沙雷菌耐药性分析及其β-内酰胺酶基因型检测  

Analysis of drug resistance and detection of beta-lactamase genotypes in Serratia marcescens

作　　者：沈凌炜[1] 李丽红[1] 徐志江[1] 周宏伟[1] 张嵘[1] 陈功祥[1] 

机构地区：[1]浙江大学医学院附属第二医院检验科,杭州310009

出　　处：《临床检验杂志》2007年第5期330-332,共3页Chinese Journal of Clinical Laboratory Science

摘　　要：目的了解沙雷菌对临床常用抗生素的耐药性以及β-内酰胺酶的产生情况。方法采用纸片扩散法对临床分离到的325株沙雷菌进行药敏试验;三维试验对提取的沙雷菌酶粗提液进行β-内酰胺酶表型筛选;用特异性KPC引物进行PCR扩增并测序,确认黏质沙雷菌β-内酰胺酶的类型。结果沙雷菌对喹诺酮类和氨基糖苷类抗生素耐药率较低;对青霉素类、头孢菌素类、单酰胺类和含酶抑制剂等抗生素耐药率较高;对碳青霉烯类抗生素(亚胺培南)耐药率高达33.9%。特异性PCR和测序证实耐亚胺培南沙雷菌的β-内酰胺酶为KPC-2型碳青霉烯酶,三维试验中克拉维酸、EDTA和氯唑西林均不能抑制该酶对亚胺培南的水解活性。结论沙雷菌对临床常用抗生素有较高的耐药率,KPC-2酶是引起沙雷菌对碳青霉烯类抗生素耐药的主要原因。Objective To investigate the resistance to common antibiotics and the production of beta-lactamase in Serratia marcescens. Methods Antibiotic susceptibilities of 325 Serratia marcescens isolates were determined by disk diffusion method. The phenotypes of beta-lactamase were screened by three-dimensional test. PCR was preformed using specific KPC primers and DNA sequence was analysed to confirm the genotype of beta-lactamase. Results The resistance rates of Serratia marcescens to quinolones and aminoglycosides were low but high to penicillins,cephalosporins and monobactams. The resistance rate to carbapenems reached 33.9%. The presence of blaKPC-2 gene was confirmed by specific PCR and DNA sequence analysis. Both three-dimensional test and three-dimensional inhibition test showed that the KPC-2 enzyme activity against imipenem was not inhibited in the presence of clavulanic acid, EDTA or cloxacillin. Conclusions The resistance rate of Serratia marcescenswas to common antibiotics relatively high. Production of KPC-2 mainly contributed to reduced susceptibility of carbapenems, such as imipenem, to Serratia marcescens.

关 键 词：沙雷菌 耐药性 Β-内酰胺酶 

分 类 号：R446.5[医药卫生—诊断学]