三维法测定耐头孢美唑菌β-内酰胺酶的研究

目的检测耐头孢美唑的肠杆菌科细菌持续高产AmpC酶和超广谱β-内酰胺酶(ESBLs)及对其他抗生素的耐药状况。方法采用三维法测定AmpC和ESBLs及纸片扩散法测定16种抗菌药物的抑菌环直径。结果50株耐头孢美唑的肠杆菌科菌有24．0％的菌株同时产AmpC酶和ESBLs，有28．0％的菌株单产AmpC酶，有6．0％的菌株单产ESBLs，有46、0％的菌株AmpC酶和ESBLs酶均阴性；AmpC和ESBLs总的阳性率分别为48．0％和26．0％；AmpC和ESBLs总的阳性率分别为44．0％和26．0％；肠杆菌属的产AmpC酶率最高，不动杆菌属、铜绿假单胞菌、弗氏柠檬酸杆菌、气单胞菌属均能产生AmpC酶，而大肠埃希菌产AmpC酶的几率较小。结论耐头孢美唑的肠杆菌科细菌产AmpC酶几率较高，应加强监测。

Determination of ESBLs produced by cefmetazole-resistant bacteria by three-dimensional detection

Objective To determine the AmpC enzyme and ESBLs continuously produced by cefmetazole-resistant Enterobacteriaceae and its resistance to other antibiotics.Methods The three-dimensional detection and paper strip method were used to determine the inhibi- tion zone of 16 antibiotics for the cefmetazole-resistant Enterobacteriaceae.Results Simultaneous production of AmpC enzyme and ESBLs were found in 24.0%,simple production of AmpC enzyme in 28.0%,simple production of ESBLs in 6.0% and no production of both in 46.0% of the 50 strains of cefmetazole-resistant Enterobacteriaceae.The total positive rate was 44.0% and 26.0% for AmpC and ESBLs, respectively.Most of the AmpC enzyme was produced by Enterobacter.Meanwhile,Acinetobacter,Pseudomonas Aeruginosa,Citrobacter freundii and Aeromonas could produce the enzyme.However,the enzyme was rarely produced by E.coli.Conclusions The cefmetazole- resistant Enterobacteriaceae should be closely monitored because it is more likely to produce AmpC enzyme.