危重病房耐碳青霉烯酶鲍曼不动杆菌同源性研究

To study the homogeneity of carbapenems resistant Acinetobacter baumannii in ICU

目的探讨杭州市第一医院危重病房耐碳青霉烯酶鲍曼不动杆菌之间的同源性,进行分子流行病学调查,旨在为制定预防和控制其院内感染的措施提供依据。方法收集该院危重病房2005年1月至12月分离到的34株亚胺培南耐药鲍曼不动杆菌。采用全自动微生物分析系统VITEK-AMS60对34株耐碳青霉烯酶鲍曼不动杆菌进行鉴定及药敏;用琼脂稀释法和E-test法测定14种抗菌药物的最低抑菌浓度(MIC),脉冲场凝胶电泳(PF-GE)分析其耐药株的同源性,对碳青霉烯类基因OXA-23型、OXA-24型、IMP型、VIM型基因进行PCR扩增及序列分析。结果PFGE发现34株鲍曼不动杆菌菌株为同一耐药克隆株,在危重病房呈爆发流行。所有对亚胺培南耐药鲍曼不动杆菌明确产OXA-23型碳青霉烯酶,未检出OXA-24、IMP、VIM基因型。34株菌株质粒提取未成功。结论该院同一个耐药克隆株在危重病房不同患者身上流行,可能与行气管插管、呼吸机、氧气湿化瓶、护士手操作有关。

Objective To investigate the homogeneity and molecular epidemiology of carbapenems resistance gene in Acinetobacter baumannii from intensive care unit of the First People＇ s Hospital of Hangzhou, and to offer evidence for establishing the measure to prevent and control hospital onset of infection. Methods Collected 34 strains of imipenem resistant Acinetobacter baumannii from 2005.1 to 2005.12 in ICU of our hospital. The identification and antimicrobial susceptiblity test of Acinetobacter baumaniis were done using VITEK-AMS60. The minimum inhibitory concentrations（MIC） were examined by agar dilution method. The homology of the resistance isolates was examined by pulsed field gel electrophoresis （PFGE）. The drug resistant genes including OXA-23, OXA-24, IMP, VIM were amplified and sequenced. Results 34 strains were found that they were the same clone strains by PFGE, which occur epidemic outbreak in ICU. All the 34 imipenem resistance isolates produced OXA-23 and no OXA-24, IMP, VIM were detected. No plasmid was extracted from 34 isolates. Conclusion The same clone strains prevailed on different patients in ICU maybe relateed to using tracheal intubation, respirator, the humidification bottle of oxygen and the nurses＇ hands operating.