大肠埃希菌高产AmpC酶的检测及耐药性分析

目的了解深圳市人民医院高产AmpC酶大肠埃希菌的存在现状及其耐药性。方法采用Tris-ED-TA纸片裂菌法检测148株大肠埃希菌的AmpC酶。用琼脂稀释法测定产酶株对11种抗生素的最低抑菌浓度（MIC）。结果 148株大肠埃希菌中6株检出AmpC酶,检出率为4.1%。所有产AmpC酶大肠埃希菌对亚胺培南敏感,MIC为0.12～0.25μg/ml;对头孢吡肟的MIC值也较低,为0.5～32.0μg/ml,仅1株耐头孢吡肟。所有产AmpC酶大肠埃希菌对头孢西丁耐药,MIC为32～128μg/ml;对氨苄西林/舒巴坦、阿莫西林/克拉维酸和哌拉西林/他唑巴坦等加酶抑制剂复合物耐药性较强。结论深圳市人民医院大肠埃希菌高产AmpC酶检出率为4.1%。产酶株对多种抗生素耐药性较高。

Detection and antibiotic resistance analysis of Escherichia coli with AmpC β-lactamase hyperproduction

Objective To understand the occurrence and antibiotic resistance of Escherichia coli with AmpC β-lactamase hyperproducton in Shenzhen People＇s Hospital. Method Detection of AmpC β-lactamase in 148 Escherichia coli isolates was carried out with Tris-EDTA disk test. Minimal inhibitory concentrations（MIC） of 11 antibiotics to the isolates were determined by the agar dilution method.Result 6 of 148 Escherichia coli isolates were found producing AmpC β-lactamase,with the detection rate of 4.1%.All of these AmpC producing isolates showed susceptibility to imipenem（MIC 0.12 to 0.25 μg/ml）.The MIC of cefepime was 0.5 to 32.0 μg/ml and only one isolate was resistant to it.All the AmpC β-lactamase producers were resistant to cefoxitin （MIC 32 to 128 μg/ml）.They also appeared to be resistant to β-lactamase inhibitor combinations,such as ampicillin/sulbactam,amoxicillin/clavulanic acid and piperacillin/tazobactam.Conclusion 4.1% of Escherichia coli isolates detected in Shenzhen People＇s Hospital were AmpC β-lactamase hyperproducers,which show strong resistance to a variety of antibiotics.