Original Article
Resistance mechanism of Mycoplasma hominis to quinolones in Chengdu area
Hongyan Zhang, Yun Xia, Juan Zhao, Shaochuan Ding, Xiaoyan Miao
Published 2018-05-11
Cite as Chin J Lab Med, 2018, 41(5): 385-389. DOI: 10.3760/cma.j.issn.1009-9158.2018.05.012
Abstract
ObjectiveTo detect the resistance of Mycoplasma hominis to quinolones in Chengdu area, explore resistance mechanism of topoisomerase gene gyrA, gyrB, parC and parE mutations associated with drug resistance and provide epidemiological data.
MethodsMycoplasma hominis was identified by 16SrRNA gene sequencing technique and antibiotic susceptibility test was carried out by broth microdilution method. Resistance genes were amplified by PCR, whereas sequence alignment was analyzed by DNAMAN software and BLAST.
ResultsResistance rates of Mycoplasma hominis to ciprofloxacin, levofloxacin, moxifloxacin and gatifloxacin were 92.4%(61/66), 87.9%(58/66), 71.2%(47/66) and 66.7%(44/66), respectively.Totally 45 strains with different susceptibility to quinolones were screened for amplification and sequencing of topoisomerase genes, of which, 31 strains resistant to moxifloxacin and gatifloxacin harbored GyrA S153L amino acid mutation, 68.9%(31/45), 41 strains resistant to ciprofloxacin and levofloxacin harbored ParC S91I amino acid mutation, 91.1%(41/45). In addition, a new amino acid substitution of ParE A463S was found in 2 high-level resistant strains. No amino acid change was found in GyrB.
ConclusionsResistance of Mycoplasma hominis to quinolones is closely associated with amino acid changes caused by mutations in gyrA and parC genes. Different quinolones have different targeting roles and high level resistance is associated with multiple gene mutations.(Chin J Lab Med, 2018, 41: 385-389)
Key words:
Mycoplasma hominis; Quinolones; Drug resistance, bacterial; DNA Gyrase; DNA Topoisomerase Ⅳ; Mutation
Contributor Information
Hongyan Zhang
Department of Laboratory Medicine, the First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China
Yun Xia
Juan Zhao
Shaochuan Ding
Xiaoyan Miao