耐碳青霉烯肺炎克雷伯菌的耐药机制及流行特征研究

目的 研究医院耐碳青霉烯类抗生素耐药肺炎克雷伯菌的耐药机制和分子同源性,为医院感染的预防和控制提供可靠的研究基础.方法 收集临床分离的碳青霉烯类抗生素耐药肺炎克雷伯菌;琼脂稀释法测定抗生素最低抑菌浓度(MIC);PCR特异扩增和序列比对分析研究细菌对碳青霉烯类抗生素耐药的分子机制及流行特征.结果 分离碳青霉烯类抗生素耐药的肺炎克雷伯菌共189株,均为产blaKPC-2肺炎克雷伯菌,其对美罗培南、亚胺培南和厄他培南的MIC范围分别为2~128mg/L、4~128mg/L、4~128mg/L.其中5株细菌同时产blaVIM-1.ERIC分型显示189株细菌分为a型、b型,其中a型较多(67.9%).结论 院内可能有过携带blaKPC-2的肺炎克雷伯菌引起的医院内暴发流行,需要加强消毒隔离,防止进一步播散.

Objective To investigate the mechanism of reduced susceptibility to carbapenems of Klebsiella pneumoniae and its homology.Methods The clinical isolates of carbapenem-resistant Klebsiella pneumoniae were collected,The minimum inhibitory concentration(MIC)of antibiotics was determined by agar dilution method.The molecular mechanism and epidemiological characteristics of carbapenem-resistant bacteria were analyzed by PCR-specific amplification and sequence alignment.Results A total of 64 carbapenem-resistant Klebsiella pneumoniae strains were isolated.All of them were BlaKPC-2-producing Klebsiella pneumoniae.The MIC ranges of meropenem,imipenem and ertapenem were 2~128mg/L,4~128mg/L,4~128mg/L,respectively.2 strains of bacteria produce blaVIM-1 simultaneously.ERIC typing showed that 64 strains of bacteria were classified into type A and B,among which type A was more(67.9%).Conclusion Hospital outbreaks caused by Klebsiella pneumoniae carrying blaKPC-2 may have occurred in hospitals,and disinfection and isolation should be strengthened to prevent further dissemination.