胶体金免疫层析法检测鼠疫F1抗原的研究

目的 研究胶体金免疫层析试纸条检测鼠疫F1抗原的敏感性和特异性.方法通过鼠疫F1抗原单克隆抗体(F1MAb)捕捉F1抗原的胶体金免疫层析(GICA)试纸条,检测308只强毒鼠疫耶尔森菌(鼠疫菌)感染鼠脏器标本和225份对照鼠(达乌尔黄鼠217只,小白鼠5只,豚鼠3只)标本,同时用鼠疫反向间接血球凝集试验(RIHA)微量法和细菌培养做平行检测.结果 225只对照鼠鼠疫细菌学检验及GICA和RIHA的F1抗原检测均为阴性,GICA和RIHA在1×108 cfu/ml水平上未发现与近缘假结核耶尔森菌有交叉反应.GICA、RIHA对鼠疫菌检测灵敏性为2.5×105、2.0×105cfu/ml;检测F1抗原灵敏性为1、10 μg/L.GICA与细菌学检验符合率为97.94%(522/533),Kappa值=0.959,阳性检出率组间比较,差异无统计学意义(x2=0.36,P＞0.05);与RIHA符合率为97.94%(522/533),Kappa值=0.959,阳性检出率组间比较差异有统计学意义(x2=9.09,P＜0.05).308只实验鼠样本细菌培养阳性284只,284份细菌培养阳性标本中,GICA有280份检测阳性,阳性率为98.59%,高于RIHA[阳性率为96.13%(522/533)],两组比较差异有统计学意义(x2=5.14;P＜0.05).GICA的敏感度为98.59%(280/284),特异度为97.19%(242/249),阳性预测值为97.56%(280/287),阴性预测值为98.37%(242/246),Youden指数为0.9578.结论 GICA检测鼠疫F1抗原敏感特异,快速简便,是鼠疫早期快速诊断中有应用价值的检测技术.

Gold-immunochromatography assay for detection of Yersinia pestis F1 antigen

Objective To study the sensitivity and specificity of gold-immunochromatography assay (GICA) for detection of Yersiniapestis(Y. pestis ) F1 antigen. Methods Viscera organ(liver and spleen) specimens of 308 mice with virulent Y. pestis infection and 225 control specimens of rats(217 Spermophilus dauricus, 5 mice,3 guinea pigs) were detected by GICA dipstick with monoclonal antibody against plague F1 antigen (F1MAb).Meanwhile, micro-method of reverse indirect hemagglutination assay(RIHA) and bacteria culture were carried out for parallel testing. Results Bacteriological examination of 225 control specimens, and F1 antigen detected with GICA and RIHA were all negative. No cross-reaction with related Yersinia pseudotuberculosis at 1 x 108 cfu/ml level was found in GICA and RIHA. Detection sensitivity of Y. pestis by GICA and RIHA were 2.5 × 105 cfu/ml and 2.0 × 105 cfu/ml, respectively, and of F1 antigen were 1μg/L and 10 μg/L, respectively. Coincidence was 97.94% (522/533) between GICA and bacteriological test, Kappa = 0.959, and the difference was statistically insignificant(x2 = 0.36, P ＞ 0.05); and 97.94%(522/533) between GICA and RIHA, Kappa = 0.959, with statistically significant difference in the positive detection rates(x2 = 9.09, P ＜ 0.05). Out of the 308 infected mice, 284 were positive of plague bacterial cultured, In 284 samples with positive bacterial culture, there were 280 of positive detected by GICA for F1 antigen, positive rate of F1 antigen was 98.59%, higher than that by RIHA[the positive rate of 96.13%(522/533)], with statistically significant difference(x2 = 5.14, P ＜ 0.05). Sensitivity of GICA was 98.59% (280/284), specificity was 97.19% (242/249), positive predictive value (PPV) was 97.56% (280/287),negative predictive value ( NPV ) was 98.37% (242/246), and Youden index was 0.9578. Conclusions GICA is sensitive and specific, fast and simple in detection of F1 antigen of the plague. It's a valuable detection technique for early and rapid diagnosis of plague.