Background Mycoplasma genitalium (MG) is an emerging cause of urethritis. Although an FDA-approved MG diagnostic test is now available in the U.S., syndromic management of urethritis remains widespread. Little is known about the geographic distribution of MG resistance in the U.S. and associated clinical outcomes. We evaluated the frequency of MG among men with urethritis, antimicrobial susceptibility of MG, and post-treatment symptom persistence.

Methods We enrolled men presenting with urethritis symptoms to 6 U.S. STD clinics during June 2017–July 2018. Participants with urethritis confirmed on stained urethral smear were eligible for a follow-up phone call 14–17 days post-enrollment and chart review. Urethral specimens were tested locally for N. gonorrhoeae and C. trachomatis. CDC tested specimens for MG and T. vaginalis. MG resistance mutations were detected by targeted amplification/Sanger sequencing of 23S rRNA loci (macrolide resistance mutations [MRM]) and parC and gyrA (quinolone resistance mutations).

Results Among 914 participants with evaluable MG results, MG was detected in 28.7% (95% CI 23.8–33.6). Men with MG were more often black (79.8% vs 66%), <30 years (72.9% vs 56.2%), and reported only female partners (83.7% vs 74.2%) than men without MG. Among MG+ participants, MRM was detected in 62.2% (range 53%–72.3%), parC mutations in 11.5% (range 6.6–18.4%), and gyrA in 0%. Among 763 participants with follow-up, 19.8% reported symptom persistence, without clinically meaningful difference by MG status. Among MG participants treated with azithromycin, those with MRM more often reported persistent symptoms (35.1%) and were more likely to return to clinic within 45 days than those without MRM.

Conclusion MG was common among men with urethritis and MRM prevalence high. Persistent symptoms were frequent among men with and without MG. Many participants with macrolide-resistant MG experienced symptom persistence and returned to clinic for evaluation.

Disclosure No significant relationships.