细菌金属β-内酰胺酶检测方法的评价

Evaluation to the Methods of Detecting Bacterium Metallo-beta-lactamase

目的比较用EDTA.Na2和2-巯基乙醇为酶抑制剂的协同过筛法来检测细菌金属酶的敏感性,为临床筛选金属酶,探究细菌的耐药机制提供依据。方法以EDTA.Na2和2-巯基乙醇为酶抑制剂,头孢他啶(CAZ)头孢噻肟(CTX)和亚胺培南(IPM)为底物在M-H平板上用纸片扩散法进行抗生素协同敏感性检测。结果对28株对IPM或三代头孢耐药的已知产金属酶的菌株进行以上两种方法的检测,应用2-巯基乙醇筛选法检出的金属酶阳性率78.6%(22/28);应用EDTA筛选法检出金属酶阳性率57.1%(16/28);两种方法共同使用检出阳性率92.9%(26/28)。结论两种方法无显著性差异(χ2=1.75<χ02.05(1)=3.84,P>0.05),且两种酶抑制剂共同应用对金属酶的检出率更高。

Objective To compare the sensitivity of two methods, in which EDTA and 2-mercaptoethanol were used as enzyme inhibitors for detecting metallo-beta-lactamase, and to screen metallo-beta-lactamase so as to study the drug resistant mechanism. Methods The enzyme inhibitors were EDTA and 2-mercaptoethanol and the substrates were ceftazidime, eefotaxime and imipenem. The microbiological sensitivity synergic tests were processed by K-B method in the MH agar. Results Among the 28 strains of metallo-beta-lactamase producing bacteria, the positive srains accounted for 57.1% （16/28） by EDTA method, 78.6% （22/28） by 2-mercaptoethanol method, and 92.9% （26/28） synchronously by the two methods. Conclusion It is concluded that there is no significant difference between these two methods, and that these two enzyme inhibitors are used at the same time can increase the positive rate of metallo - beta - lactamase detection.