ChromID ESBL选择性显色平板对产ESBLs肠杆菌科细菌筛选效果的评价

目的 评价ChromID ESBL选择性显色平板对产超广谱β-内酰胺酶（ESBLs）肠杆菌科细菌的筛选效果。方法 选取临床分离的371株肠杆菌科细菌进行ESBLs的检测，用ChromID ESBL选择性显色平板做筛选试验，同时用纸片确证法做确证试验，采用Kappa检验对两者结果进行一致性分析。结果 两种方法对371株肠杆菌科细菌ESBLs检测的总Kappa值为0.761。ChromID ESBL选择性显色平板法的总灵敏度为95.2%，总特异度为83.5%。对大肠埃希菌、肺炎克雷伯菌、奇异变形杆菌分别统计，其Kappa值分别为0.832、0.514、0.778；ChromID ESBL选择性显色平板法对其检测灵敏度分别为95.7%、91.3%、100.0%，特异度分别87.6%、72.9%、90.9%。另外有6株大肠埃希菌在该显色平板上显非特征色。结论 ChromID ESBL选择性显色平板对产ESBLs肠杆菌科细菌的筛选效果与纸片确证法总体一致性较好，其灵敏度和特异度较高，可应用于临床。但该显色平板对产ESBLs肺炎克雷伯菌的筛选效果与纸片确证法一致性一般，其特异度也较低；对大肠埃希菌存在一定的假阴性，对于该显色平板上生长的绿色和白色菌落需要做进一步鉴定确认。

Effect of selective chromogenic agar medium ChromID ESBL for detection of Enterobacteriaceae producing extended-spectrum beta-lactamases

Abstract: Objective To evaluate the effect of a selective chromogenic agar medium, ChromID ESBL, for the detection of Enterobacteriaceae producing extended-spectrum beta-lactamases (ESBLs). Methods 371 clinical isolates of Enterobacteriaceae were tested by using selective chromogenic agar medium ChromID ESBL and double disc diffusion method. The results were analyzed statistically. Results The overall Kappa value showing the consistency between the two methods was 0.761. The overall sensitivity and specificity of ChromID ESBL were 95.2% and 83.5% respectively. For E.coli, Klebsiella pneumoniae and Proteus mirabilis, the Kappa values were 0.832, 0.514 and 0.778 respectively, the sensitivities were 95.7%, 91.3% and 100.0% respectively, and the specificities were 87.6%, 72.9% and 90.9% respectively. And there were 6 strains of E. coli which showed non-characterized colors in the chromogenic agar medium. Conclusion The effect of selective chromogenic agar medium ChromID ESBL was good for detection of ESBLs-producing Enterobacteriaceae with high sensitivity and specificity, but not satisfactory for ESBLs-producing Klebsiella pneumonia. There were some false negative results for detection of E.coli. The green and white strains grew on the medium need further identification with another method.