High prevalence of vaginal and rectal Mycoplasma genitalium macrolide resistance among female STD clinic patients in Seattle, Washington.

<bold>Background: </bold>Rectal Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (GC) are increasingly recognized as common infections among women. Little is known about the prevalence of rectal Mycoplasma genitalium (MG), rectal MG/CT/GC co-infection, or MG antimicrobial resistance patterns among women.<bold>Methods: </bold>In 2017-2018 we recruited women at high risk for CT from Seattle's municipal STD clinic. Participants self-collected vaginal and rectal specimens for CT/GC nucleic acid amplification testing (NAAT). We retrospectively tested samples for vaginal and rectal MG using NAAT, and tested MG-positive specimens for macrolide resistance-mediating mutations (MRM) and ParC quinolone resistance-associated mutations (QRAMs).<bold>Results: </bold>Of 50 enrolled women, 13 (26%) tested positive for MG, including 10 (20%) with vaginal MG and 11 (22%) with rectal MG; 8 (62%) had concurrent vaginal/rectal MG. Five (38%) were co-infected with CT; none with GC. Only 2 of 11 women with rectal MG reported anal sex in the prior year. Of MG-positive specimens, 100% of rectal and 89% of vaginal specimens had a MRM. There were no vaginal or rectal MG-positive specimens with ParC QRAMs previously associated with quinolone failure. Five MG-infected women received azithromycin for vaginal CT, four of whom had a MG MRM detected in their vaginal and/or rectal specimens.<bold>Conclusions: </bold>We observed a high prevalence of macrolide-resistant vaginal and rectal MG among a population of women at high risk for CT. This study highlights how the use of antimicrobials designed to treat an identified infection - in this case CT - could influence treatment outcomes and antimicrobial susceptibility in other unidentified infections. [ABSTRACT FROM AUTHOR]