Estimation of the real magnitude of antimicrobial resistance ofMycoplasma genitaliumin Belgium by implementing a prospective surveillance programme

Objectives Antimicrobial resistance of Mycoplasma genitalium (MG) is a growing concern worldwide. Because reliable data on the burden of resistant MG in Belgium are missing, an additional prospective surveillance program was implemented in 2022 to estimate the real burden of resistant MG in Belgium. Methods Belgian laboratories (n=21) provided frozen remnants of MG positive samples to the National Reference Centre of Sexually Transmitted Infections from July to November 2022. The presence of macrolide and fluoroquinolones resistance associated mutations (RAMs) was assessed using Sanger sequencing of the 23SrRNA and parC gene. Differences in resistance patterns were correlated with surveillance methodology, socio-demographic and behavioral variables via Fisher’s exact test and logistic regression analysis. Results Sequencing for both macrolide and fluoroquinolone RAMs was successful for 232/244 MG positive samples. Over half of the samples were resistant to macrolides (55.2%). All MG in samples from men who have sex with men (MSM) (24/24) were resistant to macrolides. The presence of fluoroquinolone RAMs was estimated to be 26% and did not differ with socio-demographic and sexual behaviour characteristics. Conclusions Given the considerable cost of macrolide resistance testing, our data suggest that the use of macrolide resistance testing in MSM does not seem justified in Belgium. However, the lower prevalence of macrolide resistance in other population groups, combined with further emergence of fluoroquinolone resistance provides evidence for macrolide resistance testing in these groups. Continued surveillance of resistance in MG in all groups will be crucial to guide national testing- and treatment strategies.