Macrolide Resistance Mutations Research Articles

Mycoplasma pneumoniae triggers pneumonia epidemic in autumn and winter in Beijing: a multicentre, population-based epidemiological study between 2015 and 2020

ABSTRACT The objective of this paper is to explore the characteristics of Mycoplasma pneumoniae (MP) epidemics in Beijing, China. Patients with acute respiratory tract infection (ARTI) were enrolled from 35 sentinel hospitals in Beijing, 2015–2020. Their medical records were reviewed and respiratory specimens were collected for assay for nucleic acids of 24 respiratory pathogens, including MP. The genotypes of MP were analysed using a real-time PCR method. The domain V of 23s rRNA gene was sequenced to identify macrolide-resistant mutations. A total of 41,677 specimens of ARTI patients were included, with an MP positive rate of 6.16%. MP prevalence mainly occurred between August and January, and peaked in October. The increase in the MP detection rate was coincident with the elevation of the reported number of patients with pneumonia in the 35 sentinel hospitals. One or more respiratory pathogens were co-detected in 27.1% of the MP-positive patients. Type 1 MP remained predominant, and the macrolide-resistant rate of MP had exceeded over 90%. A2063G mutation accounted for 99.0% of macrolide-resistant MP infections. MP epidemic in Beijing mainly occurred between August and January with a remarkable high macrolide-resistant rate. MP is one of the important contributors to the pneumonia epidemic in autumn and winter in Beijing.

2021 European guideline on the management of Mycoplasma genitalium infections.

Asymptomatic infections are frequent. In men, urethritis, dysuria and discharge predominate. In women, symptoms include vaginal discharge, dysuria or symptoms of PID - abdominal pain and dyspareunia. Symptoms are the main indication for diagnostic testing. Diagnosis is achievable only through nucleic acid amplification testing and must include investigation for macrolide resistance mutations. Therapy for M .genitalium is indicated if M. genitalium is detected. Doxycycline has a cure rate of 30-40%, but resistance is not increasing. Azithromycin has a cure rate of 85-95% in macrolide-susceptible infections. An extended course of azithromycin appears to have a higher cure rate, and pre-treatment with doxycycline may decrease organism load and the risk of macrolide resistance selection. Moxifloxacin can be used as second-line therapy but resistance is increasing. Uncomplicated M. genitalium infection without macrolide resistance mutations or resistance testing: Azithromycin 500 mg on day one, then 250 mg on days 2-5 (oral). Second-line treatment and treatment for uncomplicated macrolide-resistant M. genitalium infection: Moxifloxacin 400 mg od for 7 days (oral). Third-line treatment for persistent M. genitalium infection after azithromycin and moxifloxacin: Doxycycline or minocycline 100 mg bid for 14 days (oral) may cure 40-70%. Pristinamycin 1 g qid for 10 days (oral) has a cure rate of around 75%. Complicated M. genitalium infection (PID, epididymitis): Moxifloxacin 400 mg od for 14 days. MAIN CHANGES FROM THE 2016 EUROPEAN M. Due to increasing antimicrobial resistance and warnings against moxifloxacin use, indications for testing and treatment have been narrowed to primarily involve symptomatic patients. The importance of macrolide resistance-guided therapy is emphasised.

Molecular features and antimicrobial susceptibility of Mycoplasma pneumoniae isolates from paediatric inpatients in Weihai, China: Characteristics of M. pneumoniae In Weihai

We analysed the molecular features and antimicrobial susceptibility of Mycoplasma pneumoniae isolates from Weihai, China, in 2019. Pharyngeal swabs of 160 paediatric patients with pneumonia-related symptoms were collected and were subjected to culture and subsequent characteristic analysis. The characteristics of M. pneumoniae isolates were analysed by real-time PCR and genotyping. Antimicrobial susceptibility testing was performed against four antibiotics. All isolates were amplified for analysis of macrolide (ML) resistance mutations in domain V of the 23S rRNA gene and were genotyped using multiple-locus variable-number tandem repeat (VNTR) analysis (MLVA) and 'AGT' VNTR detection in the p1 gene. The M. pneumoniae nucleic acid and culture-positive rate of 160 specimens were 88.1% (141/160) and 51.3% (82/160), respectively. Almost all isolates were ML-resistant (81/82). Point mutation at position 2063 in 23S rRNA was identified in all ML-resistant isolates. The ML resistance rate of M. pneumoniae genotype 2 isolates was 97.6% (41/42). MLVA types 4/5/7/2 and 4/5/7/3 belonged to genotype 1, while type 3/5/6/2 belonged to genotype 2. The numbers of 'AGT' VNTR in the p1 gene from all isolates was in the range of 5-15. This is the first report that the two genotypes of M. pneumoniae were present in a relatively equivalent ratio, with genotype 2 slightly predominant, in paediatric patients in Weihai in 2019, and the overall ML resistance rate was close to 100%. The minimum inhibitory concentration (MIC) of erythromycin in M. pneumoniae with ML resistance mutation A2063T in Weihai was higher than previously reported.

A 3D-Printed Microfluidic Device for qPCR Detection of Macrolide-Resistant Mutations of Mycoplasma pneumoniae.

Mycoplasma pneumonia (MP) is a common respiratory infection generally treated with macrolides, but resistance mutations against macrolides are often detected in mycoplasma pneumoniae in China. Rapid and accurate identification of mycoplasma pneumoniae and its mutant type is necessary for precise medication. This paper presents a 3D-printed microfluidic device to achieve this. By 3D printing, the stereoscopic structures such as microvalves, reservoirs, drainage tubes, and connectors were fabricated in one step. The device integrated commercial polymerase chain reaction (PCR) tubes as PCR chambers. The detection was a sample-to-answer procedure. First, the sample, a PCR mix, and mineral oil were respectively added to the reservoirs on the device. Next, the device automatically mixed the sample with the PCR mix and evenly dispensed the mixed solution and mineral oil into the PCR chambers, which were preloaded with the specified primers and probes. Subsequently, quantitative real-time PCR (qPCR) was carried out with the homemade instrument. Within 80 min, mycoplasma pneumoniae and its mutation type in the clinical samples were determined, which was verified by DNA sequencing. The easy-to-make and easy-to-use device provides a rapid and integrated detection approach for pathogens and antibiotic resistance mutations, which is urgently needed on the infection scene and in hospital emergency departments.

Genotype and mutation patterns of macrolide resistance genes of Mycoplasma pneumoniae from children with pneumonia in Qingdao, China, in 2019

This study assessed the incidence and resistance of Mycoplasma pneumoniae (MP) in children in Qingdao, China, in 2019. We detected MP infection in 78 pharyngeal swabs from children with pneumonia by qPCR. The RepMP4 element in the P1 adhesin gene, domain V of the 23S rRNA gene, and the L4/L22 ribosomal proteins were amplified by nested PCR. Evolutionary analysis was conducted based on the P1 gene sequence. Resistance mutations in domain V of the 23S rRNA gene and L4/L22 ribosomal proteins were analysed. The incidence of MP infection in children with pneumonia was 59.0% (46/78). The mean duration of MP infection was longer than that of non-MP infection. According to P1 gene sequencing of 21 samples, 12 (57.1%) were type 1 and 9 (42.9%) were type 2. Drug resistance mutations A2063G in domain V of 23S rRNA gene and T508C in L22 were identified from all sequenced MP. However, mutations at positions 2064 and 2617 were not found in this study. C162A mutation appeared in most type 2 samples. A430G mutation appeared in one type 1 sample and in several type 2 samples. T279C mutation in L22 was mostly found in type 2 samples. The incidence of MP infection was 59.0% in children with pneumonia in Qingdao in 2019. Type 1 MP infection was slightly more common than type 2, indicating that the genotype of MP is gradually shifting from type 1 to type 2. Macrolide resistance mutation A2063G could be detected in all sequenced MP.

Macrolide-Resistant Mycoplasma pneumoniae Infections in Children, Ohio, USA.

Emergence of macrolide-resistant Mycoplasma pneumoniae (MRMp) challenges empiric macrolide therapy. Our goal was to determine MRMp rates and define characteristics of children infected with macrolide-sensitive M. pneumoniae (MSMp) versus MRMp in Ohio, USA. We cultured PCR-positive M. pneumoniae specimens and sequenced M. pneumoniae–positive cultures to detect macrolide resistance mutations. We reviewed medical records to compare characteristics of both groups. We identified 14 (2.8%) MRMp and 485 (97.2%) MSMp samples. Patients in these groups had similar demographics and clinical characteristics, but patients with MRMp had longer hospitalizations, were more likely to have received previous macrolides, and were more likely to have switched to alternative antimicrobial drugs. MRMp-infected patients also had ≈5-fold greater odds of pediatric intensive care unit admission. Rates of MRMp infections in children in central Ohio are low, but clinicians should remain aware of the risk for severe illness caused by these pathogens.

Clinical Evaluation of a Novel Point-of-Care Assay To Detect Mycoplasma pneumoniae and Associated Macrolide-Resistant Mutations.

The recent increase in macrolide-resistant Mycoplasma pneumoniae in Asia has become a continuing problem. A point-of-care testing method that can quickly detect M. pneumoniae and macrolide-resistant mutations (MR mutations) is critical for proper antimicrobial use. Smart Gene (Mizuho Medy Co., Ltd., Tosu City, Saga, Japan) is a compact and inexpensive fully automatic gene analyzer that combines amplification with PCR and the quenching probe method to specify the gene and MR mutations simultaneously. We performed a clinical evaluation of this device and its reagents on pediatric patients with suspected M. pneumoniae respiratory infections and evaluated the impact of the assay on antimicrobial selection. Using real-time PCR as a comparison control, the sensitivity of Smart Gene was 97.8% (44/45), its specificity was 93.3% (98/105), and its overall concordance rate was 94.7% (142/150). The overall concordance rate of Smart Gene diagnosis of MR mutations in comparison with sequence analysis was 100% (48/48). The ratio of MR mutations was significantly higher at high-level medical institutions than at a primary medical clinic (P = 0.023), and changes in antibiotic therapy to drugs other than macrolides were significantly more common in patients with MR mutations (P = 0.00024). Smart Gene demonstrated excellent utility in the diagnosis of M. pneumoniae and the selection of appropriate antimicrobials for MR mutations at primary medical institutions, which play a central role in community-acquired pneumonia care. The use of this device may reduce referrals to high-level medical institutions for respiratory infections, thereby reducing the medical and economic burdens on patients.

Clinical evaluation of commercial PCR assays for antimicrobal resistance in Mycoplasma genitalium and estimation of resistance-mediated mutation prevalence in Moscow and Moscow region.

Mycoplasma genitalium is a widespread sexually transmitted infection (STI) with growing rate of antimicrobials resistance. In our study, 137 vaginal and 131 urethral M. genitalium-positive swabs were sequentially collected through the work of Reference Center for STI during 2019. For prevalence evaluation of macrolide-resistance mutations three commercially available kits were used: AmpliSens® M. genitalium-ML/FQ-Resist-FL (Central Research Institute of Epidemiology, Russia), ResistancePlus® MG (SpeeDx, Australia), and S-DiaMGRes™ (Diagenode, Belgium). Macrolide resistance mutations were detected in 16% (43 of 268) of samples. Diagnostic characteristics were evaluated against Sanger sequencing. For AmpliSens® M. genitalium-ML/FQ-Resist-FL specificity was shown to be 100% (CI 95%, 98.4-100), and sensitivity was 90.7% (CI 95%, 77.9-97.4). ResistancePlus® MG specificity was 100% (CI 95%, 98.3-100), and sensitivity was 92.1% (CI 95%, 78.6-98.3). S-DiaMGRes™ specificity was shown to be 88.6% (CI 95%, 83.9-92.4), and sensitivity was 100% (CI 95%, 84.4-100). Mutations of parC gene region were detected in 14.5% (38 of 268) using AmpliSens® M. genitalium-ML/FQ-Resist-FL with further validation by Sanger sequencing. Of studied samples, 6.3% (17 of 268) contained both antimicrobials of class resistance mutations. Prevalence of macrolide-resistant M. genitalium in Moscow was 21.7% (23 of 106) and of fluoroquinolone-resistant M. genitaliuim was 20.8% (22 of 106). In Moscow region, macrolide-resistant M. genitalium were 12.3% (20 of 162) and 9.9% (16 of 162) of fluoroquinolone-resistant M. genitalium. All three kits can be used both for epidemiological monitoring of M. genitalium presence and mutation prevalence estimation. In Moscow, macrolide- and fluoroquinolone-resistant mutant prevalence increased in 3.9 and 2.7 times in 3 years.

Efficiency of the novel quenching-probe PCR method to detect 23S rRNA mutations in children with Mycoplasma pneumoniae infection

An automated rapid molecular diagnostic kit (Smart Gene Myco) was recently developed for individual detection of Mycoplasma pneumoniae (MP) genes. This new testing approach requires no special equipment and skills and can be completed within 50 min. We prospectively evaluated this diagnostic kit, along with other conventional tests, for pneumonia diagnosis in children. Samples from 98 children (50 boys and 48 girls; aged 1–14 years; mean: 4.7 ± 2.1 years; median: 4 years) clinically diagnosed with pneumonia were tested for MP using real-time polymerase chain reaction (RT-PCR) as a reference method. Results from three molecular diagnostic tests, serum anti-MP antibodies, and MP culture were compared to RT-PCR data. Among the 98 children, 38 were positive for MP. All molecular diagnostic results showed complete concordance with the RT-PCR data. The sensitivity of the culture was 64%, whereas the sensitivities of the ImmunoCard Mycoplasma and SERODIA Myco II kits were lower (39% and 29%, respectively). Furthermore, a significant positive correlation was found between MP copy numbers and the culture test sensitivity (r = 0.95, p = 0.048). Macrolide-resistance mutations in the 23S ribosomal RNA gene were detected in 24 of 38 children using Smart Gene Myco based on quenching-probe PCR, which was confirmed by direct sequencing, revealing all mutations as A2063G. This is the first study to evaluate the clinical utility of the Smart Gene Myco kit, demonstrating that it is a fast and reliable method to support timely therapeutic decisions in children with MP pneumonia.

Increased power from conditional bacterial genome-wide association identifies macrolide resistance mutations in Neisseria gonorrhoeae

The emergence of resistance to azithromycin complicates treatment of Neisseria gonorrhoeae, the etiologic agent of gonorrhea. Substantial azithromycin resistance remains unexplained after accounting for known resistance mutations. Bacterial genome-wide association studies (GWAS) can identify novel resistance genes but must control for genetic confounders while maintaining power. Here, we show that compared to single-locus GWAS, conducting GWAS conditioned on known resistance mutations reduces the number of false positives and identifies a G70D mutation in the RplD 50S ribosomal protein L4 as significantly associated with increased azithromycin resistance (p-value = 1.08 × 10−11). We experimentally confirm our GWAS results and demonstrate that RplD G70D and other macrolide binding site mutations are prevalent (present in 5.42% of 4850 isolates) and widespread (identified in 21/65 countries across two decades). Overall, our findings demonstrate the utility of conditional associations for improving the performance of microbial GWAS and advance our understanding of the genetic basis of macrolide resistance.

Macrolide-Resistant Bordetella pertussis, Vietnam, 2016−2017

Macrolide-resistant Bordetella pertussis emerged in Vietnam during 2016−2017. Direct analyses of swab samples from 10 patients with pertussis revealed a macrolide-resistant mutation, A2047G, in the 23S rRNA. We identified the MT104 genotype of macrolide-resistant B. pertussis (which is prevalent in mainland China) and its variants in these patients.

Periodic Genotype Shifts in Clinically Prevalent Mycoplasma pneumoniae Strains in Japan.

Nationwide increases in Mycoplasma pneumoniae pneumonia cases in Japan were reported in 2011, 2012, 2015, and 2016. In this study, we isolated 554 M. pneumoniae strains in 4 areas in Japan (Kanagawa, Okayama, Osaka, and Saitama) between 2006 and 2019, and performed genotyping analysis. More than 80% of the strains isolated in 2011 and 2012 harbored type 1 p1 adhesin gene; however, strains harboring type 2 or its variant p1 gene increased in 2015 and 2016 and dominated after 2017. These findings suggested that a shift in the prevalent genotype of M. pneumoniae clinical strains occurred recently in Japan. More than 90% of the type 1 strains isolated after 2010 harbored macrolide-resistance mutations in their 23S rRNA gene, whereas most type 2 lineage strains had no such mutations. Consequently, the increase in type 2 lineage strains in Japan has reduced the macrolide resistance rate of clinical M. pneumoniae strains. During this analysis, we also identified M. pneumoniae strains carrying a novel variant type 1 p1 gene, and we classified it as type 1b. We then sequenced the genomes of 81 selected M. pneumoniae strains that we collected between 1976 and 2017 in Japan, and compared them with 156 M. pneumoniae genomes deposited in public databases to provide insights into the interpretation of M. pneumoniae genotyping methods, including p1 typing, multiple-locus variable-number tandem repeat analysis (MLVA), multi-locus sequence typing (MLST), and typing by 8 single-nucleotide polymorphism markers (SNP-8). As expected, p1 typing, MLST, and SNP-8 results exhibited good correlation with whole-genome SNP analysis results in terms of phylogenetic relationships; however, MLVA typing results were less comparable to those of the other methods. MLVA may be useful for the discrimination of strains derived from a single outbreak within a limited area; however, is not reliable for classification of strains collected from distantly separated areas at different time points. This study showed the usefulness of genome-based comparison of M. pneumoniae for molecular epidemiology. Genome sequencing of more strains will improve our understanding of global propagation routes of this pathogen and evolutionary aspects of M. pneumoniae strains.

Understanding the spread of de novo and transmitted macrolide-resistance in Mycoplasma genitalium.

BackgroundThe rapid spread of azithromycin resistance in sexually transmitted Mycoplasma genitalium infections is a growing concern. It is not yet clear to what degree macrolide resistance in M. genitalium results from the emergence of de novo mutations or the transmission of resistant strains.MethodsWe developed a compartmental transmission model to investigate the contribution of de novo macrolide resistance mutations to the spread of antimicrobial-resistant M. genitalium. We fitted the model to resistance data from France, Denmark and Sweden, estimated the time point of azithromycin introduction and the rates at which infected individuals receive treatment, and projected the future spread of resistance.ResultsThe high probability of de novo resistance in M. genitalium accelerates the early spread of antimicrobial resistance. The relative contribution of de novo resistance subsequently decreases, and the spread of resistant infections in France, Denmark and Sweden is now mainly driven by transmitted resistance. If treatment with single-dose azithromycin continues at current rates, macrolide-resistant M. genitalium infections will reach 25% (95% confidence interval, CI [9–30]%) in France, 84% (95% CI [36–98]%) in Denmark and 62% (95% CI [48–76]%) in Sweden by 2025.ConclusionsBlind treatment of urethritis with single-dose azithromycin continues to select for the spread of macrolide resistant M. genitalium. Clinical management strategies for M. genitalium should limit the unnecessary use of macrolides.

Quinolone Resistance–Associated Mutations in Mycoplasma genitalium: Not Ready for Prime Time

Quinolone Resistance–Associated Mutations in Mycoplasma genitalium: Not Ready for Prime Time

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

A prospective cross-sectional analysis was conducted of rectally asymptomatic MSM having a rectal swab collected as part of their routine care. Participants self-collected a rectal swab to be tested for M. genitalium and completed a 14-item questionnaire that provided information on behavioural risk factors. The prevalence of rectal M. genitalium was determined and multivariate analysis was performed to assess the associations for this infection. Positive specimens then underwent testing for macrolide-resistant mutations (MRMs) using the ResistancePlus MG assay (SpeeDx, Eveleigh, NSW, Australia). In all, 742 patients were consecutively enrolled in the study. The median age was 31 years (interquartile range 27-39 years), with 43.0% born in Australia. Overall, 19.0% of men were bisexual, 22.9% were taking pre-exposure prophylaxis (PrEP) and 4.3% were HIV positive. The prevalence of rectal M. genitalium was 7.0% (95% confidence interval (CI) 5.3-9.1) overall and 11.8% in those taking PrEP. On multivariate analysis, PrEP use was significantly associated with having rectal M. genitalium (odds ratio 2.01; 95% CI 1.09-3.73; P = 0.01). MRMs were detected in 75.0% (36/48; 95% CI 60.4-86.4%) of infections. Rates of rectal M. genitalium infection were high among asymptomatic MSM attending SSHC and MRMs were detected in 75% of infections. PrEP use was found to be significantly associated with rectal M. genitalium infection. These data contribute to the evidence base for screening guidelines in MSM.

Barriers to testing and management of Mycoplasma genitalium infections in primary care.

Testing and treatment for Mycoplasma genitalium (MG) infections has recently been facilitated by the increasing availability of molecular tests, but the role of testing in community-based populations is not established. Between 15 May 2017 and 22 November 2017, we tested 561 samples from 547 individuals presenting to primary care in Auckland, New Zealand, requesting investigation for sexually transmitted infections, with concurrent sterile pyuria, using the Aptima MG assay (Hologic, San Diego, CA, USA) in order to establish the prevalence of MG in this group, rates of macrolide resistance and audit primary care’s capacity to manage infections in line with international guidelines. MG was detected in 55 (10%) samples, and co-pathogens were detected in 24 (44%) MG-positive samples. Macrolide resistance mutations were detected in 22/36 (61%) samples subsequently tested using PlexPCR M. genitalium ResistancePlus (Speedx Pvt Ltd., Sydney, Australia). Empiric azithromycin treatment was given to 18 (33%) patients, and test of cure was performed in 15 (27%) patients. Our pilot study demonstrates that sterile pyuria can be a useful marker to direct testing resources in community settings, but highlights important barriers to management of MG in primary care, including clinician knowledge, high prevalence of macrolide resistance and poor completion rates for test of cure.

Enhanced molecular typing and macrolide and tetracycline-resistance mutations of Treponema pallidum in Barcelona.

Aim: To describe the molecular types of Treponema pallidum and the proportion of macrolide and tetracycline resistance mutations in Barcelona. Materials & methods: Molecular type was determined using the Enhanced-CDC Typing system and antibiotic resistance was determined by sequencing the 23S and 16S rRNA genes. Results: A total of 183 patients were enrolled and 213 specimens (99 ulcers, 114 bloods) were collected. Sixty-two (70.5%) of 88 ulcers and 0 (0%) of bloods T. pallidum-DNA containing samples were fully typed. Up to 21 different strain types were identified (14d/g in 27.4%; 14f/g in 14.5%). Macrolide resistance mutations were present in 95% and tetracycline in 0%. Conclusion: Several different strains co-exist in Barcelona with a high proportion of macrolide resistance and absence of tetracycline resistance.

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

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

Lack of Association Between the S83I ParC Mutation in Mycoplasma genitalium and Treatment Outcomes Among Men Who Have Sex With Men with Nongonococcal Urethritis.

From February 2015 to October 2017, among 20 men who have sex with men with Mycoplasma genitalium-associated nongonococcal urethritis, 15% had macrolide resistance and S83I ParC mutations. Azithromycin followed by moxifloxacin cleared Mycoplasma genitalium in 2 of 2 with and 11 of 13 without S83I mutations. Dual failures were cleared after doxycycline. S83I mutations were not associated with moxifloxacin failure.

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

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