碳青酶烯类耐药肺炎克雷伯菌耐药基因检测及同源性分析

Detection of Resistance Genes and Homology Analysis on Carbapenem-resistant Klebsiella Pneumonia

关键词:  碳青霉烯类耐药  肺炎克雷伯菌  耐药基因  同源性分析

Key words:  carbapenem-resistance  Klebsiella pneumoniae  resistance genes  homology analysis

摘要:

目的 探讨浙江省台州医院分离的碳青霉烯类耐药肺炎克雷伯菌（carbapenem-resistant Klebsiella pneumonia，CRKP）的耐药基因分型，并进行同源性分析。方法 收集浙江省台州医院2017年1月-2017年11月临床分离非重复的41株CRKP，用VITEK-compact2全自动微生物分析仪进行鉴定及药敏试验，质谱仪VITEK MS和纸片扩散法（K-B法）分别对鉴定、药敏进行复核；采用表型筛选试验对试验菌进行产A、B类碳青霉烯酶筛选；PCR检测耐药基因型；目的产物经基因测序和BLAST网上比对确定其基因型；脉冲场凝胶电泳（pulsed field gel electrophoresis，PFGE）分析41株菌株同源性。结果 表型筛选试验提示41株CRKP均产碳青霉烯酶；检出bla_KPC、bla_IMP、bla_NDM基因阳性率分别为95.12%（39/41），4.88%（2/41），2.44%（1/41），未检测到bla_SIM、bla_SPM、bla_VIM、bla_GIM基因；测序结果bla_KPC、bla_NDM、bla_IMP基因型别为bla_KPC-2、bla_NDM-1、bla_IMP-4；PFGE结果可分为A~N共14个谱型，以A型41.46%（17/41）、B型21.95%（9/41）、C型9.76%（4/41）为主，A型主要分布于神经外科，B型、C型主要分布于重症医学科。结论 浙江省台州医院CRKP耐药基因型以bla_KPC-2为主，且存在克隆株传播。医院感染控制部门及临床各科室应引起重视，采取有效措施，控制耐药株的传播。

Abstract:

OBJECTIVE To analyze the distribution of resistance gene and homology of carbapenem-resistant Klebsiella pneumoniae(CRKP) isolated from Taizhou Hospital of Zhejiang province. METHODS A total of 41 non-repetitive CRKP isolated were collected from Taizhou Hospital of Zhejiang province from January 2017 to November 2017. VITEK-compact 2 automatic microbial system was used for species identification and antimicrobial susceptibility test(AST), and the further confirm were performed by mass spectrometer VITEK MS and disc diffusion method(K-B method). The screening of A-and B-class carbapenemase phenotypes were tested by phenotypic screening test. The drug-resistant genotypes were detected by PCR and the genotypes were identified by gene sequencing and BLAST comparison. The homology of all 41 strains were analyzed using pulsed field gel electrophoresis(PFGE). RESULTS Phenotypic screening tests showed that all 41 strains of CRKP produced carbapenemase. The rates of bla_KPC, bla_IMP and bla_NDM genes were 95.12%(39/41), 4.88%(2/41) and 2.44%(1/41), respectively. Genes of bla_SIM, bla_SPM, bla_VIM and bla_GIM were not detected in all strains. Sequencing results indicated that bla_KPC-2, bla_NDM-1 and bla_IMP-4were the most popular sub-types in bla_KPC, bla_NDM and bla_IMP. Strains could be divided into A-N subcluster by PFGE. Type A(17/41, 41.46%), type B(9/41, 21.95%) and type C(4/41, 9.76%) were the main spectrum types. Type A was mainly distributed in Neurosurgery Department, type B and C were mainly in Department of Critical Care Medicine. CONCLUSION bla_KPC-2 is the main carbapenem-resistant gene of CRKP in Taizhou hospital of Zhejiang province, and exist clonal spread. Hospital infection control departments and clinical departments shall pay attention and take effective measures to control the spread of drug-resistant strains.