Study for detection and treatment of multidrug-resistant Mycoplasma genitalium

2019 Fiscal Year Final Research Report

• Project/Area Number: 17K11193
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Urology
• Research Institution: University of Occupational and Environmental Health, Japan
• Principal Investigator: HAMASUNA Ryoichi 産業医科大学, 医学部, 非常勤医師 (30189609)
• Co-Investigator(Kenkyū-buntansha): 松本 正広 産業医科大学, 医学部, 助教 (20580294)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Keywords: mycoplasma genitalium / 尿道炎 / マクロライド耐性 / キノロン耐性 / moxifloxacin 耐性 / parC / TMA

Outline of Final Research Achievements

From Japanese patients with non-gonococcal urethritis, new 13 Mycoplasma genitalium strains were isolated and cultured. We analyzed antimicrobial susceptibility and genome mutations of　total 18 strains including 13 new isolates, type strain and 4 strains isolated at 2014. Among these strains, 12 strains were macrolide-resistant and had MRAM on 23S rRNA gene. In addition, 9 strains had MIC with more than 1 mg/ml against moxifloxacin (MFLX. By sequence of QRDR of ParC, strains with more than 1 mg/L MIC of MFLX had mutation with amino-acid change such as Ser83→Ile, but strains with mutation such as Ser83→Asn did not elevate MIC of MFLX.To know the sensitivity of transcription-mediated amplification (TMA) method, the detection limit was measured among 20 stocked M. genitalium strains. The detection limit of TMA method were 0,03-0.87 DNA copies.

Free Research Field

性感染症

Academic Significance and Societal Importance of the Research Achievements

Mycoplasma genitaliumは男性尿道炎、子宮頚管炎の原因微生物である。近年、薬剤耐性が進行しており、クラミジア感染症と同じ抗菌薬で治療困難例が増加している。本研究では、M. genitaliumの分離培養法を行い、新しい株の薬剤耐性、遺伝子変異の研究を行った。13株を分離し、うち12株がマクロライド耐性、９株がキノロン耐性であった。キノロン耐性はParCのキノロン耐性決定領域のシークエンスを行い、83番のSerineがisoleucineeへのアミノ酸変異を含む遺伝子変異が牽連があることを見出した。