Laboratory of Microbiology, School of Human Science and Environment, University of Hyogo, 1-1-12 Shinzaike-honcho, Himeji, Hyogo 670-0092, Japan.
Research Institute for Food and Nutritional Sciences, University of Hyogo, 1-1-12 Shinzaike-honcho, Himeji, Hyogo 670-0092, Japan.
J Vet Med Sci. 2021 Dec 9;83(12):1913-1917. doi: 10.1292/jvms.21-0387. Epub 2021 Nov 4.
To simplify the diagnosis of swine edema disease, overnight culture supernatants of swine clinical samples were assayed using immunochromatographic test strips we developed previously. Small-intestinal contents, mesenteric lymph nodes, and fecal samples were cultured in casamino acid-yeast extract broth overnight, after which supernatants were loaded onto immunochromatographic test strips to determine whether they could detect Shiga toxin 2e (Stx2e). Among 23 clinical samples in which PCR-identified stx2e-positive E. coli were isolated, samples from seven of ten small-intestinal contents, one of three mesenteric lymph nodes and six of ten fecal samples showed Stx2e-positive reactions in the protein-based immunochromatographic test. Additionally, one small-intestinal content sample, in which stx2e-positive E. coli were not isolated, showed an Stx2e-positive reaction. Furthermore, the immunochromatographic test results of the samples were associated with the toxin concentration determined by sandwich ELISA and cytotoxicity assay results on Vero cells. The toxin concentration range of the samples with positive and negative reactions were 2.1-196.2 ng/ml and 0-12.8 ng/ml, respectively. The sensitivity and specificity of this immunochromatographic test strip calculated from all clinical samples analyzed in this study were 60.9% and 94.4%, respectively. Our immunochromatographic test strip has strong potential for simple and accurate diagnosis for edema disease by detecting toxin expression, complementing the PCR method.
为简化猪水肿病的诊断，我们使用先前开发的免疫层析测试条对猪临床样本的过夜培养上清液进行了检测。将小肠内容物、肠系膜淋巴结和粪便样本在氨基酸-酵母提取物肉汤中过夜培养，然后将上清液加载到免疫层析测试条上，以确定它们是否能够检测到志贺毒素 2e (Stx2e)。在通过 PCR 鉴定为 stx2e 阳性大肠杆菌的 23 个临床样本中，从 10 份小肠内容物样本中的 7 份、3 份肠系膜淋巴结样本中的 1 份和 10 份粪便样本中的 6 份中检测到 Stx2e 阳性反应。此外，在未分离出 stx2e 阳性大肠杆菌的 1 份小肠内容物样本中，也显示出 Stx2e 阳性反应。此外，免疫层析测试的结果与夹心 ELISA 测定的毒素浓度和 Vero 细胞的细胞毒性试验结果相关。阳性和阴性反应样本的毒素浓度范围分别为 2.1-196.2 ng/ml 和 0-12.8 ng/ml。该免疫层析测试条对本研究中分析的所有临床样本的敏感性和特异性分别为 60.9%和 94.4%。我们的免疫层析测试条通过检测毒素表达，具有简单准确诊断水肿病的强大潜力，可补充 PCR 方法。
