Impact of 16S rRNA Single Nucleotide Polymorphisms on Mycoplasma genitalium Organism Load with Doxycycline Treatment

German evidence- and consensus-based guideline on the management of penile urethritis

Urethritis is a common condition predominantly caused by sexually transmitted pathogens such as Chlamydia trachomatis, Neisseria gonorrhoeae, and Mycoplasma genitalium. It is not possible to differentiate with certainty between pathogens on the basis of clinical characteristics alone. However, empirical antibiotic therapy is often initiated in clinical practice. The aim of this clinical practice guideline is to promote an evidence-based syndrome-orientated approach to the management of male adolescents and adults with symptoms of urethritis. Besides recommendations for the diagnosis, classification and choice of treatment, this guideline provides recommendations for the indication to empirically treat patients with penile urethritis. A novel feature compared to existing, pathogen-specific guidelines is the inclusion of a flowchart for the syndrome-orientated practical management. For suspected gonococcal urethritis requiring empirical treatment, ceftriaxone is recommended. Due to the risk of Chlamydia trachomatis co-infection, doxycycline should also be prescribed, unless follow-up for the treatment of possible co-infections is assured. For suspected non-gonococcal urethritis, doxycycline is the recommended empirical treatment. In the empiric treatment of both gonococcal and non-gonococcal penile urethritis, azithromycin is reserved for cases where doxycycline is contraindicated. This guideline also includes detailed recommendations on differential diagnosis, pathogen-specific treatments and specific situations, as well as patient counselling and follow-up.

Chinese advances in understanding and managing genitourinary tract infections caused by Mycoplasma genitalium, Mycoplasma hominis, and Ureaplasma urealyticum

Mycoplasma genitalium, Ureaplasma urealyticum and Mycoplasma hominis are bacterial pathogens found in the genitourinary tract, implicated in a range of infections. In women, these infections including pelvic inflammatory disease, vaginitis, infertility, and cervical cancer, while in men, they can cause non-gonococcal urethritis, prostate cancer, among other conditions. These infections are a global health concern, with China identified as a country with a high prevalence. This review provides a comprehensive overview of the epidemiology, causative factors, and diagnostic methods for these three Mycoplasma species with in China. The rise of multi-drug resistance, driven by antibiotics overuse, poses a significant challenge to treatment, complicating patient management. These Mycoplasma species employ unique adhesion mechanisms that trigger a cascade of signal transduction, culminating to inflammatory responses, tissue damage, and the release of toxic metabolites. Here, we delineate the mechanisms of underlying Mycoplasma resistance and propose key therapeutic strategies for these three mycoplasmas in China. This includes a summary of effective antibiotic treatment strategies, and potential combinations of therapeutic to improve cure rates, and a discussion of potential therapeutic approaches using traditional Chinese medicine.

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.

Antimicrobial treatment and resistance in sexually transmitted bacterial infections

Sexually transmitted infections (STIs) have been part of human life since ancient times, and their symptoms affect quality of life, and sequelae are common. Socioeconomic and behavioural trends affect the prevalence of STIs, but the discovery of antimicrobials gave hope for treatment, control of the spread of infection and lower rates of sequelae. This has to some extent been achieved, but increasing antimicrobial resistance and increasing transmission in high-risk sexual networks threaten this progress. For Neisseria gonorrhoeae, the only remaining first-line treatment (with ceftriaxone) is at risk of becoming ineffective, and for Mycoplasma genitalium, for which fewer alternative antimicrobial classes are available, incurable infections have already been reported. For Chlamydia trachomatis, in vitro resistance to first-line tetracyclines and macrolides has never been confirmed despite decades of treatment of this highly prevalent STI. Similarly, Treponema pallidum, the cause of syphilis, has remained susceptible to first-line penicillin.

Efficacy of Minocycline for the Treatment of Mycoplasma genitalium

Background

High levels of macrolide resistance and increasing fluoroquinolone resistance are making Mycoplasma genitalium increasingly difficult to treat. Minocycline is an alternative treatment for patients with macrolide-resistant M genitalium infections that have failed moxifloxacin, or for those with fluoroquinolone contraindications or resistance. Published efficacy data for minocycline for M genitalium are limited.

Methods

We evaluated minocycline 100 mg twice daily for 14 days at Melbourne Sexual Health Centre (MSHC). Microbial cure was defined as a negative test of cure within 14-90 days after completing minocycline. The proportion cured and 95% confidence intervals (CIs) were calculated, and logistic regression was used to explore factors associated with treatment failure. We pooled data from the current study with a prior adjacent case series of patients with M genitalium who had received minocycline 100 mg twice daily for 14 days at MSHC.

Results

Minocycline cured 60 of 90 (67% [95% CI, 56%-76%]) infections. Adherence was high (96%) and side effects were mild and self-limiting. No demographic or clinical characteristics were associated with minocycline failure in regression analyses. In the pooled analyses of 123 patients, 83 (68% [95% CI, 58%-76%]) were cured following minocycline.

Conclusions

Minocycline cured 68% of macrolide-resistant M genitalium infections. These data provide tighter precision around the efficacy of minocycline for macrolide-resistant M genitalium and show that it is a well-tolerated regimen. With high levels of macrolide resistance, increasing fluoroquinolone resistance, and the high cost of moxifloxacin, access to nonquinolone options such as minocycline is increasingly important for the clinical management of M genitalium.

Update in Epidemiology and Management of Mycoplasma genitalium Infections

Mycoplasma genitalium is a frequent cause of urogenital syndromes in men and women and is associated with adverse sequelae in women. M genitalium also infects the rectum, and may cause proctitis, but rarely infects the pharynx. Diagnosis requires nucleic acid amplification testing. Antibiotic resistance is widespread: more than half of infections are resistant to macrolides and fluoroquinolone resistance is increasing. Resistance-guided therapy is recommended for symptomatic patients, involving initial treatment with doxycycline to reduce organism load followed by azithromycin for macrolide-sensitive infections or moxifloxacin for macrolide-resistant infections. Neither screening nor tests of cure are recommended in asymptomatic persons.