Surveillance of the prevalence of macrolide and/or fluoroquinolone resistance-associated mutations in Mycoplasma genitalium in Japan.

To clarify the status of macrolide and fluoroquinolone resistance of clinical strains of Mycoplasma genitalium in Japan, we amplified portions of the gyrA, parC, and 23S rRNA genes from DNAs in 627 first-voided urine specimens collected from men with M. genitalium-positive urethritis who visited clinics mainly in Sendai, Tokyo, and Osaka, Japan, from 2013 to 2017, by PCR and sequenced. The incidence of single amino acid changes at Met95 or Asp99 in GyrA increased chronologically and was approximately 10% from 2015 onward. The incidence of amino acid changes at Ser83 or Asp87 in ParC was approximately 50% in 2013 but increased to 60–70% from 2014 to 2017. The incidence of mutations at A2071 or A2072 in the 23S rRNA gene increased chronologically and reached over 70% in 2017. The prevalence of M. genitalium harboring alterations in ParC and mutations in the 23S rRNA gene increased and was approximately 50% in 2016 and 2017. The prevalence of M. genitalium with alterations in both GyrA and ParC and mutations in the 23S rRNA gene, which could be associated with treatment failures with the sitafloxacin and azithromycin regimens, were approximately 15% and 10% in 2016 and 2017, respectively. The prevalence of M. genitalium with genetic alterations associated with resistance to fluoroquinolones and/or macrolides is increasing rapidly in Japan. We must prevent the further selection of multi-drug-resistant M. genitalium so that M. genitalium infections will not become untreatable.