同一患者不同部位的4株肺炎克雷伯菌对碳青霉烯类抗生素耐药机制研究和同源性分析  

The carbapenem-resistance mechanism and homology analysis of four strains of Klebsiella pneumoniae isolated from different sites of one patient

作　　者：刘瑛[1] 俞静[1] 张良[2] 沈立松[1] 

机构地区：[1]上海交通大学医学院附属新华医院检验科,上海200092 [2]上海交通大学医学院附属新华医院泌尿外科,上海200092

出　　处：《中国感染与化疗杂志》2013年第6期460-464,共5页Chinese Journal of Infection and Chemotherapy

基　　金：上海市卫生局资助课题(2010024)

摘　　要：目的对临床分离自同一患者不同部位的4株耐碳青霉烯类抗生素肺炎克雷伯菌进行耐药机制研究和同源性分析。方法收集2012年3月上海新华医院临床微生物实验室从1例膀胱癌术后患者的血、尿、痰和盆腔引流液标本中分离得到耐碳青霉烯类抗生素肺炎克雷伯菌4株。分别采用:①改良Hodge试验筛选碳青霉烯酶;②PCR方法及基因测序检测耐药基因;③SDS-PAGE分析菌株外膜蛋白的改变等方法进行耐药机制研究。并采用ERIC-PCR方法进行DNA同源性分析。结果改良Hodge试验显示4株耐碳青霉烯类抗生素肺炎克雷伯菌均产碳青霉烯酶,通过PCR方法及基因测序确证皆产KPC-2酶。SDS-PAGE分析结果显示4株细菌的外膜蛋白表达不同于碳青霉烯类抗生素敏感型肺炎克雷伯菌。ERIC-PCR基因图谱显示此4株细菌的DNA指纹图谱完全一致。结论本研究中的4株耐碳青霉烯类抗生素肺炎克雷伯菌的主要耐药机制为产KPC-2酶以及外膜蛋白异常引起的外膜蛋白通透性改变,且这4株细菌为同一克隆株。Objective To study the drug resistance mechanism and homologous relationship of four clinical strains of carbapen em resistant Klebsiella pneurnoniae isolated from different sites of the same one patient. Methods Four earbapenem-resistant K. pneurnoniae strains were isolated from blood, urine, sputum and pelvic drainage of a patient after cystectomy in clinical mi crobiology lab of Xinhua Hospital in March 2012. ① Modified Hodge test was used to detect the expression of carbapenemase. ②PCR amplification assay and DNA sequencing were used to detect resistance related genes. ③ SD-PAGE analysis was per-formed to analyze outer membrane porin components of the four carbapenera resistant K. pneumoniae isolates. ERIC PCR as say was used to analyze the homology of these carbapenem-resistant isolates. Results Modified Hodge test demonstrated that all the four carbapenem-resistant K. pneurnoniae expressed carbapenemase. KP@2 gene was identified in all the four isolates by P（＇R test and I）NA sequencing. SD＆PAGE analysis indicated an outer membrane porin alteration common to all the four iso lates which is distinct from that of the strain sensitive to antibiotics. The identical DNA fingerprinting of the four strains was confirmed by ERIC PCR analysis. Conclusions The antibiotic resistance mechanism of the four carbapenem resistant K. pneumoniae associated with this case includes the expression of KPG-2 and altered outer membrane permeability induced by abnormal expression of outer membrane porln. These four strains belong to one common clonal group.

关 键 词：肺炎克雷伯菌 碳青霉烯酶 外膜蛋白 

分 类 号：R446.5[医药卫生—诊断学]