产ESBLs大肠埃希菌和肺炎克雷伯菌的检测及其基因分析  

Detection of Escherichia coli and Klebsiella pneumoniae producing extended-spectrum beta-lactamases and analysis of their genetypes

作　　者：邵剑春[1] 胡大春[1] 杨绍敏[1] 周玲[1] 李超[1] 刘德华[1] 

机构地区：[1]云南省昆明市临床疾病分子生物学重点实验室,昆明市第一人民医院检验科,650011

出　　处：《国外医学（临床生物化学与检验学分册）》2005年第12期872-876,共5页Foreign Medical Sciences(section of Clinical Biochemistry and Laboratory Medicine

摘　　要：目的了解临床分离菌中产超广谱β内酰胺酶(ESBLs)大肠埃希菌和肺炎克雷伯菌发生率,分析其耐药表型,探讨其ESBLs基因类别。方法采用美国国家临床实验室标准化委员会(NCCLS)推荐的纸片扩散法,对364株大肠埃希菌和71株肺炎克雷伯菌进行产ESBLs菌株初筛试验,并用双纸片确证试验和双纸片协同试验进行产ESBLs菌株确证。按照NCCLS文件标准,用KirbyBauer纸片扩散法进行产ESBLs株21种抗生素药敏试验。用PCR方法扩增168株ESBLs表型阳性菌中blaTEM1、blaSHV1、CTXM1组、TOHO1组等4种基因。结果(1)大肠埃希菌和克雷伯菌中产ESBLs的检出率分别为46.7%和32.4%。(2)产ESBLs菌对青霉素类100%耐药;对第1、2代头孢菌素耐药率达85%～100%;对除头孢他定以外的第3代头孢菌素,产ESBLs大肠埃希菌耐药率为80%以上,产ESBLs肺炎克雷伯菌耐药率为65%～75%以上;产ESBLs菌对复方新诺明的耐药率为75%～85%;产ESBLs大肠埃希菌对环丙沙星耐药率为80%～90%、庆大霉素耐药率为50%～75%;产ESBLs菌对阿米卡星、头孢替坦、亚胺培南有较好的敏感性(80%～90%以上)。(3)产ESBLs大肠埃希菌中,blaTEM1、blaSHV1、CTXM1组等3种基因扩增阳性率分别为93.9%、7.4%和53.4%。51.4%的菌株同时携带2种耐药基因,2.7%的菌株同时携带3种耐药基因。产ESBLs肺炎克雷伯菌中blaTEM1、blaSHV1、CTXM1组等3种基因扩增阳性率分别为50.0%、95.0%和20.0%。同时携带2种耐药基因的菌株占35.0%,同时携带3种耐药基因的菌株占15.0%。两种细菌中均未检出TOHO1组基因。结论大肠埃希菌和肺炎克雷伯菌中产ESBLs的检出率较高,大肠埃希菌中产ESBLs菌比例有逐年上升趋势。产ESBLs菌对头孢噻肟的耐药率远高于头孢他定,且多数菌株对青霉素类,第1、2、3代头孢菌素、喹诺酮类、磺胺类、氨基糖甙类等抗生素呈多重耐药。大肠埃希菌中以TEM型和CTXM型基因为主。肺炎克雷伯菌以SHV型基Objective To determine the prevalence, multidrugs resistance, and the genetypes of extended-spectrum beta-lactamases （ESBLs） among clinical isolates of Klebsiella pneumoniae and Escherichia coli. Methods 364 isolates of Escherichia coli and 71 isolates of Klebsiella pneumoniae isolated from a hospital in Kunming during the period from January 2002 to June 2004 were screened for ESBL production by disc diffusion methods as described by the NCCLS. ESBL-producing isolates were confirmed by double-disk synergy test and disc diffusion confirming test as recommended by the NC-CLS. The in vitro activities of 21 antimicrobial agents in the ESBL- producing isolates were determined by Kirby-Bauer method according to the NCCLS guidelines. PCR analysis was used for blaTEM-1, blaSHV-1 ,CTX-M1 group and TOHO-1 group genes present in 20 isolates Klebsiella pneumoniae and 148 isolates Escherichia coli. Results （1） The ESBL phenotype was detected in 170 （46.7%） E. coli and 23（32.4%） K. pneumoniae isolates. （2） The percentage of ESBL- producing organisms that were resistant against antibiotic was 100% for penicillins, 85%- 100 for the first and the second products of cephalosporin, 65 %-75 % for the third products of cephalosporin excluding ceftazidime, 75 %- 85% for trimethoprin/sulfamethoxozol, 50% - 75% for gentamicin, and 80% - 90% for ciprofloxacin. 80%-90 % of ESBL-producing isolates showed susceptibility to amikacin, cefotetan and imipenem. （3） The genes of blaTEM-1, blaSHV-1 and CTX-M-1 group were detected in 93.9% ,7.4% and 53.4% of ESBL-producing E. coil respectively, and in 50.0% ,95.0% and 20.0% of ESBL-producing K. pneumoniae respectively. The ESBL-producing organisms carried two of these genes were 51.4% of E. coil and 35.0% of K. pneumoniae. 15.0% of ESBL-producing K. pneumoniae carried all of these genes. The TOHO-1 group gene was not detected among both of E. coil and K. pneumoniae. Conclusion The prevalence of ESBLs among clinical isolates of Klebsiella pneumoniae and Escherichia coli was

关 键 词：埃希氏菌属 克雷伯菌属 Β内酰胺酶类 基因 

分 类 号：R446.5[医药卫生—诊断学]