Carba NP碳青霉烯酶检测方法在医院感染监测中的应用

Application of Carba NP carbapenemase detection in surveillance of nosocomial infections

目的研究Carba NP法检测3株产酶菌株同源性及耐药机制,探讨Carba NP碳青霉烯酶检测方法在医院感染监测中的应用价值,为临床治疗提供参考依据。方法于2012年7月-2013年1月采用Carba NP法对检出3株产碳青霉烯酶克雷伯菌属细菌进行鉴定、药物敏感性、菌株特征及药物敏感谱;PCR扩增和测序碳青霉烯酶的基因型;PFGE电泳探讨3株菌的亲缘关系。结果菌株1为肺炎克雷伯菌,产碳青霉烯酶酶KPC-2;菌株2为肺炎克雷伯菌,产碳青霉烯酶IMP-4,菌株3为产酸克雷伯菌,同时产KPC-2和IMP-4;PFGE结果表明该3株菌不是近源的克隆株,提示KPC-2和IMP-4基因元件在该病房的跨种属传播。结论 Carba NP能早期迅速准确的检出菌株是否产碳青霉烯酶,为产碳青霉烯酶菌株的医院感染提供早期线索,在医院感染监测、控制中有重要应用价值,结合PCR及测序,PFGE的结果能在医院获得性感染控制方面发挥积极的作用。

OBJECTIVE To describe the application of Carba NP method in diagnosis of carbapenemase‐producing strains ,and to investigate the value of this method in surveillance of nosocomial infection so as to provide reference for clinical treatment .METHODS The Carba NP method was used to detect 3 strains of carbapenemase‐producing K lebsiella during Jul .2012 to Jan .2013 in the hospital .Species identification and drug susceptibility test was done by BD bacterial identification system and 16S rDNA sequencing .PCR amplification and sequencing further verified the gene type of carbapenemases .PFGE techniques analyzed the homology of the three strains .RESULTS Strain 1 was K lebsiella pneumonia producing carbapenemase KPC‐2 .Strain 2 was K . pneumonia producing carbapenemase IMP-4. Strain 3 was K. oxytoca producing both KPC-2 and IMP-4. PFGE reveals that the three iso- lates were not homologus, suggesting there existed cross-species spread of the gene elements KPC-2 and IMP-4 in the ward. CONCLUSION Carba NP method can rapidly and accurately detect carbapenemase-producing isolates in the early stage, which provides early evidence for nosocomial infection caused by carbapenemase-producing strains and is valuable for the supervision and control of nosocornial infection. Combined with PCR and sequencing, PFGE can promote the control of hospital acquired infection.