耐碳青霉烯肺炎克雷伯菌耐药基因检测及其同源性分析

    The detection of drug resistance genes of carbapenem-resistant Klebsiella pneumonia and its homology analysis

    • 摘要:
      目的研究六安市人民医院耐碳青霉烯肺炎克雷伯菌(CRKP)的耐药基因及同源性。
      方法收集2018年4-6月分离自临床标本的肺炎克雷伯菌40株,用法国梅里埃VITEK 2 COMPACT全自动细菌鉴定药敏仪进行鉴定和药敏。采用改良Hodge试验(MHT)和改良碳青霉烯灭活试验(mCIM)对40株菌进行碳青霉烯酶表型的筛选,采用PCR方法检测其是否携带已知的主要碳青霉烯耐药基因KPC、OXA-48、NDM-1。基质辅助激光解吸电离飞行时间质谱(MALDI-TOF MS)对其进行同源性分析。
      结果40株CRKP多分离自ICU病房(占55%),以呼吸道来源标本为主(占80%),对常用抗生素头孢菌素类、氨基糖苷类以及大环内酯类的耐药率均在80.0%以上。MHT和mCIM试验中有33株菌二者均为阳性,2株菌均为阴性,剩下5株MHT试验阳性而mCIM试验结果为阴性。32株菌携带KPC基因,未检出OXA-48及NDM-1基因。同源性分析结果显示40株CRKP分为7个型别,其中A型34株(占85%),B、C、D、E、F及G型各1株(各占2.5%)。
      结论分离的CRKP以携带KPC-2基因为主,共有7个型别,以A型为主,为有效治疗和预防CRKP感染提供了参考依据。

       

      Abstract:
      ObjectiveTo explore the drug resistance genes of carbapenem-resistant Klebsiella pneumonia(CRKP), and its homology analysis.
      MethodsForty strains of Klebsiella pneumonia were isolated from clinical samples from April to June 2018, and the drug sensitivity of which was identified using VITEK 2 COMPACT automatic bacterial sensitivity instrument.The carbapenem phenotypes of the 40 strains of Klebsiella pneumonia were screened using the modified hodge test(MHT) and modified carbapenem inactivation test(mCIM).PCR method was used to detect the main carbapenem resistance genes(including KPC, OXA-48 and NDM-1 genes).Matrix assisted laser desorption ionization time of flight mass spectrometry(MALDI-TOF MS) was used to analyze the homology of genes.
      ResultsThe 40 strains of CRKP were isolated from ICU ward(55%), mainly from respiratory tract samples(80%), and the resistance rates of those to cephalosporins, aminoglycosides and macrolides were above 80%.Thirty-three strains were positive in MHT test and mCIM test, 2 strains were negative in MHT test and mCIM test, and the remaining 5 strains were positive in MHT test and negative in mCIM test.The KPC gene was detected in 32 strains, and the OXA-48 and NDM-1 genes were not detected.The results of homology analysis showed that 40 strains of CRKP were divided into 7 types, which included type A in 34 strains(85%), and type B, C, D, E, F and G in 1 strain, respectively(each accounting for 2.5%).
      ConclusionsThe KPC-2 gene is the main genotype in CRKP, which can be divided into 7 kinds of types(type A as the main type).The study can provide the basis in effective treating and preventing the CRKP infection.

       

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