从大肠埃希菌和肺炎克雷伯菌中检测超广谱β内酰胺酶和AmpC酶

目的研究大肠埃希菌和肺炎克雷伯菌的产酶情况及耐药模式,并对9种抗生素做药敏试验,比较产酶菌与非产酶菌对9种抗生素的耐药率,为临床治疗产酶菌感染提供理论依据。方法应用头孢西丁三相试验检测AmpC酶,采用美国国家临床实验室标准委员会(NCCLS)表型筛选和确认试验检测ESBLs菌株,以K-B琼脂扩散法做药敏试验。结果在110株大肠埃希菌和肺炎克雷伯菌中,6株(5.45%)产AmpC酶,20株(18.2%)产ESBLs,1株(0.90%)同时产AmpC酶和ESBLs。产酶株对亚胺培南、头孢吡肟、阿米卡星耐药率低。结论产AmpC酶和产ESBLs的大肠埃希菌和肺炎克雷伯菌为多重耐药菌株,治疗产2种β内酰胺酶细菌引起的感染亚胺培南为首选,头孢吡肟和阿米卡星可作为选用药物之一。

Detection of extended spectrum β lactamases and ApmC enzyme from Escherichia coli and Klebsiella pneumoniae

Objective: To study the drug-resistance of enzymes-producing Escherichia coli and Klebsiella pneumoniae, compare the resistance rate of enzymes-producing strains and non-enzymes-producing strains to 9 antitiotics for the basis of treating infection caused by enzymes-producing strains. Method: A cefoxitin three-dimensional test and E-test were used to detect AmpC enzyme and extended spectrum β lactamases (ESBLs) respectively. Simulaneously, drug-susceptibility were meastured by disk diffusion method in 110 strains of Escherichia coli and Klebsiella pneumoniae. Results: 6 (5.45%) strains are AmpC positive, 22 (18.2%) strains are ESBLs positive and 1(0.90%) strains AmpC+ESBLs was found among 110 strains of Escherichia coli and Klebsiella pneumoniae. The resistance rate of enzymes-producing strains were low to imipenem, cepepime and amikacin. Conclusion: Producing AmpC and ESBLs Escherichia coli and Klebsiella pneumoniae are multidrug-resistance strains. Imipenem is the most effective antibiotic for the treatment of infection caused by ESBLs or AmpC producing strains. Cepepime and amikacin are also effective for the treatment of such infections.