3种金黄色葡萄球菌肠毒素测定方法的评估

Evaluation of three methods for detecting Staphylococcus aureus enterotoxin

目的:建立荧光PCR系列检测金葡菌肠毒素基因,评价3种金葡菌肠毒素测定方法。方法:对185株金葡菌野生株同时采用荧光PCR法、微孔板法和酶联荧光免疫法等三种方法进行检测。结果:建立的荧光PCR系列体系其DNA灵敏度为1.34 ng/μl～2.80 ng/μl。以酶联荧光免疫法为金标准,185株金葡菌野生株中有124株产肠毒素,阳性率为67%;荧光PCR法的灵敏度为81%,特异度为87%;微孔板法(不分型)的灵敏度为87%,特异度为89%;微孔板法(分型)的灵敏度为83%,特异度为98%。结论:酶联荧光免疫法的检出率最高,适合用于样品初筛。所研制的荧光PCR体系操作简单、特异性高,适用于菌株的分型鉴定。

Objective：To establish a new system for detecting Staphylococcus aureus enterotoxins rapidly and sen- sitively, and to evaluate three methods in Staphylococcus aureus enterotoxin determination. Methods： Using the SYBR -Green real- time PCR, ELISA and ELFA to detect the endotoxins in 185 S. aureus strains. Results： For the real time PCR assay, the sensitivity achieved was 1.34 ng/μl ～ 2.80 ng/μl. With the ELFA as golden stand- ard, one hundred and twenty - four strains were positive. As to SYBR - Green real - time PCR, the sensitivity is 81%, and the specificity is 87%. As to ELISA（untype）, the sensitivity is 87%, the specificity is 89%. As to ELISA（type）, the sensitivity is 83%, the specificity is 98%. Conclusion： The ELFA has the highest detection rate, suitable for sample screening. The developed fluorescent PCR is easy to operate and has high specificity, it is suitable for typing and identification of strains.