stx-PCR方法、Vero细胞毒性试验和酶联免疫试剂盒3种方法检测产志贺毒素大肠埃希菌的评估

Comparative evaluation of stx-PCR,Vero cell assay and Verotoxin enzyme imminoassay for detection of Shiga toxin-producing Escherichia coli

目的评价stx-PCR方法、Vero细胞毒性试验和酶联免疫试剂盒3种方法在检测产志贺毒素大肠埃希菌的特异性和敏感性的差异。方法运用stx-PCR方法、Vero细胞毒性试验和酶联免疫试剂盒分别对29株大肠埃希菌参考菌株和45株食品分离大肠埃希菌株进行检测。结果 stx-PCR方法可以判定50株菌携带stx基因,同时Vero细胞毒性试验可以判定这些菌株具有细胞毒性,两者的一致性为100%;酶联免疫试剂盒能判定其中38株菌具有志贺毒素。结论 3种方法都具有很好的特异性。stx-PCR方法和Vero细胞毒性试验较酶联免疫试剂盒具有更高的敏感性,试剂盒适用于食源性疾病暴发事件中产志贺毒素大肠埃希菌的快速筛选,stxPCR方法推荐作为实验室常规快速检测方法,Vero细胞毒性试验是检测产志贺毒素大肠埃希菌是否具有志贺毒素生物学活性的金标准方法。

Objective To evaluate the suitability of stx-PCR, Vero cell assay and commercial enzyme immunoassay for detection of Shiga toxin Escherichia coli and to compare relative sensitivity and specificity of three different methods for detection of Shiga toxin-producing Escherichia coli. Methods Using stx-PCR, Vero cell assay and commercial enzyme immunoassay to detect 35 Escherichia coli reference strains and 45 strains isolated from food. Results The three methods all had good specificity. 31 strains gave positive reaction in the Vero cell assay and in the stx-PCR. The consistency between the Vero cell assay and stx-PCR was 100%. Only 38 strains can be detected by commercial enzyme immunoassay. Conclusion stx-PCR method can serve as a routine rapid detection method in the laboratory. Vero cell assay is recommended to be the gold standard to determine whether the bacteria had the functionally active toxin. Commercial kit was suitable for preliminary rapid detection during clinical testing and outbreaks offood-borne diseases.