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

Mycoplasma genitalium Infections Among Participants in an HIV Pre-exposure Prophylaxis Program in Hanoi, Vietnam

BACKGROUND

Mycoplasma genitalium causes a sexually transmitted infection and is also emerging as an important antimicrobial resistant pathogen. Data on M. genitalium infections among men who have sex with men (MSM) in low-resource settings are sparse.

METHODS

From January to December 2022, participants in an HIV pre-exposure prophylaxis (PrEP) program in Hanoi, Vietnam were enrolled into the study. Demographic, behavioral, and clinical characteristics were collected. Self-collected urine, rectal, and pharyngeal specimens were tested for M. genitalium using the Alinity m STI Assay (Abbott Molecular, USA). Univariate and multivariate logistic regression were performed to assess for factors associated with infections.

RESULTS

Among 477 participants, the median age was 25.3 years (21.7-29.6) and 92.2% (n = 440) identified as MSM; 48.6% had ≥2 sex partners and 38.1% reported condomless anal sex in the prior month. The overall prevalence of M. genitalium infection was 10.9% (52/477); 7.3% (34/464) rectal, 3.2% (15/476) urethral, and 1.9% (9/476) pharyngeal. Infections were asymptomatic in 71.2% (37/52). Among those with M. genitalium , 30.7% (16/52) were co-infected with either Neisseria gonorrhoeae or Chlamydia trachomatis. Among those reporting rectal (n = 51) or urethral (n = 35) symptoms, but without C. trachomatis or N. gonorrhoeae co-infections, five (9.8%) had rectal infections and one (2.9%) had urethral infection. Participants with M. genitalium were more likely to be asymptomatic than participants without M. genitalium (adjusted odds ratio, 1.93; 95% confidence interval, 1.01-3.71).

CONCLUSIONS

Mycoplasma genitalium infections were common among primarily MSM engaged in an HIV PrEP program in Vietnam. The prevalence was highest in rectal specimens and nearly three quarters of M. genitalium infections were asymptomatic. Testing for M. genitalium infections among those with symptoms is important to enable pathogen-directed therapy. Additional research on antimicrobial resistance and treatment strategies for M. genitalium in low-resource settings is needed.

Mycoplasma genitalium infection and resistance-associated mutations to macrolides and fluoroquinolones among high-risk patients in Taiwan

BACKGROUND

Mycoplasma genitalium is an emerging etiology of sexually transmitted infections (STIs) with increasing resistance to antimicrobials. Surveillance on the epidemiology of M. genitalium infection and antimicrobial resistance is warranted.

METHODS

Between September 2021 and August 2023, people with HIV (PWH) and people without HIV (PWoH) at risk of STIs were screened for M. genitalium infection using a multiplex polymerase-chain-reaction assay of specimens collected from the rectum, urethra, oral cavity, and vagina. The prevalences of resistance-associated mutations (RAMs) of M. genitalium to fluoroquinolones, macrolides, and tetracycline were investigated.

RESULTS

During the 2-year study period, 1021 participants were enrolled, including 531 PWH and 490 PWoH. Overall, 83 (8.1%) and 34 (7.6%) participants had M. genitalium infection at baseline and during follow-up, respectively, with the rectum being the most common site of detection (61.5%). With the first course of antimicrobial treatment, 27 of 63 (42.9%) participants with M. genitalium infection were cured during follow-up, including 24 of 58 (41.4%) who received doxycycline monotherapy. The prevalence of RAMs to macrolides, fluoroquinolones, and tetracyclines at baseline were 24.3%, 22.4%, and 7.9%, respectively. Though PWH had more M. genitalium infection (10.2% vs 5.9%, p = 0.01), a higher rate of RAMs to macrolides (41.0% vs 14.7%, p < 0.01) was found in PWoH.

CONCLUSIONS

Among high-risk populations, the prevalence of M. genitalium infection was 8.1%. The overall genotypic resistance of M. genitalium to macrolides and fluoroquinolones was moderately high in Taiwan. Detection of M. genitalium infection and antimicrobial resistance is warranted to ensure resistance-guided antimicrobial treatments to be administered.

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.

Potential therapeutic targets for combating Mycoplasma genitalium

Mycoplasma genitalium (M. genitalium) has emerged as a sexually transmitted infection (STI) all over the world in the last three decades. It has been identified as a cause of male urethritis, and there is now evidence that it also causes cervicitis and pelvic inflammatory disease in women. However, the precise role of M. genitalium in diseases such as pelvic inflammatory disease, and infertility is unknown, and more research is required. It is a slow-growing organism, and with the advent of the nucleic acid amplification test (NAAT), more studies are being conducted and knowledge about the pathogenicity of this organism is being elucidated. The accumulation of data has improved our understanding of the pathogen and its role in disease transmission. Despite the widespread use of single-dose azithromycin in the sexual health field, M. genitalium is known to rapidly develop antibiotic resistance. As a result, the media frequently refer to this pathogen as the "new STI superbug." Despite their rarity, antibiotics available today have serious side effects. As the cure rates for first-line antimicrobials have decreased, it is now a challenge to determine the effective antimicrobial therapy. In this review, we summarise recent M. genitalium research and investigate potential therapeutic targets for combating this pathogen.

Evaluation of Clinical, Gram Stain, and Microbiological Cure Outcomes in Men Receiving Azithromycin for Acute Nongonococcal Urethritis: Discordant Cures Are Associated With Mycoplasma genitalium Infection

BACKGROUND

In men with nongonococcal urethritis (NGU), clinicians and patients rely on clinical cure to guide the need for additional testing/treatment and when to resume sex, respectively; however, discordant clinical and microbiological cure outcomes do occur. How accurately clinical cure reflects microbiological cure in specific sexually transmitted infections (STIs) is unclear.

METHODS

Men with NGU were tested for Neisseria gonorrhoeae, Chlamydia trachomatis (CT), Mycoplasma genitalium (MG), Trichomonas vaginalis, urethrotropic Neisseria meningitidis ST-11 clade strains, and Ureaplasma urealyticum (UU). Men received azithromycin 1 g and returned for a 1-month test-of-cure visit. In MG infections, we evaluated for the presence of macrolide resistance-mediating mutations (MRMs) and investigated alternate hypotheses for microbiological treatment failure using in situ shotgun metagenomic sequencing, phylogenetic analysis, multilocus sequence typing analyses, and quantitative PCR.

RESULTS

Of 280 men with NGU, 121 were included in this analysis. In the monoinfection group, 52 had CT, 16 had MG, 7 had UU, 10 had mixed infection, and 36 men had idiopathic NGU. Clinical cure rates were 85% for CT, 100% for UU, 50% for MG, and 67% for idiopathic NGU. Clinical cure accurately predicted microbiological cure for all STIs, except MG. Discordant results were significantly associated with MG-NGU and predominantly reflected microbiological failure in men with clinical cure. Mycoplasma genitalium MRMs, but not MG load or strain, were strongly associated with microbiological failure.

CONCLUSIONS

In azithromycin-treated NGU, clinical cure predicts microbiological cure for all STIs, except MG. Nongonococcal urethritis management should include MG testing and confirmation of microbiological cure in azithromycin-treated MG-NGU when MRM testing is unavailable.

Burden of Mycoplasma genitalium and Bacterial Coinfections in a Population-Based Sample in New Mexico

ABSTRACT

In this population-based US study, the overall prevalence of Mycoplasma genitalium was 1.95% (95% confidence interval [CI], 1.62%-2.34%), declining from 6.12% (95% CI, 4.72%-7.92%) in women aged 21 to 24 years to 0.48% (95% CI, 0.25%-0.94%) in women aged 40 to 64 years. The prevalence of coinfections with Chlamydia trachomatis and Trichomonas vaginalis was low.

Azithromycin and Doxycycline Resistance Profiles of U.S. Mycoplasma genitalium Strains and Their Association with Treatment Outcomes

Mycoplasma genitalium is a sexually transmitted bacterium associated with nongonococcal urethritis (NGU) in men and cervicitis, endometritis, and pelvic inflammatory disease in women. Effective treatment is challenging due to the inherent, and increasingly acquired, antibiotic resistance in this pathogen. In our treatment trial conducted from 2007 to 2011 in Seattle, WA, we demonstrated poor efficacy of azithromycin (AZM) and doxycycline (DOX) against M. genitalium among men with NGU. In the present study, we cultured M. genitalium from 74 of 80 (92.5%) PCR-positive men at enrollment (V-1) and defined the MICs of AZM (N = 56 isolates) of DOX (N = 62 isolates). Susceptibility to AZM was bimodal; MICs were >8 μg/ml (44.6%) and <0.004 μg/ml (55.4%) for these isolates. The association of MIC with treatment efficacy was determined for men initially treated with either AZM (N = 30) or DOX (N = 24). Men treated with AZM were more likely to experience microbiologic treatment failure (P < 0.001) if infected with isolates that had AZM MICs of >8 μg/ml (18/18 men) than those with isolates that had AZM MICs of <0.004 μg/ml (1/12 men). Clinical treatment failure also was more likely to occur (P = 0.002) with AZM MICs of >8 μg/ml (12/18 men) than with AZM MICs of <0.004 μg/ml (1/12 men). In contrast, DOX MICs ranged from <0.125 to 2 μg/ml and were not correlated with microbiologic (P = 0.71) or clinical treatment (P = 0.41) failure, demonstrating no relationship between DOX MICs and treatment efficacy. Given the rapid spread of AZM resistance and the emergence of quinolone resistance, the current second-line therapy, monitoring MICs and evaluating other potential treatments for M. genitalium will be critical.

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.

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.

Targeting COVID-19 in Parkinson's Patients: Drugs Repurposed

The last couple of months have witnessed the world in a state of virtual standstill. The SARS-CoV-2 virus has overtaken the globe to economic and social lockdown. Many patients with COVID-19 have compromised immunity, especially in an aged population suffering from Parkinson 's disease (PD). Alteration in dopaminergic neurons and deficiency of dopamine in PD patients are the most common symptoms affecting 1% population above the age of 60 years. The compromised immune system and inflammatory manifestation in PD patients make them an easy target. The most common drugs under trial for COVID-19 are remdesivir, favipiravir, chloroquine and hydroxychloroquine, azithromycin along with adjunct drugs like amantadine with some monoclonal antibodies. Presently, clinically US FDA approved drugs in PD include Levodopa, catechol-O-methyl transferase (COMT) inhibitors, (Entacapone and Tolcapone), dopamine agonists (Bromocriptine, Ropinirole, Pramipexole, and Rotigotine), monoamine oxidase B (MAO-B) inhibitors (Selegiline and Rasagiline), amantadine and antimuscarinic drugs. The drugs have established mechanisms of action on PD patients with known pharmacodynamics and pharmacokinetic properties along with dose and adverse effects. Conclusion and relevance of this review focus on the drugs that can be tried on PD patients with SAR CoV-2 infection, in particular, amantadine that has been approved by all the developed countries as a common drug possessing both antiviral properties by downregulation of CTSL, lysosomal pathway disturbance and change in pH necessary to uncoat the viral proteins and anti- Parkinson properties. To deal with the significant prognostic adverse effect of SARS-CoV-2 on PD, the present-day treatment options, clinical presentation and various mechanisms are the need of the hour.

Incidence of Nongonococcal Urethritis in Men Who Have Sex With Women and Associated Risk Factors

BACKGROUND

Incidence and risk factors for nongonococcal urethritis (NGU) remain poorly defined. We conducted a cohort study to estimate the incidence of NGU and identify risk factors in men who have sex with women.

METHODS

We enrolled cisgender male sexually transmitted disease clinic attendees 16 years or older who reported exclusively female partners. At enrollment and 6 monthly follow-up visits, men underwent a clinical examination, provided urethral swab and urine specimens, completed a sexual behavior survey and biweekly diaries, and were tested for Chlamydia trachomatis (CT) and Mycoplasma genitalium (MG) using Aptima assays (Hologic, Inc). Nongonococcal urethritis was defined as ≥5 polymorphonuclear leukocytes per high-power field plus either urethral symptoms or visible discharge. We estimated the incidence of NGU overall, asymptomatic and symptomatic NGU, non-CT/non-MG NGU, and CT/MG-associated NGU using Poisson regression for clustered outcomes. We performed relative risk binomial regression for clustered data to identify characteristics associated with incident NGU.

RESULTS

From August 2014 to July 2018, 307 participants at risk for NGU contributed 109.4 person-years. Median age was 32 years, and 52% were White. At enrollment, 107 men had NGU; of these, 88% were symptomatic, 27% had CT, and 22% had MG. Fifty men had 60 cases of incident NGU (incidence rate, 56 per 100 person-years; 95% confidence interval, 43-74). Unlike prevalent NGU at enrollment, CT/MG-associated incident NGU was rare (incidence rate, 7; 95% confidence interval [CI], 4-15), and most (78%) incident NGU was asymptomatic. Risk factors for incident NGU were ≤ high school education (adjusted rate ratio [ARR], 2.45; 95% CI, 1.19-5.00), history of CT (ARR, 2.15; 95% CI, 1.08-4.27), history of NGU (ARR, 2.67; 95% CI, 1.27-5.62), and NGU at enrollment (ARR, 2.03; 95% CI, 1.04-3.98). Neither condom use nor having a new partner was associated with incident NGU; Black race was only associated with incident symptomatic and non-CT/non-MG NGU.

CONCLUSIONS

Incidence of NGU was high, predominantly non-CT/non-MG and asymptomatic. Future studies should investigate the etiology and clinical significance of asymptomatic NGU.

Resistance-guided treatment of Mycoplasma genitalium infection at a UK sexual health centre

We evaluated the ResistancePlus® MG assay in providing macrolide resistance-guided treatment (RGT) for Mycoplasma genitalium infection at a UK sexual health centre. M. genitalium-positive samples from men with urethritis and women with pelvic inflammatory disease (PID) were tested for macrolide resistance-mediating mutations (MRMMs). MRMM-positive infections were given moxifloxacin 400 mg; otherwise 2 g azithromycin (1 g single dose and then 500 mg OD) was given. Among 57 M. genitalium-positive patients (32 men and 25 women), MRMMs were detected in 41/57 (72% [95% confidence interval (95% CI) 58-83%). Thirty-two of 43 patients given RGT attended for test of cure. Treatment failure rate was significantly lower at 1/32 (3%) than 10/37 (27%) before RGT (n = 37 [men = 23 and women = 17]; p = 0.008). Treatment failure was lower in male urethritis (0/15 vs. 7/21 p = 0.027) but not in female PID. There was a trend of a shorter time to negative test of cure (TOC) in male urethritis (55.1 [95% 43.7-66.4] vs. 85.1 [95% CI CI 64.1-106.0] days, p = 0.077) but not in female PID. Macrolide resistance is higher than previous UK reports and higher than expected. RGT reduces overall treatment failure and is particularly beneficial in M. genitalium urethritis. Fluoroquinolone resistance will continue to rise with increasing fluoroquinolone use, and RGT is critical to direct appropriate azithromycin use and prevent overuse of moxifloxacin.

Sequence variation and immunogenicity of the Mycoplasma genitalium MgpB and MgpC adherence proteins during persistent infection of men with non-gonococcal urethritis

Mycoplasma genitalium is a sexually transmitted bacterial pathogen that infects men and women. Antigenic variation of MgpB and MgpC, the immunodominant adherence proteins of M. genitalium, is thought to contribute to immune evasion and chronic infection. We investigated the evolution of mgpB and mgpC sequences in men with non-gonococcal urethritis persistently infected with M. genitalium, including two men with anti-M. genitalium antibodies at enrollment and two that developed antibodies during follow-up. Each of the four patients was persistently infected with a different strain type and each patient produced antibodies targeting MgpB and MgpC. Amino acid sequence evolution in the variable regions of MgpB and MgpC occurred in all four patients with changes observed in single and multiple variable regions over time. Using the available crystal structure of MgpC of the G37 type strain we found that predicted conformational B cell epitopes localize predominantly to the variable region of MgpC, amino acids that changed during patient infection lie in these epitopes, and variant amino acids are in close proximity to the conserved sialic acid binding pocket. These findings support the hypothesis that sequence variation functions to avoid specific antibodies thereby contributing to persistence in the genital tract.

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 Detection in Urogenital Specimens from Symptomatic and Asymptomatic Men and Women by Use of the cobas TV/MG Test

Mycoplasma genitalium (MG) infections are a growing concern within the field of sexually transmitted infections. However, diagnostic assays for M. genitalium have been limited in the United States. As most infections are asymptomatic, individuals can unknowingly pass the infection on, and the prevalence is likely to be underestimated. Diagnosis of M. genitalium infection is recommended using a nucleic acid test. This multicenter study assessed the performance of the cobas Trichomonas vaginalis (TV)/MG assay (cobas) for the detection of M. genitalium, using 22,150 urogenital specimens from both symptomatic and asymptomatic men and women collected at geographically diverse sites across the United States.

Mycoplasma genitalium (MG) infections are a growing concern within the field of sexually transmitted infections. However, diagnostic assays for M. genitalium have been limited in the United States. As most infections are asymptomatic, individuals can unknowingly pass the infection on, and the prevalence is likely to be underestimated. Diagnosis of M. genitalium infection is recommended using a nucleic acid test. This multicenter study assessed the performance of the cobas Trichomonas vaginalis (TV)/MG assay (cobas) for the detection of M. genitalium, using 22,150 urogenital specimens from both symptomatic and asymptomatic men and women collected at geographically diverse sites across the United States. The performance was compared to a reference standard of three laboratory-developed tests (LDTs). The specificity of the cobas assay for M. genitalium ranged from 96.0% to 99.8% across symptomatic and asymptomatic men and women. The sensitivities in female vaginal swabs and urine samples were 96.6% (95% confidence interval [CI], 88.5 to 99.1%) and 86.4% (95% CI, 75.5 to 93.0%), respectively. The sensitivities in male urine and meatal swab samples were 100% (95% CI, 94.0 to 100%) and 85.0% (95% CI, 73.9 to 91.9%), respectively. This study demonstrated that the cobas assay was highly sensitive and specific in all relevant clinical samples for the detection of M. genitalium.

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.

Design and Validation of Transcription-Mediated-Amplification Nucleic Acid Amplification Tests for Mycoplasma genitalium

Mycoplasma genitalium is a sexually transmitted bacterium linked to adverse sexual and reproductive health outcomes in women and men. M. genitalium is difficult to culture, and in the absence of validated amplified molecular methods for diagnosis of infection, there is no reference standard available for use as a comparator for the validation of new M. genitalium diagnostic tests. We evaluated the analytical and clinical performance of three transcription-mediated amplification (TMA) tests for M. genitalium, each targeting unique rRNA sequences, for use as a composite comparator for clinical validation of the Aptima Mycoplasma genitalium (AMG) assay, an in vitro diagnostic (IVD) TMA test that targets 16 s rRNA of M. genitalium Analytical sensitivity, specificity, and strain inclusivity of all four TMA tests were determined using nine laboratory strains of M. genitalium and 56 nontarget bacteria, protozoa, and viruses. Analytical sensitivity of the tests for M. genitalium ranged from 0.017 to 0.040 genome equivalents/ml. None of the nontarget organisms evaluated cross-reacted with any test. A composite comparator reference standard consisting of the 3 alternate (Alt) TMA tests was used to evaluate the clinical performance of the AMG assay by testing residual vaginal swab, female urine, and male urine specimens obtained from 1,400 adult subjects from three U.S. clinical sites. Using this reference standard to establish infected specimen status, the sensitivity, specificity, and overall agreement of the AMG IVD assay were 100%, 99.9%, and 99.9%, respectively. These results demonstrate the utility of molecular composite reference standard methodology for the clinical validation of future IVD tests for this organism.