Should Mycoplasma penetrans be considered a pathogen in anal specimens from men who have sex with men?

This study was performed to assess the prevalence of Mycoplasma penetrans in anal samples collected from men who have sex with men (MSM) undergoing screening for Chlamydia trachomatis and Neisseria gonorrhoeae and to identify factors associated with the presence of M. penetrans.

From July to November 2022, all anal specimens from MSM submitted for C. trachomatis and N. gonorrhoeae detection as part of routine care were prospectively collected. M. penetrans was detected using a real-time PCR. Demographic, clinical, and biological data were obtained from the patients' medical records.

The prevalence of M. penetrans was 6.8% (23/338). No individuals reported anal symptoms. Having had a previous sexually transmitted infection within the past 12 months or a history of treated syphilis was associated with M. penetrans positivity (P = 0.003). The prevalence of M. penetrans was 8.2% (18/220) among MSM living with HIV and 4.2% (5/118) among HIV-negative MSM (P = 0.26).

There is a strong association between behavioral factors in MSM and the detection of M. penetrans in anal samples. However, the findings suggest colonization rather than infection, indicating that this microorganism should not be regarded as a pathogen in anal specimens.