topoisomerase IV (parC) and DNA gyrase (gyrA).

Results

98.7% (152/154), 95.5% (147/154) and 90.3% (139/154) of M. genitalium positive samples produced sufficient amplicon for detecting resistance mutations in 23S rRNA, gyrA and parC genes, respectively. 66.4% (101/152), 0.7% (1/147) and 77.7% (108/139) samples manifested mutations in 23S rRNA, gyrA and parC genes, respectively. A2072G (59/101, 58.4%) and S83I (79/108, 73.1%) were highly predominating in 23S rRNA and parC genes, respectively. Two samples had amino acid substitutions in gyrA (M95I and A96T, respectively). Two samples had two amino acid substitutions in parC (S83I + D87Y). 48.6% (67/138) of samples harbored both macrolide and fluoroquinolone resistance-associated mutations. The most common combination of mutations was A2072G (23S rRNA) and S83I (parC) (40/67, 59.7%). One sample had three amino acid changes in 23S rRNA, gyrA and parC genes (A2072G + A96T + S83I).

Conclusions

The high antimicrobial resistance rate of M. genitalium in Guangzhou is a very worrying problem and suggests that antimicrobial resistance testing and the development of new antibiotic regimens are crucially needed.

Mycoplasma genitalium: A Review

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

Recent advances in understanding and combatting Mycoplasma genitalium

Mycoplasma genitalium has emerged over the last 30 years as a sexually transmitted infection (STI). As data have accumulated, our understanding of this pathogen and its role in disease continues to evolve. This in turn creates new challenges and complexities. Questions remain regarding the natural history of M. genitalium, its contribution to disease and long-term sequelae. A decline in cure rates for first-line anti-microbials has been observed. This is likely in part due to high usage of single-dose azithromycin in the sexual health field but also due to the intrinsic ability of M. genitalium to rapidly acquire anti-microbial resistance. Consequently, the term 'the new STI superbug' is not infrequently used by the media to describe this pathogen. Currently available antibiotics have side effects that, though rare, are potentially serious. This leads to inherent questions regarding the benefit of testing for and treating M. genitalium, particularly in asymptomatic individuals or in genital syndromes where the benefit of treatment is not well established. In this review, we summarize the most recent evidence and literature regarding M. genitalium and explore areas of research where disparities exist. We discuss the contribution of M. genitalium to genital syndromes, particularly those where data are conflicting, in order to inform indications for testing and treatment. Avoidance of increasing anti-microbial resistance with astute anti-microbial stewardship is paramount if we are to successfully manage M. genitalium infection. We examine the state of play regarding anti-microbial resistance and how to combat this, including currently available anti-microbials, resistance-guided therapy and novel therapeutic approaches. We aim to provide an overview of the current understanding of M. genitalium and the implications for current clinical practise and suggestions for future research.

Prevalence of mutations associated with resistance to macrolides and fluoroquinolones in Mycoplasma genitalium: a systematic review and meta-analysis

BACKGROUND

Mycoplasma genitalium is now recognised as an important bacterial sexually transmitted infection. We summarised data from studies of mutations associated with macrolide and fluoroquinolone resistance in M genitalium to establish the prevalence of resistance. We also investigated temporal trends in resistance and aimed to establish the association between resistance and geographical location.

METHODS

In this systematic review and meta-analysis, we searched PubMed, Embase, and MEDLINE for studies that included data for the prevalence of mutations associated with macrolide and fluoroquinolone resistance in M genitalium published in any language up to Jan 7, 2019. We defined prevalence as the proportion of M genitalium samples positive for key mutations associated with azithromycin resistance (23S rRNA gene, position 2058 or 2059) or moxifloxacin resistance (S83R, S83I, D87N, or D87Y in parC), or both, among all M genitalium samples that were successfully characterised. We used random-effects meta-analyses to calculate summary estimates of prevalence. Subgroup and meta-regression analyses by WHO region and time period were done. This study was registered with PROSPERO, number CRD42016050370.

RESULTS

Overall, 59 studies from 21 countries met the inclusion criteria for our study: 57 studies of macrolide resistance (8966 samples), 25 of fluoroquinolone resistance (4003 samples), and 22 of dual resistance to macrolides and fluoroquinolones (3280 samples). The summary prevalence of mutations associated with macrolide resistance among M genitalium samples was 35·5% (95% CI 28·8-42·5); prevalence increased from 10·0% (95% CI 2·6-20·1%) before 2010, to 51·4% (40·3-62·4%) in 2016-17 (p<0·0001). Prevalence of mutations associated with macrolide resistance was significantly greater in samples in the WHO Western Pacific and Americas regions than in those from the WHO European region. The overall prevalence of mutations associated with fluoroquinolone resistance in M genitalium samples was 7·7% (95% CI 4·5-11·4%). Prevalence did not change significantly over time, but was significantly higher in the Western Pacific region than in the European region. Overall, the prevalence of both mutations associated with macrolide resistance and those associated with fluoroquinolone resistance among M genitalium samples was 2·8% (1·3-4·7%). The prevalence of dual resistance did not change significantly over time, and did not vary significantly by geographical region.

INTERPRETATION

Global surveillance and measures to optimise the efficacy of treatments-including resistance-guided strategies, new antimicrobials, and antimicrobial combination approaches-are urgently needed to ensure cure in a high proportion of M genitalium infections and to prevent further spread of resistant strains.

FUNDING

Australian National Health and Medical Research Council.

Resolution of Symptoms and Resumption of Sex After Diagnosis of Nongonococcal Urethritis Among Men Who Have Sex With Men

BACKGROUND

Standard counseling at nongonococcal urethritis (NGU) diagnosis includes advice to abstain from sex for at least 7 days and until symptoms resolve.

METHODS

From December 2014 to July 2018, we enrolled men who have sex with men and received azithromycin (1 g) for NGU at the Public Health-Seattle and King County STD Clinic. Over 12 weeks of follow-up, participants reported daily urethral symptoms and sexual activity on web-based diaries. Nongonococcal urethritis was defined as urethral symptoms or visible urethral discharge plus 5 or greater polymorphonuclear leukocytes per high-power field. Time of symptom resolution was defined as the first of 5 consecutive asymptomatic days.

RESULTS

Of 100 participants with NGU and no Chlamydia trachomatis (CT)/Mycoplasma genitalium (MG) coinfection, 36 (36%), 22 (22%), and 42 (42%) had CT-NGU, MG-NGU, and non-CT/non-MG NGU, respectively. Among men with MG-NGU, 94% had a macrolide resistance mutation. For all etiologies, median time to symptom resolution after azithromycin was 7 days (95% confidence interval [CI], 5-9); 37% had symptoms lasting longer than 7 days. For men with CT-NGU, MG-NGU, and non-CT/non-MG NGU, median time to symptom resolution was 4 days (95% CI, 2-6; 16% >7 days), undefined days (95% CI, 7 to undefined; 60% >7 days), and 7 days (95% CI, 5-11; 46% >7 days), respectively. Median time to first sexual activity (any type) was 12 days (95% CI, 11-17); it was 16 days (95% CI, 12-18) to first urethral sexual exposure. Twenty-seven percent did not avoid urethral exposure for the recommended period.

CONCLUSIONS

Counseling at NGU diagnosis should educate patients that symptoms may persist more than 7 days, particularly for non-CT NGU, and emphasize the rationale for the 7-day abstinence period.

Outcomes of Resistance-guided Sequential Treatment of Mycoplasma genitalium Infections: A Prospective Evaluation

Background

Rising macrolide and quinolone resistance in Mycoplasma genitalium necessitate new treatment approaches. We evaluated outcomes of sequential antimicrobial therapy for M. genitalium guided by a macrolide-resistance assay.

Methods

In mid-2016, Melbourne Sexual Health Centre switched from azithromycin to doxycycline (100 mg twice daily for 7 days) for nongonococcal urethritis, cervicitis, and proctitis. Cases were tested for M. genitalium and macrolide-resistance mutations (MRMs) by polymerase chain reaction. Directly after doxycycline, MRM-negative infections received 2.5 g azithromycin (1 g, then 500 mg daily for 3 days), and MRM-positive infections received sitafloxacin (100 mg twice daily for 7 days). Assessment of test of cure and reinfection risk occurred 14-90 days after the second antibiotic.

Results

Of 244 evaluable M. genitalium infections (52 women, 68 heterosexual men, 124 men who have sex with men) diagnosed from 20 June 2016 to 15 May 2017, MRMs were detected in 167 (68.4% [95% confidence interval {CI}, 62.2%-74.2%]). Treatment with doxycycline decreased bacterial load by a mean 2.60 log10 (n = 56; P < .0001). Microbiologic cure occurred in 73 of 77 MRM-negative infections (94.8% [95% CI, 87.2%-98.6%]) and in 154 of 167 MRM-positive infections (92.2% [95% CI, 87.1%-95.8%]). Selection of macrolide resistance occurred in only 2 of 76 (2.6% [95% CI, .3%-9.2%]) macrolide-susceptible infections.

Conclusions

In the context of high levels of antimicrobial resistance, switching from azithromycin to doxycycline for presumptive treatment of M. genitalium, followed by resistance-guided therapy, cured ≥92% of infections, with infrequent selection of macrolide resistance.

Evaluation of the ResistancePlus MG FleXible Assay for Detection of Wild-Type and 23S rRNA-Mutated Mycoplasma genitalium Strains

Antibiotic resistance in Mycoplasma genitalium is rising globally, and resistance-guided diagnostics can facilitate targeted and timely treatment. The ResistancePlus MG FleXible (RPMG Flex) assay for the detection of M. genitalium and macrolide resistance-mediating mutations (MRMM) was evaluated for analytical sensitivity, specificity, reproducibility, and inhibition in the presence of interfering substances by simulating M. genitalium-negative pooled urine and swab matrices with M. genitalium cultures. Furthermore, the clinical sensitivity of the assay was evaluated and compared with a reference real-time PCR assay. The analytical sensitivity of the RPMG Flex assay was 157 genomes/ml for wild-type (WT) and 387 genomes/ml for MRMM strains in both matrices. For clinical specimens, the RPMG assay had an overall sensitivity of 96.1% (95% urine: 10/10 WT, 9/10 MRMM; 96.5% swab: 25/26 WT, 26/29 MRMM) compared to 85.7% for the MgPa/MagNAPure24 assay (95% urine: 19/20; 87% swab: 48/57). Clinical specificity was 100% for urine and 98.5% for swab specimens, respectively. No inhibition due to the presence of any of the tested interfering substances was observed. The RPMG Flex assay was more sensitive than the reference MgPa assay, in particular, for swab specimens. The implementation of this assay may increase ease of use and considerably decrease hands-on time for sample preparation compared to a standard block-based assay. The RPMG Flex assay for the GeneXpert Dx system provides a much-needed platform for the simultaneous detection of MG and MRMM and may thereby facilitate resistance-guided therapy for M. genitalium infections.

Antimicrobial resistance in sexually transmitted infections

RATIONALE FOR REVIEW

International travel facilitates the spread of drug-resistant infections, including sexually transmitted infections (STIs). In 2016, the World Health Organization highlighted the global burden of 'curable' STIs, estimating 376 million new infections of gonorrhoea, chlamydia, syphilis and trichomoniasis annually, with considerable geographic variation in both the burden of disease and prevalence of resistance. Travelers' risk of contracting and transmitting drug-resistant STIs depends in part on their geographic exposure. In this review, we describe the epidemiology of antimicrobial resistance (AMR) and the management of these four common STIs and Mycoplasma genitalium, an increasingly recognized cause of non-gonococcal urethritis.

KEY FINDINGS

Multi-drug and extensively drug resistant gonorrhoea strains have been associated with international spread, particularly in travelers returning from Southeast Asia. Chlamydia is the most common bacterial STI worldwide. Although in vitro resistance has been reported, surveillance data suggest that clinically significant resistance to macrolides and tetracyclines is rare. Macrolide resistance in syphilis is now endemic in much of the world but there is no documented penicillin resistance, which remains first-line therapy. Trichomoniasis is the most common non-viral STI worldwide. Although clinical failure after treatment occurs, resistance to metronidazole is thought to be uncommon. Mycoplasma genitalium exhibits intrinsic resistance to many antibiotics, and the prevalence of resistance to both first- and second-line regimens (macrolides and fluoroquinolones) is increasing worldwide, with limited alternative therapeutic options.

RECOMMENDATIONS

International travelers are at risk for acquiring resistant STIs with limited therapeutic options. Improved diagnostics are urgently needed to improve AMR surveillance and the management of infected patients. As no vaccinations are currently available for these STIs, and pre-exposure prophylaxis is an area of active study with limited data, condom use is critical for prevention. Travel medicine providers should incorporate STI risk reduction counselling, with an emphasis on condom use, into the routine pre-travel consultation.

Prevalence and antibiotic resistance of rectal Mollicutes in HIV-infected men who have sex with men at the University Hospital of Dresden, Germany

BACKGROUND

Rectal sexually transmitted infections (STI) are common in men having sex with men (MSM). Mycoplasma genitalium is increasingly being reported in this localization, but due to frequent lack of symptoms at this site, clinical significance is still unclear. Rectal prevalence of Mycoplasma hominis and Ureaplasma species is not well studied so far. We aimed to investigate the prevalence and antibiotic sensitivity of rectal Mollicutes in our HIV-cohort.

METHODS

In 227 MSM presenting for annual STI-screening, 317 anorectal swabs were collected from January 2017 to December 2018. PCR was performed for detection of Chlamydia trachomatis, Neisseria gonorrhoeae, M. genitalium and also culture for M. hominis and Ureaplasma spec.

RESULTS

Prevalence for M. genitalium, M. hominis, Ureaplasma spec., C. trachomatis and N. gonorrhoeae was 8.2%, 7.3%, 12.0%, 5.1% and 1.9%, respectively. Patients were asymptomatic with few exceptions. Seroprevalence of syphilis in 227 MSM was 41.9%. In 20 strains of M. genitalium, resistance-associated mutations to macrolides and quinolones were found in 60% and 30%, respectively; in five strains (25%) to both. M. hominis and Ureaplasma spec. frequently occurred combined, mostly in significant quantity consistent with infection. M. hominis and Ureaplasma spec. regularly showed sensitivity to tetracycline.

CONCLUSION

At screening, rectal colonization with Mollicutes was common in our patients, but rarely caused symptoms. Due to rising antibiotic resistance of M. genitalium against quinolones, therapeutic options are increasingly limited. Treatment should be guided by antibiotic resistance testing including quinolones. In persisting anorectal symptoms, M. hominis and Ureaplasma spec. should also be taken into account.

Molecular basis of antimicrobial resistance in Mycoplasma genitalium

Mycoplasma genitalium is a sexually transmitted urogenital pathogen, and infection can result in serious symptoms. As M. genitalium is rather difficult to culture, infections are usually detected by molecular methods. Unfortunately, there has recently been a significant increase in resistance to azithromycin and moxifloxacin used for the treatment of M. genitalium infections. The increased resistance to (often empirically prescribed) M. genitalium treatments has resulted in frequent therapy failures and stresses the need for routine detection of antimicrobial resistance. In M. genitalium, antimicrobial resistance is almost always the result of DNA mutations and thus can easily be detected by molecular techniques. Regrettably, many microbiology laboratories do not use molecular techniques for the detection of bacterial antimicrobial resistance. As molecular tests are becoming available for M. genitalium, both for the establishment of infection and the detection of antimicrobial resistance, it is now more important to ensure that knowledge on the resistance mechanisms is transferred from the laboratory to the clinician. This review will provide a brief summary of the current status of antimicrobial resistance, its molecular mechanisms and the impact on the current status of M. genitalium treatment.

Molecular Testing for Mycoplasma genitalium in the United States: Results from the AMES Prospective Multicenter Clinical Study

A prospective multicenter clinical study involving subjects from 21 sites across the United States was conducted to validate the performance of a new in vitro diagnostic nucleic acid amplification test (NAAT) for the detection of Mycoplasma genitalium.

A prospective multicenter clinical study involving subjects from 21 sites across the United States was conducted to validate the performance of a new in vitro diagnostic nucleic acid amplification test (NAAT) for the detection of Mycoplasma genitalium. Seven urogenital specimen types (n = 11,556) obtained from 1,778 females, aged 15 to 74 years, and 1,583 males, aged 16 to 82 years, were tested with the Aptima Mycoplasma genitalium assay, an investigational transcription-mediated amplification (TMA) NAAT for the detection of M. genitalium 16S rRNA. Infected status for enrolled subjects was established using results obtained from testing either self-collected vaginal swab or clinician-collected male urethral swab specimens with a composite reference method consisting of three transcription-mediated amplification NAATs targeting unique regions of M. genitalium 16S or 23S rRNA. M. genitalium prevalence was 10.2% in females and 10.6% in males; prevalence was high in both symptomatic and asymptomatic subjects for both sexes. Compared to the subject infected status standard, the investigational test had sensitivity and specificity estimates, respectively, of 98.9% and 98.5% for subject-collected vaginal swabs, 92.0% and 98.0% for clinician-collected vaginal swabs, 81.5% and 98.3% for endocervical swabs, 77.8% and 99.0% for female urine, and 98.2% and 99.6% for male urethral swabs, 88.4% and 97.8% for self-collected penile meatal swabs, and 90.9% and 99.4% for male urine specimens. For all seven specimen types, within-specimen positive and negative agreements between the investigational test and the composite reference standard ranged from 94.2% to 98.3% and from 98.5 to 99.9%, respectively. These results provide clinical efficacy evidence for the first FDA-cleared NAAT for M. genitalium detection in the United States.

High Prevalence of Multidrug-Resistant Mycoplasma genitalium in Human Immunodeficiency Virus-Infected Men Who Have Sex With Men in Alabama

We tested for Mycoplasma genitalium in 157 HIV-infected men. Urogenital and rectal prevalence were 10.8% and 6.4%. Macrolide resistance mutations were detected in 70.6% and 80% of urogenital and rectal samples, and fluoroquinolone resistance mutations in 26.7% and 40%, respectively.

British Association for Sexual Health and HIV national guideline for the management of infection with Mycoplasma genitalium (2018)

This is the first British Association for Sexual Health and HIV (BASHH) guideline for the diagnosis and management of Mycoplasma genitalium in people aged 16 years and older. The guideline is primarily aimed at level 3 sexually transmitted infection (STI) management services within the UK, although it could also serve as a reference guide for STI services at other levels.

Long Duration of Asymptomatic Mycoplasma genitalium Infection After Syndromic Treatment for Nongonococcal Urethritis

BACKGROUND

Although Mycoplasma genitalium (MG) is an acknowledged cause of nongonococcal urethritis (NGU), access to diagnostic testing is limited. Syndromic management is common, yet little is known about natural history.

METHODS

Between August 2014 and April 2016, 13 heterosexual men aged ≥16 years with MG were identified within a cohort study of men with and without NGU attending an urban sexually transmitted diseases clinic. Men had 6-7 monthly visits. NGU was defined as ≥5 polymorphonuclear leukocytes per high-power field on urethral Gram stain plus either visible urethral discharge or urethral symptoms. Men with NGU received 1 g of azithromycin. Men with persistent NGU received moxifloxacin 400 mg for 14 days. First-void urine was retrospectively tested for MG using transcription-mediated amplification. Resistance-associated mutations were detected by polymerase chain reaction (PCR) and sequencing. Organism load was determined by quantitative PCR.

RESULTS

Sixty-two percent of MG-positive men had macrolide resistance-mediating mutations (MRMM) at enrollment; 31% had parC mutations (all outside the quinolone resistance-determining region). MG persisted after azithromycin in 7 men, 6 of whom had MRMM. The median duration of persistence in the absence of curative therapy was 143 days (range, 21-228). Five men experienced symptom resolution after azithromycin, but MG persisted for another 89-186 days before moxifloxacin. Organism load was somewhat lower in MRMM than wild-type infections (P = .16).

CONCLUSIONS

The high prevalence of macrolide resistance and long duration of infection after symptom resolution highlights the need for diagnostic MG testing of men with NGU to direct therapy.

Levels of Mycoplasma genitalium Antimicrobial Resistance Differ by Both Region and Gender in the State of Queensland, Australia: Implications for Treatment Guidelines

Mycoplasma genitalium is frequently associated with urogenital and rectal infections, with the number of cases of macrolide-resistant and quinolone-resistant M. genitalium infection continuing to increase. In this study, we examined the levels of resistance to these two common antibiotic treatments in geographically distinct locations in Queensland, Australia. Samples were screened for macrolide resistance-associated mutations using a commercially available kit (ResistancePlus MG; SpeeDx), and quinolone resistance-associated mutations were identified by PCR and DNA sequencing. Comparisons between antibiotic resistance mutations and location/gender were performed. The levels of M. genitalium macrolide resistance were high across both locations (62%). Quinolone resistance mutations were found in ∼10% of all samples, with a number of samples harboring mutations conferring resistance to both macrolides and quinolones. Quinolone resistance was higher in southeast Queensland than in north Queensland, and this was consistent in both males and females (P = 0.007). The M. genitalium isolates in rectal swab samples from males harbored high levels of macrolide (75.9%) and quinolone (19%) resistance, with 15.5% harboring resistance to both classes of antibiotics. Overall, the lowest observed level of resistance was to quinolones in females from north Queensland (1.6%). These data highlight the high levels of antibiotic resistance in M. genitalium isolates within Queensland and the challenges faced by sexually transmitted infection clinicians in managing these infections. The data do, however, show that the levels of antibiotic resistance may differ between populations within the same state, which has implications for clinical management and treatment guidelines. These findings also support the need for ongoing antibiotic resistance surveillance and tailored treatment.

Two cases of multidrug-resistant genitourinary Mycoplasma genitalium infection successfully eradicated with minocycline

Mycoplasma genitalium (MG) infection is a sexually transmitted infection that causes up to 25% of nongonococcal urethritis (NGU). MG strains carrying genetic markers of antimicrobial resistance that may affect treatment outcomes are increasingly recognized as a public health concern. We present two cases of persistent MG NGU with strains carrying both macrolide and quinolone resistance-associated mutations that were eradicated successfully by an extended course of minocycline.

Use of Pristinamycin for Macrolide-Resistant Mycoplasma genitalium Infection

High levels of macrolide resistance and increasing fluoroquinolone resistance are found in Mycoplasma genitalium in many countries. We evaluated pristinamycin for macrolide-resistant M. genitalium in a sexual health center in Australia. Microbiologic cure was determined by M. genitalium–specific 16S PCR 14–90 days after treatment began. Of 114 persons treated with pristinamycin, infection was cured in 85 (75%). This percentage did not change when pristinamycin was given at daily doses of 2 g or 4 g or at 3 g combined with 200 mg doxycycline. In infections with higher pretreatment bacterial load, treatment was twice as likely to fail for each 1 log₁₀ increase in bacterial load. Gastrointestinal side effects occurred in 7% of patients. Pristinamycin at maximum oral dose, or combined with doxycycline, cured 75% of macrolide-resistant M. genitalium infections. Pristinamycin is well-tolerated and remains an option where fluoroquinolones have failed or cannot be used.

New Horizons in Mycoplasma genitalium Treatment

Mycoplasmagenitalium is an important sexually transmitted pathogen responsible for both male and female genital tract disease. Appreciation of its significance in human disease has been hampered by its slow growth in culture, difficulty in isolating it, and lack of commercial molecular-based tests for rapid detection. Comparatively few in vitro data on antimicrobial susceptibility are available due to the scarcity of clinical isolates and difficulty in performing susceptibility tests to determine minimum inhibitory concentrations for M. genitalium. Antimicrobial agents that inhibit protein synthesis such as macrolides, along with fluoroquinolones that inhibit DNA replication, have been the treatments of choice for M. genitalium infections. Even though international guidelines recommend azithromycin as first-line treatment, rapid spread of macrolide resistance as well as emergence of quinolone resistance has occurred. Increasing rates of treatment failure have resulted in an urgent need for new therapies and renewed interest in other classes such as aminocyclitols, phenicols, and streptogramins as treatment alternatives. Limited data for new investigational antimicrobials such as the ketolide solithromycin suggest that this drug may eventually prove useful in management of some resistant M. genitalium infections, although it is not likely to achieve cure rates >80% in macrolide-resistant strains, in a similar range as recently reported for pristinamycin. However, agents with completely new targets and/or mechanisms that would be less likely to show cross-resistance with currently available drugs may hold the greatest promise. Lefamulin, a pleuromutilin, and new nonquinolone topoisomerase inhibitors are attractive possibilities that require further investigation.