Prevalence of Mycoplasma genitalium and antibiotic resistance-associated mutations in an Icelandic STI population, and comparison of the S-DiaMGTV and Aptima Mycoplasma genitalium assays for diagnosis.

Mycoplasma genitalium is prevalent among attendees in sexually transmitted infection (STI) clinics, and therapy is hampered by rapidly rising levels of resistance to azithromycin and moxifloxacin. In this study, we evaluated, for the first time in Iceland, the prevalence of M. genitalium and azithromycin and moxifloxacin resistance-associated mutations and assessed the diagnostic performance of the CE/in vitro diagnosis (IVD)-marked S-DiaMGTV (Diagenode Diagnostics) versus the U.S. FDA/CE/IVD-approved Aptima MG (AMG; Hologic) for M. genitalium detection. From October 2018 to January 2019, urine and vaginal swabs were provided by male and female attendees at Iceland's only STI clinic. Specimens were tested with S-DiaMGTV and AMG, and resistance-associated mutations were determined by 23S rRNA gene and parC sequencing. Demographic and clinical data were collected from patient records. M. genitalium prevalence was 9.3% overall; 7.7% (38/491) among male and 10.9% (53/487) among female participants. Azithromycin and moxifloxacin resistance-associated mutations were found in 57.0% (45/79) and 0.0% (0/80) of evaluable specimens, respectively. Sensitivity was 72.5% and 100%, and specificity was 99.9% and 100% for S-DiaMGTV and AMG, respectively. No association was found between M. genitalium and symptoms of urethritis in men. Prevalence rates for M. genitalium and azithromycin resistance-associated genes in Iceland are among the highest reported in Europe. The significantly higher sensitivity of AMG over that of S-DiaMGTV can have important clinical implications. More information is urgently needed to clarify the significance of false-negative results obtained with S-DiaMGTV and other similarly performing widely used real-time PCR methods for diagnosis and management of this sexually transmitted infection.