Emergence of Mycoplasma genitalium strains showing mutations associated with macrolide and fluoroquinolone resistance in the region Dresden, Germany

[Urethritis-spectrum of pathogens, diagnostics and treatment]

A broad spectrum of bacteria, fungi, protozoa and viruses can cause urethritis. In particular, N. gonorrhoeae, C. trachomatis, M. genitalium and T. vaginalis are the focus of diagnostic considerations as classic pathogens associated with sexually transmitted infections (STI). A step-by-step procedure is needed to make a definitive diagnosis. Microscopy with a staining preparation provides an initial differentiation between gonoccocal and non-gonococcal urethritis in symptomatic men as a point-of-care (POC) test. Nucleic acid amplification technology (NAAT) is used for specific and sensitive pathogen detection and, as a multiplex diagnostic test, offers the possibility of detecting several organisms from the same sample. In addition, compared to culture, no vital organisms are required, which allows the collection and use of more diverse and less invasive biological samples (e.g. first stream urine in men or vaginal swabs). Susceptibility testing by culture remains essential for N. gonorrhoeae as resistance is emerging. The treatment of urethritis depends on the suspected or proven pathogen according to the current guidelines. Treatment failure can be caused by many factors (coinfection, lack of therapy adherence, reinfection or resistance of the pathogen) and requires a repeated diagnostic and therapeutic procedure and differentiated approach.

Challenges of in vitro propagation and antimicrobial susceptibility testing of Mycoplasma genitalium

The sexually transmitted bacterial pathogen Mycoplasma genitalium has proved a complex organism to work with in the laboratory setting. Exhibiting an extremely fastidious nature, successful in vitro propagation of M. genitalium has remained elusive for many researchers. Antimicrobial resistance to both first- and second-line recommended therapies (macrolides and fluoroquinolones, respectively) is commonly reported. However, phenotypic susceptibility testing is not routinely performed, due to the difficulties of in vitro growth. Instead, molecular detection of known resistance determinants is used to infer susceptibility/resistance. However, associations between determinant detection and clinical treatment failure are not always clear. Furthermore, molecular assays have limited use for detection of emerging resistance mechanisms. The present review collates and discusses the development of successful culture systems for initial isolation of this organism and current methodologies employed for phenotypic susceptibility testing to aid researchers in this field. As with Neisseria gonorrhoeae, future treatment options are extremely limited for M. genitalium and, if this sexually transmitted infection is to remain treatable, phenotypic susceptibility testing will play an invaluable role in evaluation of potential therapeutics. As such, retainment of these techniques is imperative.

Molecular Typing Reveals Distinct Mycoplasma genitalium Transmission Networks among a Cohort of Men Who Have Sex with Men and a Cohort of Women in France

Mycoplasma genitalium causes sexually transmitted infecti.ons in men and women. Treatment failures to macrolides and fluoroquinolones have been reported worldwide. Although the mgpB typing method has often been used in M. genitalium-infected men who have sex with men (MSM), limited typing data are available for M. genitalium-infected women. In this study, we aimed to investigate the genetic relationship between M. genitalium strains and their antibiotic resistance profile in a cohort of MSM (86.2% on HIV preexposure prophylaxis [PrEP], 13.8% HIV positive) and a large cohort of women using mgpB/MG309 typing. The mgpB types were determined in 374 samples from 305 women and 65 MSM. Three MSM and one woman had two concurrent or subsequent samples. Macrolide and fluoroquinolone resistance-associated mutations were searched in the 23S rRNA as well as parC and gyrA genes. The mgpB phylogenetic construction revealed three large clusters that differed according to sexual practices and geographical origin of patients. The prevalence of macrolide and fluoroquinolone resistance was significantly higher in MSM compared with women (95.4% vs. 14.1% and 30.6% vs. 7.2%, p < 0.001, respectively). The macrolide resistance spread was polyclonal in both populations, but clonal diffusion of two dual-resistant types was observed in PrEP users in association with high antibiotic pressure and dense connectivity in this population.

Molecular Tools for Typing Mycoplasma pneumoniae and Mycoplasma genitalium

Mycoplasma pneumoniae and Mycoplasma genitalium are cell wall-less bacteria with strongly reduced genome content and close phylogenetic relatedness. In humans, the only known natural host, the microorganisms colonize the respiratory or genitourinary mucosa and may cause a broad range of clinical presentations. Besides fundamental differences in their tissue specificity, transmission route, and ability to cause prevalence peaks, both species share similarities such as the occurrence of asymptomatic carriers, preferred populations for infection, and problems with high rates of antimicrobial resistance. To further understand the epidemiology of these practically challenging bacteria, typing of strains is necessary. Since the cultivation of both pathogens is difficult and not performed outside of specialized laboratories, molecular typing methods with adequate discriminatory power, stability, and reproducibility have been developed. These include the characterization of genes containing repetitive sequences, of variable genome regions without the presence of repetitive sequences, determination of single and multi-locus variable-number tandem repeats, and detection of single nucleotide polymorphisms in different genes, respectively. The current repertoire of procedures allows reliable differentiation of strains circulating in different populations and in different time periods as well as comparison of strains occurring subsequently in individual patients. In this review, the methods for typing M. pneumoniae and M. genitalium, including the results of their application in different studies, are summarized and current knowledge regarding the association of typing data with the clinical characteristics of infections is presented.

Mycoplasma genitalium prevalence and macrolide resistance-associated mutations and coinfection with Chlamydia trachomatis in Southern Jutland, Denmark

This study aims to investigate prevalence of Mycoplasma genitalium and macrolide resistance‐associated mutations and coinfection with other sexually transmitted bacteria in Southern Jutland, Denmark, where this information is very limited. Urinary samples from patients suspected of sexually transmitted bacterial infections collected at primary healthcare facilities in Southern Jutland are routinely tested for Chlamydia trachomatis and Neisseria gonorrhoeae. 601 of these samples were analysed with SpeeDx MG+23S reagents, which can detect M. genitalium and macrolide resistance‐mediating mutations in the 23S rRNA gene. Moreover, 147 C. trachomatis positive urinary samples from routine test were also analysed with the PCR assay to detect M. genitalium. 72 out of 601 samples were detected positive for C. trachomatis (12%), five samples (0.83%) positive for N. gonorrhoeae and 25 samples positive for M. genitalium (4.2%). 14 of the 25 M. genitalium samples were detected having 23S rRNA gene mutations associated with macrolide resistance (56%). 25 of 147 C. trachomatis positive samples were tested positive for M. genitalium (17%) and two of them were positive for M. genitalium and N. gonorrhoeae (1.4%). The high prevalence of M. genitalium and macrolide resistance‐associated mutation and the coinfection with C. trachomatis in the region suggesting that M. genitalium testing should be included in routine sexually transmitted infection screening.

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.

Mycoplasma genitalium infections can comprise a mixture of both fluoroquinolone-susceptible and fluoroquinolone-resistant strains

BACKGROUND

Mycoplasma genitalium was recently added to the CDC's antimicrobial resistance threats 'watch list', as it has rapidly become resistant to mainstay treatments. In Australia, treatment failure with fluoroquinolones remain commonplace, even when Sanger sequencing fails to identify evidence of resistance mutations.

METHODS

Suspecting that Sanger sequencing may miss low-load mixed infections, we applied three additional PCR-based approaches (allele-specific primer-based PCR, probe-based PCR and amplicon deep sequencing) to detect mutations associated with fluoroquinolone susceptibility/resistance. We focused on resistance mutations at amino acid positions 83 and 87 of parC, as these were previously shown to be common in Australia.

RESULTS

Our results showed evidence of mixtures of fluoroquinolone-susceptible and -resistant strains in up to 27/423 samples (6.4%). These included 1 sample that was indicated to be mixed by Sanger sequencing and all three additional PCR methods, 6 samples detected by two or more of the additional PCRs but not by Sanger sequencing and finally 20 samples that were detected by only one of the additional PCR methods. A key question was whether Sanger sequencing failed to detect fluoroquinolone resistance in any samples; overall, we observed that Sanger sequencing failed to detect fluoroquinolone resistance in up to 3.8% (16/423) of samples.

CONCLUSIONS

The presence of mixed susceptibility infections may have important implications for clinical patient management and stresses the need for appropriate detection of resistance and selection of antimicrobials to ensure appropriate treatment of M. genitalium infections.

Mycoplasma genitalium Antimicrobial Resistance in Community and Sexual Health Clinic Patients, Auckland, New Zealand

Our retrospective study compared genotypic antimicrobial resistance in Mycoplasma genitalium-positive specimens collected from 48 community and 33 sexual health clinic (SHC) patients. Macrolide resistance was similar in community (75%) and SHC (76%) patients. We observed no significant difference in fluoroquinolone resistance between community (19%) and SHC (27%) patients (p = 0.66).

High Prevalence and High Rate of Antibiotic Resistance of Mycoplasma genitalium Infections in Men who Have Sex with Men. A Sub-Study of the ANRS Ipergay PrEP Trial

BACKGROUND

Mycoplasma genitalium (MG) is an emerging pathogen among men who have sex with men (MSM) with raising rates of antibiotic resistance. In this study, we assessed the prevalence and incidence of MG infection in MSM enrolled in the open-label phase of the ANRS IPERGAY trial with on demand TDF/FTC for HIV prevention and the impact of doxycycline post-exposure prophylaxis (PEP).

METHODS

210 subjects were tested at baseline and at 6 months by real-time PCR assays for MG detection in urine samples, oro-pharyngeal and anal swabs. Resistance to azithromycin (AZM), to fluoroquinolones (FQ) and to doxycycline were investigated in the French National Reference Centre of bacterial STI.

RESULTS

The all-site prevalence of MG at baseline was 10.5% [6.3% in urine samples, 4.3% in anal swabs and 0.5% in throat swabs] and remained unchanged at 6 months whether or not PEP was used: 9.9% overall, 10.2% with PEP and 9.6% without. The overall rate of MG resistance (prevalent and incident cases) to AZM and FQ was 67.6% and 9.1%, respectively, with no difference between arms. An in vivo mutation of the MG 16S rRNA which could be associated with tetracycline resistance was observed in 12.5% of specimens tested.

CONCLUSIONS

The prevalence of MG infection among MSM on PrEP was high and its incidence was not decreased by doxycycline prophylaxis with a similar high rate of AZM- and FQ-resistance, raising challenging issues for the treatment of this STI and supporting current recommendations to avoid testing or treatment of asymptomatic MG infection.

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.

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.

Mycoplasma genitalium Infections With Macrolide and Fluoroquinolone Resistance-Associated Mutations in Heterosexual African American Couples in Alabama

BACKGROUND

Mycoplasma genitalium (MG) is a sexually transmitted pathogen associated with inflammatory syndromes in men and women. Macrolides and fluoroquinolones are recommended MG treatments. The frequency of MG strains with macrolide resistance-associated mutations (MRMs) and quinolone resistance-associated mutations (qRMs) is increasing worldwide, however these data are sparse in populations in the United States.

METHODS

We investigated the prevalence of MG infections with MRMs and qRMs and MG infection concordance within African American couples in Birmingham, AL. We used a real-time polymerase chain reaction to detect MG and identify MRMs. quinolone resistance-associated mutations were detected using traditional polymerase chain reactions amplifying regions in gyrA, gyrB, parC, and parE. The MG concordance in couples was evaluated by MG positivity and MG genotypes.

RESULTS

Oral, anal, urine, and/or vaginal specimens were tested from 116 couples. Twenty-eight (12.1%) participants comprising 22 couples tested MG-positive (11.2% in men and 12.9% in women). Macrolide resistance-associated mutations were detected in 17 (60.7%) MG-positive participants, with gender-specific resistance rates of 69.2% for men and 53.3% for women. quinolone resistance-associated mutations were detected in 3 (11.1%) MG-positive participants, all of whom also had MRMs. By MG positivity status, 27.3% of couples were concordant. If MG strain genotypes are also considered, then concordance was 20.0%.

CONCLUSIONS

Among heterosexual African Americans with MG infection, about 60% had strains with MRMs and 11% had strains with both MRMs and qRMs, highlighting the potential for MG treatment failure to not only macrolides, but also quinolones. These findings may help to guide clinicians in MG testing and treatment decisions in the United States.

Bacterial sexually transmitted infections

Worldwide, the incidence of bacterial sexually transmitted infections (STIs) has shown a significant increase in recent years. In Germany, this circumstance is reflected by a rise in the number of reported syphilis cases. There has also been an uptick in the incidence of non-notifiable STIs such as gonorrhea and infections caused by Chlamydia trachomatis and Mycoplasma genitalium. A key factor in the spread of these infections is their varied clinical presentation, which includes urogenital, pharyngeal and rectal involvement as well as a large number of asymptomatic cases. New real-time multiplex PCR methods allow for rapid and targeted detection of STI pathogens. The most common bacterial STI is urogenital chlamydial infection caused by serovars D-K, which affects young adults in particular. Lymphogranuloma venereum (LGV) caused by L serovars often presents as chlamydial proctitis. In recent years, Neisseria (N.) gonorrhoeae has shown a significant development of resistance, with high-level monoresistance and multiresistance to antibiotics commonly used for treatment. It is therefore imperative that sensitivity testing of N. gonorrhoeae be performed in addition to nucleic acid amplification tests (NAATs). Increased drug resistance has also been observed for Mycoplasma genitalium, a fact that complicates treatment.

Mycoplasma genitalium in Symptomatic Male Urethritis: Macrolide Use Is Associated With Increased Resistance

BACKGROUND

Mycoplasma genitalium (MG) causes symptomatic urethritis in men, and can infect alone or together with other sexually transmitted infection (STI) agents.

METHODS

The prevalence of MG and other STIs was determined in 1816 men with symptomatic urethritis. Resistance of MG to macrolides and fluoroquinolones was determined by sequencing; the impact of recent antimicrobial usage on the distribution of MG single or mixed infections was determined.

RESULTS

Overall, prevalence of MG infection was 19.7% (358/1816). Fifty-four percent (166/307) of MG infections occurred alone in the absence of other STI agents. Men with single MG infection self-administered or were prescribed antibiotics more often in the 30 days prior to enrollment than subjects with urethritis caused by MG coinfection (P < .0001). Higher rates (96.7%) of infection with macrolide resistance in MG were identified in men who had taken macrolides prior to enrollment (P < .03). Overall, 88.9% (303/341) of 23S ribosomal RNA (rRNA) genes contained mutations responsible for macrolide resistance; 89.5% (308/344) of parC and 12.4% (42/339) of gyrA genes had mutations responsible for fluoroquinolone resistance. Approximately 88% (270/308) of MG had combined mutations in 23S rRNA and parC genes; 10.4% (32/308) had mutations in all 3 genes.

CONCLUSIONS

MG was the single pathogen identified in 11% of men with symptomatic urethritis. Overall, nearly 90% of MG infections were resistant to macrolides and fluoroquinolones. Men who took macrolides in the 30 days prior to enrollment had higher rates (97%) of macrolide-resistant MG. Resistance was associated with numerous mutations in 23SrRNA, parC, and gyrA genes.

Diagnosis of some genital-tract infections: part 2. Molecular tests and the new challenges

Promptly and accurately diagnosing genital-tract infections is key to instituting appropriate treatment and control of sexually transmitted infections (STIs). Ano-genital tract testing for STIs in the last two decades has not entirely moved away from insensitive methods but it is now at least dominated by highly sensitive molecular methods. These tests can be ordered through the internet for use at home, with self-taken specimens then returned, usually by post, to a clinic or laboratory for testing. The increasing ease of access of the public to this situation, together with increasing on-line health-seeking behaviour, has resulted in a gap between commercial and NHS management pathways for STIs. Crucially, patients who order multiplex test kits on-line for use at home, and other non-specialists, may not realize that it is worthwhile testing only for Neisseria gonorrhoeae, Chlamydia trachomatis, and possibly Trichomonas vaginalis, and Mycoplasma genitalium if the person is symptomatic or their current partner is infected. The detection and recommended treatment of micro-organisms which to some extent are part of the genital-tract microbiome, such as Mycoplasma hominis, Ureaplasma spp. or Gardnerella vaginalis, which do not cause symptoms in the majority of those infected, cannot be recommended. We argue that a shift from specialist-led to patient- and non-specialist-led STI management, in the presence of a clinical leadership vacuum, has increased the risk of inappropriate and unnecessary treatment which will drive macrolide, tetracycline and metronidazole antimicrobial resistance. However, in the past 5–6 years several groups have been able to show the value of on-line testing as a consequence of targeting the most important micro-organisms and using molecular tests to allow rapid and appropriately informed treatment. This should herald a brighter future, although there is still a need for leadership to expertly guide commercial and NHS sectors alike. In turn, this requires dedicated genito-urinary medicine commissioning to be maintained at a time when it appears to be most under threat.

Mycoplasma genitalium and antimicrobial resistance in Europe: a comprehensive review

Antibiotic resistance in Mycoplasma genitalium has been emerging in Europe. Also, discrepancies on the management and treatment of sexually transmitted infections may have distinctly influenced the prevalence of antimicrobial resistance among European countries. This comprehensive review of the literature published between 2012 and 2018 updates antimicrobial resistance data in M. genitalium in Europe. Overall, macrolide resistance is rapidly increasing in this region, where many countries are exceeding 50%. The limited data regarding fluoroquinolone resistance estimate a prevalence of 5% (interquartile range, 5–6%). The study supports the need to conduct representative and well-defined surveillance on antimicrobial resistance in M. genitalium at both local and European levels. Also, further investigations on new promising antibiotics are required to fight against M. genitalium that may soon become untreatable.

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.

MgpB Types among Mycoplasma genitalium Strains from Men Who Have Sex with Men in Berlin, Germany, 2016-2018

Mycoplasma genitalium is a cell wall-less bacterium causing urethritis and other sexually transmitted diseases. Despite a strongly conserved genome, strains in clinical samples can be typed by different methods. To obtain data from the risk population of men having sex with men, we analyzed the typing region in the gene coding for the MgpB adhesin of M. genitalium first in 163 and 45 follow-up samples among patients of two specialized practices in Berlin, Germany. Strains belong to 43 different mgpB types emphasizing the diversity of the genome region. With respect to 133 types previously described, 27 new types were found. However, the majority of strains (64.4%) were assigned to types 4, 6, 113, and 108, respectively. A correlation between mgpB type and the occurrence of mutations associated with macrolide and quinolone resistance was not demonstrated. Investigation of follow-up samples from 35 patients confirmed the same mgpB and, additionally, MG_309 types in 25 cases. In 10 cases, differences between types in subsequent samples indicated an infection with a genetically different strain in the period between samplings. MgpB/MG_309 typing is a useful method to compare M. genitalium strains in samples of individual patients as well as those circulating in different populations

Mycoplasma genitalium prevalence in Welsh sexual health patients: Low antimicrobial resistance markers and no association of symptoms to bacterial load

OBJECTIVES

Mycoplasma genitalium (MG) is a common cause of sexually transmitted infection, however no prevalence data is available for Wales. MG was detected by qPCR (quantitative) as well as two separate SpeeDx commercial assays, and related to clinical symptoms, age, gender and sample type.

METHODS

Cervical swabs, urethral swabs and/or urine were collected from 1000 patients at walk-in sexual health clinics at 3 Welsh health centres from October 2017-October 2018. Extracted DNA was investigated to determine concordance between an in-house quantitative PCR, SpeeDx ResistancePlus® MG and the SpeeDx MG + parC (beta 2) assays; mutations in parC were substantiated by Sanger sequencing.

RESULTS

MG was detected in 17/600 female patients (2.7%) and 13/400 (3.5%) male patients, with a 100% concordance between in-house qPCR and both SpeeDx assays. Macrolide resistance was low (relative to other studies), but more common in males (4/13; 30.8%) than females (2/17; 11.8%) and the only fluoroquinolone resistant sample (3.4% overall) was also macrolide resistant and detected from an MSM. Vaginitis was clinically apparent in 12/17 MG-positive females (2 with additional cervicitis, 1 with additional pelvic inflammatory disease), while 7 MG-positive males were asymptomatic. MG bacterial load did not correlate to clinical symptoms and females (4559 ± 1646/ml) had significantly lower MG load than males (84,714 ± 41,813/ml; p = 0.0429).

CONCLUSIONS

MG prevalence and antibiotic resistance in Welsh sexual health clinics is low. MG bacterial load did not correlate to clinical presentation, men have higher MG load/ml in urine than women, genders have different age bias for MG prevalence and urine and swabs are equivalent for detecting MG.

Prevalence of macrolide- and fluoroquinolone-resistant Mycoplasma genitalium strains in clinical specimens from men who have sex with men of two sexually transmitted infection practices in Berlin, Germany

OBJECTIVES

The cell-wall-less Mollicutes species Mycoplasma genitalium is a sexually transmitted micro-organism that causes different male and female genital tract infections. In recent years, resistance of the pathogen to macrolides and fluoroquinolones has been increasingly reported worldwide and is more frequent in risk groups.

METHODS

To determine the rates of antimicrobial resistance, M. genitalium strains in 195 specimens from 154 outpatients (154 first and 41 follow-up samples) treated in two specialised practices between September 2017 and December 2018 in Berlin, Germany, were analysed.

RESULTS

The included patients were predominantly men who have sex with men (MSM) (91.6%) and were HIV-positive in many cases (49.4%). Only 27.3% of M. genitalium-positive patients reported symptoms. Among the first samples (mainly rectal swabs) (57.8%), mutations associated with macrolide (23S rRNA) and quinolone (parC gene) resistance were detected in 79.9% and 13.0% of strains, respectively. Resistance to both classes of antibiotics was found in 11.7% of specimens. Changes of A→G at position 2072 of 23S rRNA and of serine at position 83 of ParC were the most frequent alterations.

CONCLUSION

Although azithromycin is recommended as a first-line antibiotic to treat infections with M. genitalium in MSM, according to these data its use must be highly limited in Berlin. Besides the need for resistance studies regarding strains circulating in other locations and among different patient groups in Germany, the results emphasise the importance of intensified antibiotic resistance testing of M. genitalium to avoid a further increase in treatment failures in infections with this emerging human pathogen.

Extragenital Mycoplasma genitalium infections among men who have sex with men

OBJECTIVES

There are limited data on the prevalence of Mycoplasma genitalium (Mgen) coinfection with rectal chlamydia (Chlamydia trachomatis (CT)) and rectal gonorrhoea (Neisseria gonorrhoeae (NG)) infections and few studies examining the prevalence of pharyngeal Mgen in men who have sex with men (MSM). Using transcription-mediated amplification assay, this study aimed to determine the proportion of rectal CT and rectal NG infections in MSM who are coinfected with rectal Mgen, and the proportion of MSM with Mgen detected in the pharynx in order to inform clinical practice.

METHODS

This was a cross-sectional study conducted at Melbourne Sexual Health Centre in Australia. Consecutively collected rectal swabs from MSM that tested positive for CT (n=212) or NG (n=212), and consecutively collected pharyngeal samples (n=480) from MSM were tested for Mgen using the Aptima Mycoplasma genitalium Assay (Hologic, San Diego). Samples were linked to demographic data and symptom status.

RESULTS

Rectal Mgen was codetected in 27 of 212 rectal CT (13%, 95% CI 9 to 18) and in 29 of 212 rectal NG (14%, 95% CI 9 to 19) samples, with no difference in the proportion positive for Mgen. MSM with rectal CT/Mgen coinfection had more sexual partners than those with rectal CT monoinfection (mean 6 vs 11, p=0.06). MSM with rectal NG/Mgen coinfection were more likely to be HIV-positive than those with rectal NG monoinfection (OR=2.96, 95% CI 1.21 to 7.26, p=0.023). MSM with rectal CT/Mgen coinfection were more likely to be using pre-exposure prophylaxis than MSM with rectal NG/Mgen coinfection (OR 0.25, 95% CI 0.10 to 0.65, p=0.002). Pharyngeal Mgen was uncommon and detected in 8 of 464 samples (2%, 95% CI 1% to 3%). Pharyngeal Mgen was associated with having a rectal STI (OR=10.61, 95% CI 2.30 to 48.87, p=0.002), and there was a borderline association with being HIV-positive (p=0.079).

CONCLUSION

These data indicate one in seven MSM treated for rectal CT or rectal NG will have undiagnosed Mgen that is potentially exposed to azithromycin during treatment of these STIs. Rectal Mgen coinfection was associated with specific risk factors which may inform testing practices. Pharyngeal Mgen was uncommon.

Bakterielle sexuell übertragbare Infektionen

Bakterielle sexuell übertragbare Infektionen (STI) zeigen seit Jahren weltweit eine deutliche Zunahme. In Deutschland wird diese Tatsache durch steigende Meldezahlen für Syphilis bestätigt. Auch für die nicht meldepflichtigen STI Gonorrhoe, Chlamydia-trachomatis- und Mycoplasma-genitalium-Infektionen wird eine zunehmende Inzidenz beobachtet. Entscheidend für die Weiterverbreitung ist, dass das breite klinische Spektrum, welches neben Urogenitalsitus auch Pharynx und Rektum einbezieht, durch eine hohe Zahl asymptomatischer Verläufe ergänzt wird. Neue Real-Time-Multiplex-Diagnostikverfahren ermöglichen einen schnellen und gezielten Nachweis von STI-Erregern. Die häufigste bakterielle STI ist die urogenitale Chlamydieninfektion mit den Serovaren D-K, die besonders bei jungen Erwachsenen auftritt. Einer Chlamydien-Proktitis kann eine Infektion mit L-Serovaren und damit eine Lymphogranuloma-venereum (LGV)-Infektion zugrunde liegen. Neisseria (N.) gonorrhoeae zeigte in den letzten Jahren eine starke Resistenzentwicklung mit Ausbildung von Einzel- und Multiresistenzen gegenüber bisher gängigen Antibiotika. Daher ist für N. gonorrhoeae zusätzlich zum nucleic acid amplification test (NAAT) eine kulturelle Empfindlichkeitstestung durchzuführen. Auch für Mycoplasma genitalium sind Resistenzentwicklungen bekannt, die eine Therapie erschweren können.

Turning the Tide against Antibiotic Resistance by Evaluating Novel, Halogenated Phenazine, Quinoline, and NH125 Compounds against Ureaplasma Species Clinical Isolates and Mycoplasma Type Strains

Escalating levels of antibiotic resistance in mycoplasmas, particularly macrolide resistance in Mycoplasma pneumoniae and M. genitalium, have narrowed our antibiotic arsenal. Further, mycoplasmas lack a cell wall and do not synthesize folic acid, rendering common antibiotics, such as beta-lactams, vancomycin, sulfonamides, and trimethoprim, of no value.

Escalating levels of antibiotic resistance in mycoplasmas, particularly macrolide resistance in Mycoplasma pneumoniae and M. genitalium, have narrowed our antibiotic arsenal. Further, mycoplasmas lack a cell wall and do not synthesize folic acid, rendering common antibiotics, such as beta-lactams, vancomycin, sulfonamides, and trimethoprim, of no value. To address this shortage, we screened nitroxoline, triclosan, and a library of 20 novel, halogenated phenazine, quinoline, and NH125 analogues against Ureaplasma species and M. hominis clinical isolates from urine. We tested a subset of these compounds (n = 9) against four mycoplasma type strains (M. pneumoniae, M. genitalium, M. hominis, and Ureaplasma urealyticum) using a validated broth microdilution or agar dilution method. Among 72 Ureaplasma species clinical isolates, nitroxoline proved most effective (MIC₉₀, 6.25 µM), followed by an N-arylated NH125 analogue (MIC₉₀, 12.5 µM). NH125 and its analogue had significantly higher MICs against U. urealyticum isolates than against U. parvum isolates, whereas nitroxoline did not. Nitroxoline exhibited bactericidal activity against U. parvum isolates but bacteriostatic activity against the majority of U. urealyticum isolates. Among the type strains, the compounds had the greatest activity against M. pneumoniae and M. genitalium, with 8 (80%) and 5 (71.4%) isolates demonstrating MICs of ≤12.5 µM, respectively. Triclosan also exhibited lower MICs against M. pneumoniae and M. genitalium. Overall, we identified a promising range of quinoline, halogenated phenazine, and NH125 compounds that showed effectiveness against M. pneumoniae and M. genitalium and found that nitroxoline, approved for use outside the United States for the treatment of urinary tract infections, and an N-arylated NH125 analogue demonstrated low MICs against Ureaplasma species isolates.

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.

Mycoplasma genitalium Infection in Kenyan and US Women

BACKGROUND

Little is known about the natural history of Mycoplasma genitalium (MG) infection in women. We retrospectively tested archived vaginal fluid samples to assess MG prevalence, incidence, persistence, recurrence and antimicrobial resistance markers among women participating in the Preventing Vaginal Infections trial, a randomized trial of monthly presumptive treatment to reduce vaginal infections.

METHODS

High-risk, nonpregnant, HIV-negative women aged 18 to 45 years from Kenya and the United States were randomized to receive metronidazole 750 mg + miconazole 200 mg intravaginal suppositories or placebo for 5 consecutive nights each month for 12 months. Clinician-collected swabs containing cervicovaginal fluid were tested for MG using Hologic nucleic acid amplification testing at enrollment and every other month thereafter. Specimens that were MG+ underwent additional testing for macrolide resistance-mediating mutations by DNA sequencing.

RESULTS

Of 234 women enrolled, 221 had available specimens and 25 (11.3%) had MG at enrollment. Among 196 women without MG at enrollment, there were 52 incident MG infections (incidence, 33.4 per 100 person-years). Smoking was independently associated with incident MG infection (adjusted hazard ratio, 3.02; 95% confidence interval, 1.32-6.93), and age less than 25 years trended toward an association (adjusted hazard ratio, 1.70; 95% confidence interval, 0.95-3.06). Median time to clearance of incident MG infections was 1.5 months (interquartile range, 1.4-3.0 months). Of the 120 MG+ specimens, 16 specimens from 15 different women were macrolide resistance-mediating mutation positive (13.3%), with no difference by country.

CONCLUSIONS

M. genitalium infection is common among sexually active women in Kenya and the Southern United States. Given associations between MG and adverse reproductive health outcomes, this high burden of MG in reproductive-aged women could contribute to substantial morbidity.

Prevalence of Mycoplasma genitalium and mutations associated with macrolide and fluoroquinolone resistance in Finland

The aim was to examine the prevalence of Mycoplasma genitalium and to determine the prevalence of mutations leading to resistance to macrolides and fluoroquinolones in a sexually transmitted infection clinic setting in Finland, and as a service evaluation, to validate the performance of a commercial Aptima® Mycoplasma genitalium assay. Urogenital samples were studied for M. genitalium with an automated commercial Aptima® Mycoplasma genitalium assay on the Panther® system (Hologic), and with an in-house real-time polymerase chain reaction (PCR) (mgpB). Positive specimens were further studied for mutations associated with macrolide resistance within the 23S rRNA gene and the known quinolone resistance-determining regions within genes gyrA, gyrB and parC. Altogether 17/303 (5.6%) of samples contained M. genitalium by either test. Two of the samples positive by the Aptima assay were not detected by the in-house PCR assay, although the internal control (beta-globin gene) was amplified. The Aptima assay gave an invalid result for five samples, all of which were negative by the in-house PCR. Mutations resulting in macrolide resistance were detected in 30.8% of M. genitalium-positive specimens. Prevalence of M. genitalium infections in the specimens tested is similar to that in other parts of Europe, 5.6%. The Aptima® Mycoplasma genitalium assay detected slightly more positives than the in-house PCR assay. Mutations resulting in macrolide resistance were common in M. genitalium and detection of these mutations is recommended in diagnostic laboratories to assist in selection of treatment.

Mycoplasma genitalium Infection in Adults Reporting Sexual Contact with Infected Partners, Australia, 2008-2016

Data on the likelihood of Mycoplasma genitalium infection in sexual contacts, particularly for men who have sex with men (MSM), are needed to form an evidence base for guidelines. We conducted a cross-sectional analysis of patients attending a sexual health clinic in Melbourne, Victoria, Australia, during 2008-2016. We calculated the proportion of contacts with M. genitalium infection and determined factors associated with infection. Among those patients reporting sexual contact with an M. genitalium-infected person, 48.2% of women, 31.0% of heterosexual men, and 41.7% of MSM were infected. Among heterosexual contacts, women were twice as likely to be infected; among MSM, rectal infection was more common than urethral infection; and among persons within heterosexual partnerships, concordance of infection was high. High positivity among female and MSM contacts and high concordance in heterosexual partnerships provide some justification for presumptive treatment; however, clinicians should consider antimicrobial drug resistance and toxicity of quinolones.

Macrolide and fluoroquinolone resistance in Mycoplasma genitalium in two Swedish counties, 2011-2015

Mycoplasma genitalium, causing non-gonococcal non-chlamydial urethritis and associated with cervicitis, has developed antimicrobial resistance (AMR) to both the macrolide azithromycin (first-line treatment) and the fluoroquinolone moxifloxacin (second-line treatment). Our aim was to estimate the prevalence of resistance, based on genetic AMR determinants, to these antimicrobials in the M. genitalium population in two Swedish counties, Örebro and Halland, 2011-2015. In total, 672 M. genitalium positive urogenital samples were sequenced for 23S rRNA and parC gene mutations associated with macrolide and fluoroquinolone resistance, respectively. Of the samples, 18.6% and 3.2% in Örebro and 15.2% and 2.7% in Halland contained mutations associated with macrolide and fluoroquinolone resistance, respectively. The predominating resistance-associated mutations in the 23S rRNA gene was A2059G (n = 39) in Örebro and A2058G (n = 13) and A2059G (n = 13) in Halland. The most prevalent possible resistance-associated ParC amino acid alterations were S83I (n = 4) in Örebro and S83N (n = 2) in Halland. Resistance-associated mutations to both macrolides and fluoroquinolones were found in 0.7% of samples. Our findings emphasize the need for routine AMR testing, at a minimum for macrolide resistance, of all M. genitalium-positive samples and regular national and international surveillance of AMR in M. genitalium, to ensure effective patient management and rational antimicrobial use.

Macrolide resistance in Mycoplasma genitalium from female sex workers in Belgium

OBJECTIVES

Mycoplasma genitalium is emerging as an aetiological agent of sexually transmitted infections (STIs). Although M. genitalium is commonly treated with azithromycin, macrolide resistance associated with point mutations in the 23S rRNA gene is emerging.

METHODS

In this study, the prevalence of M. genitalium and macrolide resistance in female sex workers (FSW) in Belgium was evaluated by a prospective study conducted between 2015 and 2016. Vaginal swabs were sampled from 303 FSW who underwent testing for M. genitalium along with standard STI screening. All samples positive for M. genitalium were subsequently tested for mutations associated with macrolide resistance.

RESULTS

M. genitalium was detected in 10.8% of participants and macrolide resistance-associated mutations (A2058G and A2059G) were found in 6.5% of isolates.

CONCLUSIONS

M. genitalium is clearly present in FSW in Belgium. In contrast to other reports, for now the occurrence of macrolide resistance appears limited in this specific target population.

Mycoplasma genitalium Macrolide and Fluoroquinolone Resistance Detection and Clinical Implications in a Selected Cohort in New Zealand

Mycoplasma genitalium has been associated with infections of the genitourinary tract, and prevalence is secondary to Chlamydia trachomatis The clinical observation of increasing treatment failure indicating antibiotic resistance, especially in cases of recurrent urethritis, has been confirmed by molecular testing. Mutations in the 23S rRNA gene can cause macrolide resistance, and topoisomerase/gyrase mutations can cause fluoroquinolone resistance. In this study, 115 M. genitalium DNA-positive samples were analyzed. Eighty-nine (77.4%) samples had a 23S rRNA mutation present, and 26 (22.6%) were wild type (no resistance mutation). Fluoroquinolone mutation screening was performed on 86 (74.8%) of the 115 samples, of which 20 (23.3%) samples had a mutation or mutations associated with increased resistance. This study shows the increasing antibiotic resistance in New Zealand and the need for appropriate guidelines to treat at-risk patients.

Developing a Public Health Response to Mycoplasma genitalium

Although Mycoplasma genitalium is increasingly recognized as a sexually transmitted pathogen, at present there is no defined public health response to this relatively newly identified sexually transmitted infection. Currently available data are insufficient to justify routinely screening any defined population for M. genitalium infection. More effective therapies, data on acceptability of screening and its impact on clinical outcomes, and better information on the natural history of infection will likely be required before the value of potential screening programs can be adequately assessed. Insofar as diagnostic tests are available or become available in the near future, clinicians and public health agencies should consider integrating M. genitalium testing into the management of persons with sexually transmitted infection (STI) syndromes associated with the infection (ie urethritis, cervicitis, and pelvic inflammatory disease) and their sex partners. Antimicrobial-resistant M. genitalium is a significant problem and may require clinicians and public health authorities to reconsider the management of STI syndromes in an effort to prevent the emergence of ever more resistant M. genitalium infections.

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

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

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.

Increasing Macrolide and Fluoroquinolone Resistance in Mycoplasma genitalium

Escalating resistance to azithromycin and moxifloxacin is being reported for Mycoplasma genitalium in the Asia-Pacific region. Analyzing 140 infections, we found pretreatment fluoroquinolone-resistance mutations in parC (13.6%) and gyrA (5%). ParC S83 changes were associated with moxifloxacin failure. Combined macrolide/fluoroquinolone-resistance mutations were in 8.6% of specimens, for which recommended therapies would be ineffective.

Prevalence of macrolide and fluoroquinolone resistance-mediating mutations in Mycoplasma genitalium in five cities in Russia and Estonia

Background and objective

Resistance in the sexually transmitted bacterium Mycoplasma genitalium to all recommended therapeutic antimicrobials have rapidly emerged. However, to date, internationally reported resistance surveillance data for M. genitalium strains circulating in Eastern Europe are entirely lacking. The aim of this study was to estimate the prevalence of macrolide and fluoroquinolone resistance-associated mutations in M. genitalium in four cities in Russia and one in Estonia, 2013–2016.

Materials and methods

Consecutive urogenital samples found positive for M. genitalium during diagnostic testing were retrospectively analyzed for resistance-associated mutations in the 23S rRNA and parC genes using pyrosequencing and conventional Sanger sequencing, respectively.

Results

In total, 867 M. genitalium positive samples from 2013–2016 were analyzed. Macrolide resistance-associated mutations were detected in 4.6% of the samples from Russia (0.7–6.8% in different cities) and in 10% of the samples from Estonia. The mutations A2059G and A2058G were highly predominating in both Russia and Estonia, accounting together for 90.9% of the cases positive for nucleotide substitutions in the 23S rRNA gene. The rates of possible fluoroquinolone resistance-associated mutations were 6.2% in Russia (2.5–7.6% in different cities) and 5% in Estonia. The mutations S83I and S83N were the most frequent ones in Russia (24.4% each), whereas D87N highly predominated in Estonia (83.3% of all fluoroquinolone resistance-associated mutations). Approximately 1% of the samples in both countries harbored both macrolide and possible fluoroquinolone resistance-associated mutations, with A2058G and S83I being the most frequent combination (37.5%).

Conclusions

The prevalence of macrolide and fluoroquinolone resistance-associated mutations in M. genitalium was 4.6% and 6.2%, respectively, in Russia, and 10% and 5%, respectively, in Estonia. Despite the relatively low rates of macrolide and fluoroquinolone resistance in these countries, antimicrobial resistance surveillance and testing for resistance-associated mutations in M. genitalium positive cases would be valuable.