Combination Therapy for Mycoplasma genitalium, and New Insights Into the Utility of parC Mutant Detection to Improve Cure.

BACKGROUND: Mycoplasma genitalium (MG) infection is challenging to cure because of rising antimicrobial resistance and limited treatment options. METHODS: This was a prospective evaluation of the efficacy and tolerability of resistance-guided combination antimicrobial therapy for MG treatment at Melbourne Sexual Health Centre (August 2019-December 2020). All patients received 7 days of doxycycline before combination therapy based on the macrolide-resistant profile. Macrolide-susceptible infections received combination doxycycline + azithromycin (1 g, day 1; 500 mg, days 2-4) and macrolide-resistant infections combination doxycycline + moxifloxacin (400 mg daily for 7 days). Adherence and adverse effects were recorded at test-of-cure, recommended 14-28 days after antimicrobial completion. Sequencing was performed to determine the prevalence of single nucleotide polymorphisms (SNPs) in the parC gene and their association with moxifloxacin treatment outcomes in macrolide-resistant infections. RESULTS: Of 100 patients with macrolide-susceptible MG treated with doxycycline + azithromycin, 93 were cured (93.0%; 95% confidence interval [CI], 86.1-97.1). Of 247 patients with macrolide-resistant MG receiving doxycycline + moxifloxacin, 210 were cured (85.0%; 95% CI, 80.0-89.2). parC sequencing was available for 164 (66%) macrolide-resistant infections; 29% had SNPs at parC S83 or D87 (23% S83I). The absence of SNPs at parC S83/D87 was associated with 98.3% cure (95% CI, 93.9-99.8) following doxycycline + moxifloxacin. The presence of the parC S83I-SNP was associated with failure in 62.5% (95% CI, 45.8-77.3). Side effects were common (40%-46%) and predominantly mild and gastrointestinal. CONCLUSIONS: Combination doxycycline + azithromycin achieved high cure for macrolide-susceptible infections. However, in the context of a high prevalence of the parC S83I mutation (23%) in macrolide-resistant infections, doxycycline + moxifloxacin cured only 85%. Infections that were wild-type for S83/D87 experienced high cure following doxycycline + moxifloxacin, supporting the use of a parC-resistance/susceptibility testing strategy in clinical care.

Phenotypic and genotypic antimicrobial susceptibility patterns of the emerging human respiratory pathogen Mycoplasma amphoriforme isolated from the UK and Denmark.

OBJECTIVES: To determine the phenotypic and genotypic antibiotic susceptibility of Mycoplasma amphoriforme isolates recovered from patients in the UK and Denmark. METHODS: Seven isolates of M. amphoriforme were examined for antimicrobial susceptibility to seven antibiotics using the microbroth dilution assay in line with the CLSI guidelines for mycoplasmas. Each isolate was additionally subjected to WGS to identify resistance-associated mutations. Based on the consensus sequences from the genomic data, PCR primers were designed, and tested, for the amplification of the QRDR within the parC gene. RESULTS: Of the seven isolates investigated, four (57%) were resistant to moxifloxacin (0.5-1 mg/L) and levofloxacin (1-2 mg/L), compared with those that were susceptible (0.03-0.06 and 0.006 mg/L, respectively). Isolate H29 was resistant to five of the seven antibiotics tested: moxifloxacin, 0.5 mg/L; levofloxacin, 2 mg/L; azithromycin, 64 mg/L; erythromycin, 128 mg/L; and clindamycin, 64 mg/L. All isolates were susceptible to tetracycline (0.06 mg/L) and lefamulin (0.001-0.004 mg/L). Mutations from genomic data confirmed the presence of an S89F mutation within the ParC protein among all fluoroquinolone-resistant isolates and an A2059G mutation in the 23S rRNA gene in the macrolide- and lincosamide-resistant isolate H29. CONCLUSIONS: To the best of our knowledge, this is the first time where phenotypic and genotypic resistance data have been paired for M. amphoriforme confirming a correlation between the two. These data suggest the need for focused testing and resistance determination of isolates from high-risk patients given the backdrop of a high prevalence of antimicrobial resistance.

A Nationwide Observational Study of Chlamydia trachomatis Infections in Denmark during the COVID-19 Pandemic.

The aim of this study was to determine whether COVID-19 restrictions had an impact on Chlamydia trachomatis infections compared with 2018 and 2019. A retrospective nationwide observational study was performed using monthly incidences of laboratory-confirmed chlamydia cases and number of tests, obtained from Danish national surveillance data. Testing rates and positivity rates were compared using Poisson and logistic regression. The first Danish COVID-19 lockdown (12 March to 14 April 2020) resulted in a reduction in the number of chlamydia tests performed (rate ratio 0.72, 95% confidence interval  0.71-0.73) and a consequent reduction in the number of laboratory-identified cases (66.5 vs 88.3 per 100,000 population during the same period in 2018 to 2019). This period was followed by a return of testing and test positivity close to the level seen in 2018 to 2019. The second Danish COVID-19 lockdown (17 December to 31 March 2021) resulted in crude incidence rates of laboratory-confirmed chlamydia infection that were similar to the crude incidence rates seen during same period in 2018 to 2019. In conclusion, the Danish COVID-19 restrictions have had negligible effects on laboratory-confirmed C. trachomatis transmission.

Fatal 3-Nitropropionic Acid Poisoning after Consuming Coconut Water.

We describe the fatal course of a patient with initial symptoms of vomiting and nausea who developed symptoms of dystonia, encephalopathy, and coma. The cause of death was poisoning with 3-nitropropionic acid from coconut water spoiled with the fungus Arthrinium saccharicola. We present the clinical findings and forensic analysis.

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.

Moxifloxacin and Sitafloxacin Treatment Failure in Mycoplasma genitalium Infection: Association with parC Mutation G248T (S83I) and Concurrent gyrA Mutations.

BACKGROUND: The basis of fluoroquinolone treatment failure for Mycoplasma genitalium is poorly understood. METHODS: To identify mutations associated with failure we sequenced key regions of the M. genitalium parC and gyrA genes for patients undergoing sequential therapy with doxycycline-moxifloxacin (201 patients, including 21 with failure) or doxycycline-sitafloxacin (126 patients, including 13 with failure). RESULTS: The parC G248T/S83I mutation was more common among patients with failed sequential doxycycline-moxifloxacin (present in 76.2% of failures vs 7.8% cures, P < .001) or doxycycline-sitafloxacin (50% vs 16.8%, respectively; P = .01) treatment. Doxycycline-sitafloxacin was more efficacious than doxycycline-moxifloxacin against infections carrying the parC mutation conferring S83I amino acid change. Treatment was more likely to fail in these infections if they had a concurrent gyrA mutation (M95I or D99N) (P = .07 for doxycycline-moxifloxacin group and P = .009 for doxycycline-sitafloxacin group), suggesting an additive effect. CONCLUSIONS: This study indicates that parC G248T/S83I mutations contribute to failure of moxifloxacin and sitafloxacin, and the findings will inform the development of quinolone resistance assays needed to ensure optimal selection of antimicrobials for M. genitalium.

Genomic evolution of Neisseria gonorrhoeae since the preantibiotic era (1928-2013): antimicrobial use/misuse selects for resistance and drives evolution.

BACKGROUND: Multidrug-resistant Neisseria gonorrhoeae strains are prevalent, threatening gonorrhoea treatment globally, and understanding of emergence, evolution, and spread of antimicrobial resistance (AMR) in gonococci remains limited. We describe the genomic evolution of gonococci and their AMR, related to the introduction of antimicrobial therapies, examining isolates from 1928 (preantibiotic era) to 2013 in Denmark. This is, to our knowledge, the oldest gonococcal collection globally. METHODS: Lyophilised isolates were revived and examined using Etest (18 antimicrobials) and whole-genome sequencing (WGS). Quality-assured genome sequences were obtained for 191 viable and 40 non-viable isolates and analysed with multiple phylogenomic approaches. RESULTS: Gonococcal AMR, including an accumulation of multiple AMR determinants, started to emerge particularly in the 1950s-1970s. By the twenty-first century, resistance to most antimicrobials was common. Despite that some AMR determinants affect many physiological functions and fitness, AMR determinants were mainly selected by the use/misuse of gonorrhoea therapeutic antimicrobials. Most AMR developed in strains belonging to one multidrug-resistant (MDR) clade with close to three times higher genomic mutation rate. Modern N. gonorrhoeae was inferred to have emerged in the late-1500s and its genome became increasingly conserved over time. CONCLUSIONS: WGS of gonococci from 1928 to 2013 showed that no AMR determinants, except penB, were in detectable frequency before the introduction of gonorrhoea therapeutic antimicrobials. The modern gonococcus is substantially younger than previously hypothesized and has been evolving into a more clonal species, driven by the use/misuse of antimicrobials. The MDR gonococcal clade should be further investigated for early detection of strains with predispositions to develop and maintain MDR and for initiation of public health interventions.

Doxycycline and Sitafloxacin Combination Therapy for Treating Highly Resistant Mycoplasma genitalium.

Antimicrobial-resistant Mycoplasma genitalium is becoming increasingly common and creating major treatment challenges. We present early data on combination therapy with doxycycline and sitafloxacin to treat highly resistant M. genitalium. We found the regimen was well tolerated and cured 11/12 infections that had failed prior regimens with moxifloxacin and pristinamycin.

Single-Locus-Sequence-Based Typing of the mgpB Gene Reveals Transmission Dynamics in Mycoplasma genitalium.

Sexually transmitted infections (STIs) by Mycoplasma genitalium are a major problem worldwide, especially given their marked and rapid propensity for developing antimicrobial resistance. Since very few treatment options exist, clinicians face an important challenge in the management of the infection. In this scenario, little is known regarding the transmission dynamics of M. genitalium and the epidemiology of antimicrobial resistance. This mgpB-based molecular typing study, conducted among 54 asymptomatically infected individuals prospectively recruited from an STI screening service, reveals two distinct epidemiological clusters that significantly correlate with sexual conduct in heterosexuals and men who have sex with men (MSM), respectively. This well-defined structuration suggests the presence of two independent sexual networks with little connectivity between them. On the other hand, the study demonstrates the multiclonal feature of the emergence of antibiotic resistance in M. genitalium to both macrolides and fluoroquinolones. The high prevalence of macrolide resistance in M. genitalium among MSM, influenced by dense network connectivity and strong antibiotic selective pressure, may correspond to allodemics affecting other STIs such as gonorrhea, syphilis and enteric pathogens. Collaterally, the structural and functional impact of mutations in the mgpB gene, encoding the major adhesin P140 (MgpB), may require further investigation.

High Prevalence of Vaginal and Rectal Mycoplasma genitalium Macrolide Resistance Among Female Sexually Transmitted Disease Clinic Patients in Seattle, Washington.

BACKGROUND: Rectal Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (GC) are increasingly recognized as common infections among women. Little is known about the prevalence of rectal Mycoplasma genitalium (MG), rectal MG/CT/GC coinfection, or MG antimicrobial resistance patterns among women. METHODS: In 2017 to 2018, we recruited women at high risk for CT from Seattle's municipal sexually transmitted disease clinic. Participants self-collected vaginal and rectal specimens for CT/GC nucleic acid amplification testing. We retrospectively tested samples for vaginal and rectal MG using nucleic acid amplification testing and tested MG-positive specimens for macrolide resistance-mediating mutations (MRM) and ParC quinolone resistance-associated mutations (QRAMs). RESULTS: Of 50 enrolled women, 13 (26%) tested positive for MG, including 10 (20%) with vaginal MG and 11 (22%) with rectal MG; 8 (62%) had concurrent vaginal/rectal MG. Five (38%) were coinfected with CT, none with GC. Only 2 of 11 women with rectal MG reported anal sex in the prior year. Of MG-positive specimens, 100% of rectal and 89% of vaginal specimens had an MRM. There were no vaginal or rectal MG-positive specimens with ParC QRAMs previously associated with quinolone failure. Five MG-infected women received azithromycin for vaginal CT, 4 of whom had a MG MRM detected in their vaginal and/or rectal specimens. CONCLUSIONS: We observed a high prevalence of macrolide-resistant vaginal and rectal MG among a population of women at high risk for CT. This study highlights how the use of antimicrobials designed to treat an identified infection-in this case, CT-could influence treatment outcomes and antimicrobial susceptibility in other unidentified infections.

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

BACKGROUND: Although Mycoplasma genitalium (MG) is an acknowledged cause of nongonococcal urethritis (NGU), access to diagnostic testing is limited. Syndromic management is common, yet little is known about natural history. METHODS: Between August 2014 and April 2016, 13 heterosexual men aged ≥16 years with MG were identified within a cohort study of men with and without NGU attending an urban sexually transmitted diseases clinic. Men had 6-7 monthly visits. NGU was defined as ≥5 polymorphonuclear leukocytes per high-power field on urethral Gram stain plus either visible urethral discharge or urethral symptoms. Men with NGU received 1 g of azithromycin. Men with persistent NGU received moxifloxacin 400 mg for 14 days. First-void urine was retrospectively tested for MG using transcription-mediated amplification. Resistance-associated mutations were detected by polymerase chain reaction (PCR) and sequencing. Organism load was determined by quantitative PCR. RESULTS: Sixty-two percent of MG-positive men had macrolide resistance-mediating mutations (MRMM) at enrollment; 31% had parC mutations (all outside the quinolone resistance-determining region). MG persisted after azithromycin in 7 men, 6 of whom had MRMM. The median duration of persistence in the absence of curative therapy was 143 days (range, 21-228). Five men experienced symptom resolution after azithromycin, but MG persisted for another 89-186 days before moxifloxacin. Organism load was somewhat lower in MRMM than wild-type infections (P = .16). CONCLUSIONS: The high prevalence of macrolide resistance and long duration of infection after symptom resolution highlights the need for diagnostic MG testing of men with NGU to direct therapy.

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

Background: Rising macrolide and quinolone resistance in Mycoplasma genitalium necessitate new treatment approaches. We evaluated outcomes of sequential antimicrobial therapy for M. genitalium guided by a macrolide-resistance assay. Methods: In mid-2016, Melbourne Sexual Health Centre switched from azithromycin to doxycycline (100 mg twice daily for 7 days) for nongonococcal urethritis, cervicitis, and proctitis. Cases were tested for M. genitalium and macrolide-resistance mutations (MRMs) by polymerase chain reaction. Directly after doxycycline, MRM-negative infections received 2.5 g azithromycin (1 g, then 500 mg daily for 3 days), and MRM-positive infections received sitafloxacin (100 mg twice daily for 7 days). Assessment of test of cure and reinfection risk occurred 14-90 days after the second antibiotic. Results: Of 244 evaluable M. genitalium infections (52 women, 68 heterosexual men, 124 men who have sex with men) diagnosed from 20 June 2016 to 15 May 2017, MRMs were detected in 167 (68.4% [95% confidence interval {CI}, 62.2%-74.2%]). Treatment with doxycycline decreased bacterial load by a mean 2.60 log10 (n = 56; P < .0001). Microbiologic cure occurred in 73 of 77 MRM-negative infections (94.8% [95% CI, 87.2%-98.6%]) and in 154 of 167 MRM-positive infections (92.2% [95% CI, 87.1%-95.8%]). Selection of macrolide resistance occurred in only 2 of 76 (2.6% [95% CI, .3%-9.2%]) macrolide-susceptible infections. Conclusions: In the context of high levels of antimicrobial resistance, switching from azithromycin to doxycycline for presumptive treatment of M. genitalium, followed by resistance-guided therapy, cured ≥92% of infections, with infrequent selection of macrolide resistance.

Multicenter Clinical Evaluation of a Novel Multiplex Real-Time PCR (qPCR) Assay for Detection of Fluoroquinolone Resistance in Mycoplasma genitalium.

Mycoplasma genitalium causes a common sexually transmitted infection with a marked propensity to develop antimicrobial resistance. As few treatment options exist, this poses significant challenges to clinicians. Recent diagnostic advances have resulted in tests that report the simultaneous detection of M. genitalium and any resistance to macrolides, the first-line treatment. This allows for therapy to be tailored to the individual, thereby optimizing treatment outcomes. However, resistance to fluoroquinolones, the second-line treatment, is increasing in M. genitalium In this study, we describe a new assay, MG+parC (beta), which simultaneously reports the detection of M. genitalium and five parC mutations that have been associated with resistance to fluoroquinolones. These mutations affect the amino acid sequence of ParC at residues S83R (A247C), S83I (G248T), D87N (G259A), D87Y (G259T), and D87H (G259C). The study tested the MG+parC (beta) assay with 202 M. genitalium-positive clinical samples from Australia (n = 141) and Spain (n = 61). Compared to Sanger sequencing, the assay performed with a kappa value of 0.985 (95% confidence interval [CI], 0.955 to 1.000), with a mutation detection sensitivity of 97.6% (95% CI, 87.4 to 99.9), and specificity of 100.0% (95% CI, 97.7 to 100.0). Fluoroquinolone resistance-associated mutations in parC targeted by the assay were more prevalent among the Australian cohort (23.4% [95% CI,16.3 to 31.8]) compared to the Spanish population (8.8% [95% CI, 2.9% to 19.3%]) (P = 0.019). The MG+parC (beta) kit is a simple and reliable method for simultaneous detection of M. genitalium and fluoroquinolone resistance-associated mutations in clinical settings. This novel diagnostic tool may extend the utility of the second line of antimicrobial therapies in M. genitalium infection.

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.

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

BACKGROUND: Standard counseling at nongonococcal urethritis (NGU) diagnosis includes advice to abstain from sex for at least 7 days and until symptoms resolve. METHODS: From December 2014 to July 2018, we enrolled men who have sex with men and received azithromycin (1 g) for NGU at the Public Health-Seattle and King County STD Clinic. Over 12 weeks of follow-up, participants reported daily urethral symptoms and sexual activity on web-based diaries. Nongonococcal urethritis was defined as urethral symptoms or visible urethral discharge plus 5 or greater polymorphonuclear leukocytes per high-power field. Time of symptom resolution was defined as the first of 5 consecutive asymptomatic days. RESULTS: Of 100 participants with NGU and no Chlamydia trachomatis (CT)/Mycoplasma genitalium (MG) coinfection, 36 (36%), 22 (22%), and 42 (42%) had CT-NGU, MG-NGU, and non-CT/non-MG NGU, respectively. Among men with MG-NGU, 94% had a macrolide resistance mutation. For all etiologies, median time to symptom resolution after azithromycin was 7 days (95% confidence interval [CI], 5-9); 37% had symptoms lasting longer than 7 days. For men with CT-NGU, MG-NGU, and non-CT/non-MG NGU, median time to symptom resolution was 4 days (95% CI, 2-6; 16% >7 days), undefined days (95% CI, 7 to undefined; 60% >7 days), and 7 days (95% CI, 5-11; 46% >7 days), respectively. Median time to first sexual activity (any type) was 12 days (95% CI, 11-17); it was 16 days (95% CI, 12-18) to first urethral sexual exposure. Twenty-seven percent did not avoid urethral exposure for the recommended period. CONCLUSIONS: Counseling at NGU diagnosis should educate patients that symptoms may persist more than 7 days, particularly for non-CT NGU, and emphasize the rationale for the 7-day abstinence period.

Four-color multiplex real-time PCR assay prototype targeting azithromycin resistance mutations in Mycoplasma genitalium.

BACKGROUND: The worldwide expansion of macrolide-resistant Mycoplasma genitalium (MG) in cases of genital infections has led to an increased recurrence rate of these infections after first-line azithromycin treatment. By detecting the presence of azithromycin-resistant MG, the patient's antibiotic treatment can be targeted and the spread of resistance prevented. With this aim in mind, macrolide-resistance detection kits are helpful tools for the physician. METHODS: Azithromycin resistance mutations in MG are targeted using a four-color multiplex real-time RT-PCR assay. Tested targets include plasmid DNA (as positive controls) as well as macrolide-sensitive and macrolide-resistant genomic DNA from characterized cell lines and clinical samples. RESULTS: The analytical data presented here were generated from plasmid DNA and genomic RNA/DNA and include adaptation to an internal control, specificity between targets, specificity vs non-MG species, limit of detection (LoD) and interference studies (co-infection and endogenous substances). The clinical data were based on the application of the assay to clinical samples characterized by sequencing. CONCLUSIONS: A new NAAT (nucleic acid amplification test) prototype has been developed in collaboration with the Diagenode s.a. company, this prototype targets MG and azithromycin-resistance mutations in that pathogen.

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.

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.

Mycoplasma genitalium: whole genome sequence analysis, recombination and population structure.

BACKGROUND: Although Mycoplasma genitalium is a common sexually transmitted pathogen causing clinically distinct diseases both in male and females, few genomes have been sequenced up to now, due mainly to its fastidious nature and slow growth. Hence, we lack a robust phylogenetic framework to provide insights into the population structure of the species. Currently our understanding of the nature and diversity of M. genitalium relies on molecular tests targeting specific genes or regions of the genome and knowledge is limited by a general under-testing internationally. This is set against a background of drug resistance whereby M. genitalium has developed resistance to mainly all therapeutic antimicrobials. RESULTS: We sequenced 28 genomes of Mycoplasma genitalium from temporally (1980-2010) and geographically (Europe, Japan, Australia) diverse sources. All the strain showed essentially the same genomic content without any accessory regions found. However, we identified extensive recombination across their genomes with a total of 25 regions showing heightened levels of SNP density. These regions include the MgPar loci, associated with host interactions, as well as other genes that could also be involved in this role. Using these data, we generated a robust phylogeny which shows that there are two main clades with differing degrees of genomic variability. SNPs found in region V of 23S rRNA and parC were consistent with azithromycin/erythromycin and fluoroquinolone resistances, respectively, and with their phenotypic MIC data. CONCLUSIONS: The sequence data here generated is essential for designing rational approaches to type and track Mycoplasma genitalium as antibiotic resistance increases. It represents a first approach to its population genetics to better appreciate the role of this organism as a sexually transmitted pathogen.