腹腔感染患者大肠埃希菌超广谱β-内酰胺酶及整合子研究  

Prevalence of extended-spectrum β-lactamases and integrons in Escherichia coli among patients with intra-abdominal infections

作　　者：胡志东[1] 胡巧娟[1] 田彬[1] 李静[1] 李金[1] 徐海茹[1] 杨华[1] 

机构地区：[1]天津医科大学总医院微生物免疫检验科,天津300052

出　　处：《临床检验杂志》2012年第1期54-56,共3页Chinese Journal of Clinical Laboratory Science

摘　　要：目的了解腹腔感染患者大肠埃希菌超广谱β-内酰胺酶(ESBLs)及Ⅰ、Ⅱ类整合子的分布情况。方法共收集分离自腹腔感染患者的大肠埃希菌62株,纸片扩散法测定16种抗菌药物敏感性,采用纸片协同扩散法检测ESBLs表型,PCR检测blaCTX-M、blaSHV、blaTEM及Ⅰ、Ⅱ类整合子基因,整合子阳性菌株进一步检测整合子的可变区基因盒。结果大肠埃希菌对碳青霉烯类、哌拉西林/他唑巴坦100%敏感,对复方磺胺甲噁唑耐药率最高(62.9%)。30株大肠埃希菌产ESBLs,其中基因型blaCTX-M-14、blaCTX-M-3、blaTEM-1、blaCTX-M-14+TEM-1分别检出16株、4株、3株、7株。未发现携带SHV型ESBLs菌株。有40株(64.5%)大肠埃希菌携带Ⅰ类整合子,其中1株同时携带Ⅰ、Ⅱ类整合子,共扩增出7种耐药基因盒组合形式。最常见的基因盒组合为dfrA17-aadA5,其次为dfrA12-orfF-aadA2,Ⅱ类整合子携带dfrA1-sat1-aadA1。结论腹腔感染大肠埃希菌主要携带blaCTX-M-14和blaTEM-1,Ⅰ类整合子的存在非常普遍,主要介导对氨基糖苷类及磺胺类耐药。Objective To investigate the prevalence of extended-spectrum β-lactamases （ESBLs） and class Ⅰ and Ⅱintegrons in Escherichia coli among the patients with intra-abdominal infections （IAIs）. Methods Sixty-two strains of Escherichia coli were isolated from the patients with IAIs. The disc diffusion test was conducted to detect the antimierobial susceptibility of 16 drugs. ESBL phenotype was identified by using double-disc synergy test. The presence and characterization of class Ⅰ and Ⅱ integrons, as well as the genes encoding blacTx_M, blasnv, blaTEM were detected by PCR and sequenced. The variable region gene cassettes of integrons-positive strains were then detected. Results Carbapenems and piperacillin/tazobactam were 100% sensitive against the isolates in this study, and strimethopritrdsulfa showed the highest drug-resistence （ 62.9% ）. Thirty of the 62 Escherichia coli isolates were ESBL phenotype- positive. Sixteen isolates harbored only blacTx_M_14, 4 carried blacTX_M_3 , 3 carried blaTEM.1 , and 7 carried blacTX_M.14 and blaTEM_l genes. None of the isolates contained the blasuv gene. Class I integron was detected in 40 （64.5%） isolates, and 1 isolate harbored both class I and II integrons. Seven different cassettes arrangements were identified, and dfrA17-aadA5 was the most prevalent, followed by dfrA12- orJF-aa＆42. The isolates containing class II integron harbored the dfrAl-satl-aadA1 gene cassette array in its variable region. Conclusion In this study the most common types of ESBLs identified in Escherichia coli with IAIs were blacTX_M_14 and blaTEM_l. A high prevalence of class I integrons was detected in Escherichia coli of IAIs, which mainly confers resistance to aminoglycosides and sulfonamides.

关 键 词：腹腔感染 大肠埃希菌 超广谱Β-内酰胺酶 整合子 

分 类 号：R446.5[医药卫生—诊断学]