碳青霉烯类耐药肺炎克雷伯菌分子流行病学和耐药基因分析

Analysis of carbapenem resistant Klebsiella pneumoniae molecular epidemiology and antibiotic resistance gene

目的：探究徐州医学院附属医院临床分离的耐碳青霉烯类肺炎克雷伯菌的分子流行病学特征及耐药基因。方法收集并鉴定该院2013年2～12月临床分离非重复碳青霉烯类耐药肺炎克雷伯菌株55株。肠杆菌基因间重复性共有序列（ERIC）‐聚合酶链反应（PCR）分析菌株的分子流行病学特征。药敏试验采用琼脂稀释法，改良 Hodge 方法检测碳青霉烯酶，亚胺培南＋乙二胺四乙酸双纸片协同法检测金属β‐内酰胺酶，PCR 方法检测细菌携带的耐药基因。结果 ERIC‐PCR 将55株肺炎克雷伯菌分为4型，以Ⅰ型为主，共41株。55株肺炎克雷伯菌对除多黏菌素和替加环素外的其他抗菌药物显示了较高的耐药性。改良 Hodge 试验阳性43株，金属酶检测试验结果均为阴性。 PCR 结果显示，K PC‐2型44株，CTX‐M‐9型27株，S HV 型22株， TEM 型23株，其中有25株同时携带3种或3种以上的耐药基因。结论该院分离的碳青霉烯类耐药肺炎克雷伯菌对临床大多数常用抗菌药物显示较高水平的耐药性；其耐药机制主要是 K PC‐2碳青霉烯酶，CTX‐M‐9、S HV 和 TEM 型β‐内酰胺酶同时参与其多重耐药机制。

Objective To investigate the molecular epidemiology characteristics and drug resistance genes of imipenem‐resistant Klebsiella pneumoniae isolated from the Affiliated Hospital of Xuzhou Medical College .Methods A total of 55 strains of carbapen‐em resistant Klebsiella pneumoniae were collected and identified from February to December in 2013 .Enterobacterial repetitive in‐tergenic consensus sequence （ERIC） polymerase chain reaction（PCR） analysis molecular epidemiology .Susceptibility testing for an‐tibiotics was performed by the disc diffusion method carbapenemase production was confirmed by modified Hodge test and MBL production by IPM /IPM‐EDTA combined disc test .The resistant genes were detected by PCR .Results ERIC‐PCR results showed that 55 strains of Klebsiella pneumoniae were divided into 4 types ,the main type was type Ⅰ ,41 strains belonged to type I .A total of 55 strains of bacteria showed a high level resistance to routine antibiotics except for colistin and tigecycline .A total of 43 strains were positive in modified Hodge test and all the 55 strains were negative to enzyme detection test .PCR results showed that 44 strains were of K PC‐2 type ,27 strains of CTX‐M‐9 type ,22 strains of S HV type ,23 strains of TEM type ,25 of them were carrying three or more drug resistant genes at the same time .Conclusion Klebsiella pneumoniae that resistant to carbapenem showed high levels of resistance to routine antibiotic in our hospital .Strains of carbapenem resistant Klebsiella pneumoniae appeared ,K PC‐2 was the main reason to cause the bacterial resistance to carbapenems ,CTX‐M‐9 type ,S HV and TEM type β‐lactamases were also in‐volved in the mechanism of multidrug resistance .