烧伤患者感染耐药鲍氏不动杆菌β-内酰胺酶与膜孔蛋白编码基因研究

Research onβ-lactamase gene and outer membrane protein encoding genes in drug-resistant Acinetobacter baumannii causing infections in burn patients

目的了解烧伤患者分离耐药鲍氏不动杆菌β-内酰胺酶和膜孔蛋白CarO、oprD2基因的存在状况,以探讨鲍氏不动杆菌耐药的分子水平依据。方法 20株耐药鲍氏不动杆菌均分离自2012年10月-2013年8月医院住院烧伤患者,采用GNS-448药敏卡及K-B法测定抗菌药物的敏感性,聚合酶链反应(PCR)检测34种β-内酰胺酶和膜孔蛋白CarO,oprD2基因,数据采用SPSS 15.0软件进行统计分析。结果 20株鲍氏不动杆菌对12种常用抗菌药物严重耐药,对头孢唑林、头孢噻肟和头孢西丁的耐药率达100.0%;20株耐药鲍氏不动杆菌β-内酰胺酶编码基因检出率,blaTEM-1为10.0%、blaADC为100.0%、blaOXA-2群为95.0%、blaOXA-24群为5.0%、blaOXA-23群为95.0%、blaOXA-66群为95.0%;耐药株与SDF株的OprD2蛋白分子立体结构存在4个氨基酸的变异。结论医院分离的20株耐药鲍氏不动杆菌存在β-内胺酶基因blaADC变异型、blaOXA-23和blaOXA-66,与SDF株的OprD2蛋白分子立体结构存在明显差异。

OBJECTIVE To investigate the presence of β‐lactamase genes and membrane protein CarO ,op rD2 genes in drug‐resistant A cinetobacter baumannii isolated from the burn patients so as to explore the drug resistance of the A .baumannii on the molecular level .METHODS A total of 20 strains of drug‐resistant A .baumannii were isolated from the burn patients who were hospitalized from Oct 2012 to Aug 2013 ,the drug susceptibility testing was per‐formed by using GNS‐448 drug susceptibility card and K‐B method ,and 34 types of β‐lactamase genes and mem‐brane protein CarO ,op rD2 genes were detected by polymerase‐chain‐reaction（PCR） ,and the statistical analysis of data was performed with the use of SPSS 15 .0 software .RESULTS The 20 strains of A .baumannii were highly re‐sistant to the 12 commonly used antibiotics ,and the drug resistance rates to cefazolin ,cefotaxime ,and cefoxitin reached to 100 .0% .The detection rates of the β‐lactamase genes including blaTEM‐1 ,blaADC ,blaOXA‐2 group ,blaOXA‐24 group ,blaOXA‐23 group ,and blaOXA‐66 group were 10 .0% ,100 .0% ,95 .0% ,5 .0% , 95 .0% ,and 95 .0% respectively .The three‐dimensional structure of OprD2 protein molecules of the drug‐resist‐ant strains and the SDF strains had four amino acid variations .CONCLUSION The β‐lactamase genes including blaADC variant ,blaOXA‐23 ,and blaOXA‐66 exist in the 20 drug‐resistant A .baumannii isolates ,which vary sig‐nificantly to the SDF strains in the three‐dimensional structure of op rD2 protein molecules .