大肠埃希菌产超广谱β-内酰胺酶的基因型研究及耐药分析

Research on genotype and drug resistance of extended spectrumβ-lactamase produced in Escherichia coli

目的探究贵州黔西南州大肠埃希菌产超广谱β-内酰胺酶(ESBLs)的基因型及耐药率。方法收集样本,从512个样本中选取大肠埃希菌共208例,对株菌行ESBLs表型确证,再对确证的产ESBLs大肠埃希菌行基因型检测,并对菌株行耐药检测。结果在208株大肠埃希菌中,其中ESBLs大肠埃希菌共有61株,阳性率为29.33%;产ESBLs对哌拉西林、氨苄西林、头孢唑林、头孢呋辛、头孢噻肟、头胞哌酮/舒巴坦和头胞噻肟/舒巴坦的耐药率明显高于非产ESBLs菌株(均P<0.05),产ESBLs大肠埃希菌对美罗培南和亚胺培南耐药率均表现为0;PCR法检测最常见基因型为CTX-M-1型ESBLs,检出率为6.55%。部分菌株同时产2种ESBLs。结论 ESBLs细菌检出率高,对美罗培南和亚胺培南的耐药,基因以CTX-M-1为主,其次是CTX-M-9。

Objective To investigate the genotype and drug resistance rate of extended spectrum β- lactamase produced in Escherichia coli. Methods 208 strains of Escherichia coli were collected from 512 samples,and the phenotype confirmatory of them was performed; The genotype and drug resistance of the confirmed E. coli producing ESBLs were detected. Results In208 strains of E. coli,61 were defined as ones producing ESBLs,and the positive rate of E. coli was 29. 33%. The drug resistance rate of ESBLs- producing strains to most antibiotics（ piperacillin,ampicillin,cefazolin,cefuroxime,cefotaxime,cefoperazone / shubatan head cell and the first cell of cefotaxime / sulbactam） was significantly higher than in non- ESBLs producing strains（ all P 〈 0. 05）. The drug resistance rates of ESBLs- producing E. coli to meropenem and imipenem were 0%. The most frequent β- lactamase type was cefotaximase one（ CTX- M- 1,6. 55%）. Parts of strains could simultaneously produce2 kinds of ESBLs. Conclusion The detection rate of ESBLs strains was higher,the drug resistance to meropenem and imipenem,CTX- M- 1 was major in the genes,followed by CTX- M- 9.