Mycoplasma genitalium macrolide resistance update: Rate among a 2016-2017 cohort of patients in Barcelona, Spain.

INTRODUCTION:Mycoplasma genitalium is a major cause of urethritis and other genital syndromes. Antibiotic resistance, especially to macrolides, is increasing at an alarming rate worldwide. The aim of this study was to estimate the rate of macrolide resistance in M. genitalium among a 2016-2017 cohort of patients in Barcelona, Spain; and to compare this estimate with previous data from 2013 to 2014 in this region. METHODS:The study was conducted retrospectively with M. genitalium-positive samples collected between December 2016 and February 2017 at the Hospital Vall d'Hebron Microbiology Department. Genotypic markers of macrolide resistance were primarily detected using the ResistancePlus® MG molecular assay (SpeeDx). Mutations were then confirmed by sequencing. RESULTS:Macrolide resistance-mediating mutations were detected in 30/83 infections (36.1% [95% CI, 25.9%-47.4%]). This resistance was more frequent among men who have sex with men (55.0% [95% CI, 38.5%-70.7%]) compared to heterosexual men (27.3% [95% CI, 10.7%-50.2%]) and women (9.5% [95% CI, 1.3%-30.4%]), p<0.001. Additionally, macrolide resistance did not significantly increase in this cohort when compared with previous investigations. CONCLUSION:Despite the current notable rate of macrolide resistance in M. genitalium, resistance did not significantly increase between 2013-2014 and 2016-2017 in our region. Nevertheless, strict local surveillance and the implementation of rapid diagnostic tests that combine the detection of the bacterium and resistance-mediating mutations may facilitate the optimization of antibiotic administration and reduce the transmission of resistance in M. genitalium.