耐含酶抑制剂抗菌药物的肺炎克雷伯菌耐药表型及基因型研究

目的研究含酶抑制剂抗菌药物头孢哌酮/舒巴坦(CFS)和(或)哌拉西林/他唑巴坦(TZP)耐药的肺炎克雷伯菌耐药性和耐药基因。方法收集浙江大学医学院附属第一医院细菌室2006年4~6月分离非重复肺炎克雷伯菌75株,用琼脂稀释法检测12种抗菌药物的最低抑菌浓度,用含1μg/ml头孢噻肟平板法和纸片确证试验做为表型超广谱β-内酰胺酶(ESBLs)筛选;采用聚合酶链反应(PCR)、PCR产物测序、等电聚焦电泳检测其等电点、接合试验等方法明确基因型。结果75株肺炎克雷伯菌中共检测到CFS和(或)TZP耐药20株,表现为多药耐药且均检出β-内酰胺酶基因,其中15株(75.0%)携带CTX-M型基因,14株(70.0%)携带≥2种基因,3株(15.0%)产KPC-2碳青酶烯酶肺炎克雷伯菌高度耐药;11株(55.0%)产ESBLs同时产TEM-1型广谱酶,4株(20.0%)同时携带CTX-M、TEM和SHV基因。结论酶抑制剂耐药肺炎克雷伯菌存在多种耐药基因,表现为多药耐药。

Phenotype and Genotype of Klebsiella pneumoniae Isolates Resistant to Enzyme Inhibitors

OBJECTIVE To study the phenotype and genotype of CFS-and/or TZP-resistant Klebsiella pneumoniae.METHODS The lasting and non-repeating clinical strains of K.pneumoniae were collected from ward.Plasmid conjugation,PCR amplification,gene cloning and DNA sequencing,isoelectric focusing electrophoresis (IEF),and initial screen and confirmatory test were carried out for analyzing the encoding gene ofβ-lactamase. RESULTS Seventy-five clinical strains of K.pneumoniae were collected,20 strains confirmed to resist to CFS and/or TZP.and produce genotype of β-lactamases.CTX-M was the most common type(75.0%),14 isolates (70.0%) carried two or more types of ESBLs,and 3 isolates(15.0%) produced class A carbapenemase KPC-2,11 isolates(55.0%) carried ESBLs and TEM-1,and 4 isolates(20.0%) carried CTX-M、SHV and TEM.CONCLUSIONS K.pneumoniae resistant to enzyme inhibitors contains an array of drug resistance gene and expresses multi-drug resistance.