Mycoplasma genitalium acquisition and macrolide resistance after initiation of HIV pre-exposure prophylaxis in men who have sex with men

Objectives Recent evidence shows that patients using HIV pre-exposure prophylaxis (PrEP) have an increased rate of bacterial STIs, including syphilis, chlamydia and gonorrhoea. Our study aimed to describe the acquisition and the susceptibility for macrolides ofMycoplasma genitaliumin men who have sex with men (MSM) on PrEP. Methods We studied all MSM who started PrEP in the AZ Sint-Jan Hospital Bruges from 1 June 2017 to 31 March 2019 with at least one follow-up visit. Patients were screened forM. genitaliumand other STIs with pooled rectal swabs, pharyngeal swabs and first-voided urine, and blood samples at baseline and quarterly intervals after initiating PrEP. TaqMan Array Card technology was used to detectM. genitaliumand determine macrolide-resistance mediating mutations in region V of the 23S rRNA gene (A2058G, A2059G, A2058C and others). Patients with an STI were treated based on a national guideline. Results 131 MSM (median age 40 years, range 20-79) were included in the study. The median follow-up time was 12 months (IQR 6.1-17). Baseline prevalence ofM. genitaliumwas 6.9% and incidence rate after PrEP initiation was 28.8 per 100 person-years (95% CI 21.7 to 37.2), without significant differences in proportions between the first four quarterly intervals. All but one acquisitions were asymptomatic. Younger age and positivity forM. genitaliumat baseline were significantly associated with incidentM. genitaliumacquisition. The observed proportion of macrolide resistance increased not significantly from 44% at baseline to 57%-86% after PrEP initiation. None of the 27 macrolide-resistantM. genitaliumacquisitions could be linked to azithromycin exposure in the three preceding months. Conclusions After initiation of PrEP, we found a stable incidence of almost exclusively asymptomaticM. genitalium. However, a non-significant trend of an increased percentage of macrolide-resistant strains was observed