简介:Objective:ToanalyzetypeⅡtopoisomerasegenesinclinicalisolatesoffluoroquinolone-resistantMycoplasmahominis.Methods:EightisolatesofM.hominiscrossresistantto6fluoroquinoloneswereselectedfrom103clinicalstrainsofM.hominisusingabrothmicrodilutionmethod.TypeIItopoisomerasegeneswereamplifiedbyPCRanddirectlysequenced.Nucleotidesequenceswerecomparedtosequencesfromasusceptiblestrain(M.hominisPG2I).Results:MICsofresistantMhisolateswere4-to512-foldhigherthanMICsfromthesusceptiblereferencestrain.SequencecomparisonrevealedaCtoTchangeat113ntingyrAQRDRledtothesubstitutionofSer83byLeucineandnoaminoacidchangeingyrB.AchangeofGtoTat134ntinparCQRDRledtothesubstitutionofSer80byIsoleucineandaGtoAchangeat70ntinparEQRDRledtothesubstitutionofAsparticacidbyAsparagine.Conclusion:TheseresultssuggestthataCtoTchangeatll3ntingyrA,aGtoTchangeat134ntinparCandaGtoAchangeat70ntinpatrEareassociatedwithfluoroquinoloneresistanceofM.hominis.