OXA-23基因和外膜蛋白介导鲍曼不动杆菌对碳青霉烯类药物耐药的机制分析  

Analysis of the mechanism of Acinetobacter baumannii resistance to carbapenem mediated by OXA-23 gene and outer membrane proteins

作　　者：姜飞[1] 邓丽华[2] 施德仕[2] 康海全[2] 赵晓杰[1] 马萍[1,2] 李洪春[1,2] 

机构地区：[1]徐州医学院医学技术学院,江苏徐州221004 [2]徐州医学院附属医院检验科,江苏徐州221002

出　　处：《临床检验杂志》2014年第10期784-787,共4页Chinese Journal of Clinical Laboratory Science

基　　金：徐州市科技局资助项目(XZXD1326)

摘　　要：目的分析碳青霉烯类耐药鲍曼不动杆菌(CRAB)的耐药性、耐药基因及外膜蛋白的表达情况。方法收集徐州医学院附属医院CRAB 64株,药敏试验采用琼脂稀释法,改良Hodge试验和酶粗提取液水解底物法检测碳青霉烯酶,EDTA-Na2双纸片协同试验检测金属β-内酰胺酶,PCR法检测主要的碳青霉烯酶基因,PCR产物进行DNA测序分析,肠杆菌科基因间重复一致性序列PCR(ERIC-PCR)进行同源性分析,接合试验探讨耐药基因的可传递性,采用十二烷基硫酸钠-聚丙烯酰胺凝胶电泳(SDS-PAGE)分析菌株外膜蛋白的表达。结果 64株CRAB仅对多黏菌素B保持良好的敏感性(100%);改良Hodge试验结果为阴性,酶粗提液水解底物法结果显示弱阳性;EDTA-Na2双纸片协同试验呈阴性;与敏感菌株相比,CRAB全部扩增出OXA-23基因;同源性分析将其分为4型,Ⅰ型为主要流行株(40株),其中30株来源于重症监护病房(ICU);接合试验未获成功;外膜蛋白分析发现,CRAB主要改变为缺失相对分子质量(Mr)27 000的蛋白质条带和出现Mr 30 000新蛋白质条带。结论本院ICU病区存在CRAB的克隆流行,其耐药机制可能与OXA-23基因的表达及外膜蛋白的缺失与新增有关。Objective To investigate the resistance, resistant genes and the expression of outer membrane proteins （OMP） of carbapenem-resistant Acinetobacter baumannii （CRAB）. Methods Sixty-four CRAB strains from the Affiliated Hospital of Xuzhou Medical College were collected, and their antibiotic sensitivity was detected by the agar dilution method, carbapenemase by the modified Hodge test and crude enzyme solmion hydrolysis substrate method, metallo-[3-1actamase （MBL） by the EDTA-Na2-disk synergy test, main carbapenemase genes by PCR and DNA sequencing, homology analysis by the enterobacteriaceae repetitive intergenic consensus （ERIC）-polymerase chain reaction （PCR）, the transmission of resistant genes by the conjugation test, and the expression of OMP by the sodium dodecyl sulfate （SDS）-polyacrylamide gel electrophoresis （PAGE）. Results All of 64 CRAB strains were sensitive to polymyxin B （ 100% ） , and had negative modified Hodge test and EDTA-Na2-disk synergy test and weakly positive crude enzyme solution hydrolysis substrate test. Compared with earbapenem-sensitive strains, all of CRAB strains were detected OXA-23 gene by PCR. ERIC- PCR showed that all of CRAB strains could be divided into 4 types, and 40 strains belonged to type I, in which 30 were from intensive care units （ICU）. The conjugation test failed. OMP analysis showed that a protein with a relative molecular mass （Mr） of 27 000 was absent and a new protein with a Mr of 30 000 present. Conclusion There was an epidemic of CRAB in the ICU of the Affiliated Hospital of Xuzhou Medical college, and the development of CRAB might be related to the expression of OXA-23 gene and the loss and appearance of OMP.

关 键 词：鲍曼不动杆菌 碳青霉烯类 OXA-23基因 外膜蛋白 耐药 

分 类 号：R446.5[医药卫生—诊断学]