Worryingly high prevalence of resistance-associated mutations to macrolides and fluoroquinolones in Mycoplasma genitalium among men who have sex with men with recurrent sexually transmitted infections

BACKGROUND: Men who have sex with men (MSM) using pre-exposure prophylaxis (PrEP) recurrently infected with STIs are playing a pivotal role in contemporary Sexually transmitted infections (STI) epidemics. Our aim was to assess whether these individuals had more Mycoplasma genitalium (M. genitalium) infections and more resistance to macrolides and fluoroquinolones of M. genitalium compared to those who were not recurrently infected with STIs.

METHODS: The study was performed on 179 Belgian MSM PrEP users that were followed up for 18 months. STIs including M. genitalium were detected quarterly. Detection of resistance-associated mutations (RAMs) to macrolides and fluoroquinolones was performed via Sanger sequencing of the 23S rRNA gene and parC gene (conferring mutations at position 83/87 in ParC). Differences in M. genitalium positivity rate and presence of RAMs between both groups were assessed using mixed-effects logistic regression.

RESULTS: A total of 91 new M. genitalium infections were detected among 70 participants. MSM experiencing recurrent STIs have significantly more M. genitalium infections compared to those without (11.7% vs. 4.7% OR: 2.69). Importantly, the prevalence of RAMs to macrolides (95.2% vs. 77.4%) and fluoroquinolones (35.7% vs. 12.9%) was much higher among individuals with recurrent STIs. The difference was only statistically significant for macrolides (OR 5.83, p = .036).

CONCLUSIONS: MSM recurrently infected with STIs play a central role in the emergence of antimicrobial resistance in M. genitalium. The use of macrolides and fluoroquinolones should preferably be minimized in this population in order to avoid further emergence of multi-resistant M. genitalium.