应用A蛋白酶联法快速检测柑桔溃疡病的研究

APPLICATION OF SPA-ELISA FOR RAPID DETECTION OF——Xanthomonas campestris pv.citri

应用A蛋白酶联法检测柑桔溃疡病表明,A蛋白预包被适宜浓度为2ug/ml,包被抗血清和检测抗血清工作浓度分别为10^(-5)和10^(-3),抗原稀释液和无症样品浸出液的灵敏率分别为1×10^(3-4)cfu/m和1∶90～100倍。此法对省内外26个溃疡病菌株均能检测,而不与阴性抗原发生反应。对171个柑桔无症样品检测表明,阳性率为63.20%,与常规检验结果基本符合。本法不需要纯化抗体及制备酶标抗体,检测周期仅12小时。

The applicability of SPA-ELISA for rapid detection of Xanthomonas campestrispv.citri was tested in this experiment.The appropriate precoating comcentration of proteinA was 2.0ug / ml,the dilutions for coating and detecting the antisera were 1:10~5and 1:10~3,respectively,and the concentration of HRP-SPA used was 1:40.The sensitivity of de-tecting specific antigen bacteria ranged from 1×10~3to 1×10~4c.f.u/ml and of detecting di-luted extracts of asymptomatic tissues of infected citrus ranged from 1:90 to 1:100.Allthe 26 isolates of X.campestris pv.citri from five province in southern China showed posi-tive reaction in the tests with SPA-ELISA but the negative control bactrial reactednegatively with the anti-GXO1 serum.Practical evaluation of 171 samples of citral materi-als indicated that 108,or 63.20% of the total,reacted positively with SPA-ELISA.Usingcrude antisera and commercial HRP-SPA,this procedure does not require the purificationof the antibody and the labelling of protein A conjugated with HRP.It takes only about 12hours to complete the detecting of a considerable number of samples.