产超广谱β-内酰胺酶大肠埃希菌和肺炎克雷伯菌的检测

Detecting extended-spectrum beta-lactamases in Escherichia coli and Klebsiella pneumoniae.

目的 选择适用于检测产超广谱 β 内酰胺酶 (ESBLs)临床大肠埃希菌、肺炎克雷伯耐药菌株的最佳方案。方法 临床分离的 110株大肠埃希菌和 84株肺炎克雷伯菌经初筛试验 ,用浓度梯度法 (Etest法 )、单纸片加抑制剂克拉维酸和单纸片加抑制剂舒巴坦扩散法、阿莫西林及氨苄西林双纸片协同试验 ,比较 5种方法的检出率及其差异。结果 Etest法对产ESBLs大肠埃希菌和肺炎克雷伯菌的检出存在明显的差异 (P <0 .0 1) ,肺炎克雷伯菌的检出率 (4 / 2 0 )明显低于大肠埃希菌 (16 / 2 6 ) ;单纸片扩散法加克拉维酸对两种菌的检出均较高 (16 / 2 6、12 / 2 0 )。检测产ESBLs大肠埃希菌时 ,除氨苄西林双纸片协同法 (8/ 2 6 )检出率低以外 ,其他 4种方法的检出率无明显差异 (P >0 .0 5 ) ,5种方法有较好的一致性。检测产ESBLs肺炎克雷伯菌时 ,单纸片扩散法加克拉维酸或舒巴坦 (12 / 2 0 )与Etest法、氨苄西林双纸片协同法的检出 (4 / 2 0 )存在差异 (P <0 .0 5 ) ,前两种方法检出率较高。

Objective To detect ESBLs in E.coli and K.pneumoniae with appropriate method.Methods The suspiciously produced ESBLs were detected by standard screen test among 110 E.coli and 84 K.pneumoniae. ESBLs possessing strains were confirmed by E test, single disc diffusion test with clavulanic acid or sulbatan, and two kinds of double disc synergy test. Results There was a significant difference between the detected rate of ESBLs in E.coli (16/26) and K. pneumoniae (4/20) by E test( P <0.01). The detected rate of K. pneumoniae was lower than that of E.coli. The single disc diffusion with clavulanic acid showed no difference in the detected rate of ESBLs E.coli (16/26) and K. pneumoniae (12/20). Except one kind of double disc synergy test (8/26), other methods showed no difference for the detected ESBLs in E.coli( P >0.05). The single disc diffusion test with clavulanic acid or sulbatan was applicable to confirm ESBLs in K. pneumoniae (12/20). Conclusions Single disc diffusion test is a sensitive, convenient and inexpensive method to confirm ESBLs in E.coli and K.pneumoniae in clinical laboratory.