产超广谱β-内酰胺酶大肠埃希菌的耐药表型及基因型研究

目的研究大肠埃希菌产超广谱β-内酰胺酸ESBLs耐药表型及基因型特性。方法2006年1月至2006年12月我院临床分离的大肠埃希菌125株。先后用标准纸片法筛选试验和确认试验、Etest条分别检测ES-BLs。聚合酶链反应(PCR)以及基因测序分析测定ESBLs基因的类型。结果125株大肠埃希菌中检出71株产ESBLs(56.8%)菌株。PCR结果显示,产ESBLs大肠埃希菌基因主要是CTX-M-14型为主;TEM基因型均为TEM-1型,SHV基因型均为SHV-1型。产ESBLs肺炎克雷伯菌对头孢曲松、头孢噻肟、左氧氟沙星耐药率在70%以上,对美罗培南,亚胺培南敏感性好。结论本地区大肠埃希菌ESBLs携带率较高,其基因以CTX-M-14型为主,其次CTX-M-3型ESBL,产酶株对多种抗菌药物耐药,对美罗培南、亚胺培南敏感性好。

Study of resistance phenotypes and genotypes of ESBLs-producing Escherichia coli

Objective: To study the resistance phenotypes and genotypes of Escherichia coli which produce ESBLs.Methods: One hundred and twenty five strains of Escherichia coli were collected in Taian Central Hospital between January 2006 and December 2006.ESBLs was identified by standard paper discscreening and affirming test and Etest.The genotypes of ESBLs were determined by PCR and gene sequencing analysis.Results: Seventy one of all strains were detected to be ESBLs-producing strains.The result of PCR showed that the main genotype of ESBLs-producing Escherichia coli was CTX-M-14,all TEM genotype was TEM-1 and all SHV genotype was SHV-1.The resistance rate of ESBLs strain to Ceftriaxone,Cefotaxime and Levofloxacin were more than 70%,but it was sensitive to Meropenem and Imipenem.Conclusion: The incidence of ESBLs-producing Escherichia coli carriers is very high.The main genotype is CTX-M-14 and then is CTX-M-3.ESBLs-producing strains are resistant to several antibiotics,except Meropenem and Imipenem.