临床分离志贺菌质粒介导喹诺酮类耐药基因的检测.pdfVIP

临床分离志贺菌质粒介导喹诺酮类耐药 基因的检测 刘艳艳 潘亚超 胡立芬 程君 朱玉林 叶英 李家斌 目的 了解临床分离志贺菌质粒介导喹诺酮类耐药基因的种类、分布以及对抗菌药 物的耐药性。方法 PCR法检测137株志贺菌的qnr、aac(6)-Ib-cr和qepA基因，对阳性扩增产物 进行测序分析并对阳性菌株做接合试验，采用琼脂倍比稀释法测定志贺菌、受体菌和接合子对喹诺 酮类及其他抗菌药物的最低抑菌浓度 (MIC)。PCR扩增并测序确定接合子的基因型。结果137株 志贺菌中，4株菌qnr基因阳性，占2.9％,其中3株携带qnrS2基因，1株携带qnrB4基因 （全序列在 GenBank的注册号为JF261185、HQ917003）；另外检出5株菌携带aac(6)-lb-cr基因 （全序列注册 号为JF261186），占3.6％；1株菌携带qepA基因,占0.7％。10株PCR扩增阳性的菌株中有6株转 移接合成功。接合子与受体菌相比，对喹诺酮类等抗菌药物的MIC值均有不同程度的提高。结 论 临床分离志贺菌质粒介导喹诺酮类耐药基因检出率虽较低，但这些耐药基因具有水平转移的特 性，应引起高度重视。 志贺菌属；质粒；喹诺酮类；基因，细菌；抗药性，细菌；蛋白质亚型 Detectionofgenotypesofplasmid-mediatedquinoloneresistanceinclinicalisolatesofShigella LIU Yan-yan PANYa-chao HULi-fen CHENG Jun ZHU Yu-lin YEYing LIJia-bin DepartmentofInfectiousDiseases,FirstAffiliatedHospital,AnhuiMedicalUniversity,Hefei 230022,China Objective Toinvestigatethevariationsanddistributionsoftheplasmid-mediated quinoloneresistancegenesinclinicalisolatesofShigellaandtheirresistancetoantimicrobialagents. Methods qnr,aac(6)-Ib-crandqepAgeneswereidentifiedbypolymerasechainreaction(PCR)in 137clinicalisolatesofShigella. DNAsequencingofgene-positivestrainswereanalyzedandthe conjugationexperimentwasperformed.Theminimalinhibitoryconcentrations(MIC)ofShigella isolates,recipientstrainsandtransconjugantsweretestedbyagardilutionmethodforquinolonesand otherantimicrobialagents.ThegenotypeoftransconjugantsweredeterminedbyPCRandsequencing. Results Four(2.9％)strainsofthe137Shigellaisolateswereqnrgenepositive,including3qnrS2 positiveand1qnrB4positive(GenBankaccessionnumbersofthecompletesequencewereJF261185 andHQ917003,respectively). Furthermore, five(3.6％)aac(6)-Ib-crgene-positivestrains (GenBankaccessionnumberJF261186)andone(0.7％)qepAgene-positivestrainwereidentifiedin allisolates.TheconjugationexperimentsweresuccessfullycarriedoutinsixoutoftenPCR-positive isolates.TheMICoftransconjugantsagainstquinolonesandotherantimicrobialagentsincreased differentlycomparedtorecipientstrains.Conclu