Mycoplasma genitalium: A new superbug

Azithromycin and moxifloxacin resistance determinants in Mycoplasma genitalium in Lleida, Spain

OBJECTIVE

Mycoplasma genitalium (MG) is a microorganism related to sexually transmitted infections. Antibiotic resistance of MG leads to an increase in treatment failure rates and the persistence of the infection. The aim of this study was to describe the most frequent mutations associated with azithromycin and moxifloxacin resistance in our geographical area.

METHODS

A prospective study from May 2019 to May 2023 was performed. MG-positive samples were collected. Real-time PCRs (AllplexTM MG-AziR Assay and AllplexTM MG-MoxiR Assay, Seegene) were performed in MG positive samples to detect mutations in 23S rRNA V domain and parC gene.

RESULTS

A 37.1% of samples presented resistance determinants to azithromycin and the most common mutation detected was A2059G (57.9%). Resistance to moxifloxacin was studied in 72 azithromycin-resistant samples and 36.1% showed mutations, being G248T the most prevalent (73.1%).

CONCLUSIONS

The resistance to different lines of treat ment suggests the need for a targeted therapy and the performing of a test of cure afterwards.

Infective anoproctitis in men having sex with men: Don't forget Mycoplasma genitalium

OBJECTIVES

The aim was to describe the clinical characteristics of symptomatic anoproctitis and the occurrence of Chlamydia trachomatis (CT), Neisseria gonorrhoeae (NG) and Mycoplasma genitalium (MG) infections in a prospective cohort of MSM patients.

METHODS

From February 2018 to January 2020, all consecutive patients presenting at the Leopold Bellan Proctology Institute of Saint-Joseph Hospital, Paris, France with symptoms of anoproctitis were tested on rectal samples for C. trachomatis (CT), N. gonorrhoeae (NG), M. genitalium (MG). Clinical, microbiological, biological data, STI risk factors, medical history and treatments were collected.

RESULTS

Three hundred and sixty-five patients were included for suspected infective anoproctitis. CT was detected in 84/365 (23%) patients, NG in 45/365 (12%) and MG in 46/315 patients (15%), associated with macrolide resistance in 28/46 MG strains (61%). The most frequent symptoms were rectal pains, rectal bleeding, purulent discharge in 253 (79%), 191 (60%), and 164 (51%) of cases respectively. In comparison with MG infections, ulcerations, erythematous proctitis, rectorragia and false needs were more frequently described in CT infections, while purulent proctitis, functional pain and purulent discharge were more often observed in NG and CT anoproctitis.

CONCLUSION

We found a high prevalence rate of STIs due to CT, NG, while MG detection was associated with a high rate of macrolide resistance in a cohort of MSM patients. Our results confirm that in cases of symptomatic anoproctitis, MG should be tested in association with other STI pathogens.

Pushing the envelope: Immune mechanism and application landscape of macrophage-activating lipopeptide-2

Mycoplasma fermentans can cause respiratory diseases, arthritis, genitourinary tract infections, and chronic fatigue syndrome and have been linked to the development of the human immunodeficiency virus. Because mycoplasma lacks a cell wall, its outer membrane lipoproteins are one of the main factors that induce inflammation in the organism and contribute to disease development. Macrophage-activating lipopeptide-2 (MALP-2) modulates the inflammatory response of monocytes/macrophages in a bidirectional fashion, indirectly enhances the cytotoxicity of NK cells, promotes oxidative bursts in neutrophils, upregulates surface markers on lymphocytes, enhances antigen presentation on dendritic cells and induces immune inflammatory responses in sebocytes and mesenchymal cells. MALP-2 is a promising vaccine adjuvant for this application. It also promotes vascular healing and regeneration, accelerates wound and bone healing, suppresses tumors and metastasis, and reduces lung infections and inflammation. MALP-2 has a simple structure, is easy to synthesize, and has promising prospects for clinical application. Therefore, this paper reviews the mechanisms of MALP-2 activation in immune cells, focusing on the application of MALP-2 in animals/humans to provide a basis for the study of pathogenesis in Mycoplasma fermentans and the translation of MALP-2 into clinical applications.

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.

Eating the Enemy: Mycoplasma Strategies to Evade Neutrophil Extracellular Traps (NETs) Promoting Bacterial Nucleotides Uptake and Inflammatory Damage

Neutrophils are effector cells involved in the innate immune response against infection; they kill infectious agents in the intracellular compartment (phagocytosis) or in the extracellular milieu (degranulation). Moreover, neutrophils release neutrophil extracellular traps (NETs), complex structures composed of a scaffold of decondensed DNA associated with histones and antimicrobial compounds; NETs entrap infectious agents, preventing their spread and promoting their clearance. NET formation is triggered by microbial compounds, but many microorganisms have evolved several strategies for NET evasion. In addition, the dysregulated production of NETs is associated with chronic inflammatory diseases. Mycoplasmas are reduced genome bacteria, able to induce chronic infections with recurrent inflammatory symptoms. Mycoplasmas' parasitic lifestyle relies on metabolite uptake from the host. Mycoplasmas induce NET release, but their surface or secreted nucleases digest the NETs' DNA scaffold, allowing them to escape from entrapment and providing essential nucleotide precursors, thus promoting the infection. The presence of Mycoplasma species has been associated with chronic inflammatory disorders, such as systemic lupus erythematosus, rheumatoid arthritis, inflammatory bowel disease, Crohn's disease, and cancer. The persistence of mycoplasma infection and prolonged NET release may contribute to the onset of chronic inflammatory diseases and needs further investigation and insights.

Molecular Epidemiology of Genital Infections in Campania Region: A Retrospective Study

This study provides updated information on the prevalence and co-infections caused by genital microorganisms and pathogens: Mycoplasma genitalium, Mycoplasma hominis, Ureaplasma parvum, Ureaplasma urealyticum, Trichomonas vaginalis, and Gardnerella vaginalis, by retrospectively analyzing a cohort of patients living in the Naples metropolitan area, Campania region, Southern Italy. To investigate the genital infections prevalence in clinical specimens (vaginal/endocervical swabs and urines) collected from infertile asymptomatic women and men from November 2018 to December 2020, we used a multiplex real-time PCR assay. Of the 717 specimens collected, 302 (42.1%) resulted positive for at least one of the targets named above. Statistically significant differences in genital prevalence of selected microorganisms were detected in both women (62.91%) and men (37.08%). G. vaginalis and U. parvum represented the most common findings with an 80.2% and 16.9% prevalence in vaginal/endocervical swabs and first-voided urines, respectively. Prevalence of multiple infections was 18.18% and 8.19% in women and men, respectively. The most frequent association detected was the co-infection of G. vaginalis and U. parvum with 60% prevalence. Our epidemiological analysis suggests different infection patterns between genders, highlighting the need to implement a preventative screening strategy of genital infections to reduce the complications on reproductive organs.