基于重组优势多表位抗原的梅毒间接酶联免疫吸附试验与梅毒螺旋体血凝试验和甲苯胺红不加热血清试验检测梅毒螺旋体抗体的比较研究

目的 建立操作简便、特异性好、敏感性高的血清梅毒抗体的间接酶联免疫吸附试验(ELISA)。方法 通过计算机分析选择梅毒螺旋体优势抗原表位,构建了梅毒螺旋体多表位优势嵌合抗原(rTpN15-TpN17-TpN42-TpN47)表达载体,转化宿主菌HB101进行表达,纯化获得高纯度融合抗原。在此基础上,以纯化抗原包被酶联板,建立检测血清中梅毒抗体的间接ELISA法。利用该方法与梅毒螺旋体血凝试验(TPHA)和甲苯胺红不加热血清试验(TRUST)同时检测了126例梅毒可疑血清样本,对检测结果进行了比较研究。结果 梅毒螺旋体多表位优势嵌合抗原(rTpN15-TpN17-TpN42-TpN47)在大肠杆菌中获得了高效表达,并成功建立了检测血清中梅毒抗体的间接ELISA法及试剂。对126例梅毒可疑血清样本的检测结果,ELISA、TRUST、TPHA的检出阳性率分别为75.40％(95/126)、72.22％(91/126)、70.63％(89/126),其中TRUST有29例,TPHA有6例为可疑阳性。TPHA检测的6例可疑阳性中,有5例ELISA、TRUST均为阳性;而TRUST测出的29例可疑样品中,仅7例ELISA、TPHA阳性。结论 多表位嵌合抗原ELISA试剂在特异性、敏感性与TPHA法相近,但明显优于TRUST法。

Establishment of ELISA based on Recombinant Multi - epitope Chimeric Antigen and Its Comparison with TPHA and TRUST for Determining Antibodies against Treponema pallidum

Objective To establish simple indirect enzyme linked immunosorbent assay(ELISA)with high sensitivity and speci-ficity for detecting syphilis antibodies in serum. Methods The dominant epitopes of Treponema pallidum were analyzed and picked out by using computer software Goldkey.Then, recombinant multi ~ epitope chimeric antigen(rTpN15-TpN17-TpN42-TpN47)expression vec-tor of Treponema pallidum was constructed, and transformed into E . coli HB101. Based on this recombinant fusion antigens, one kind of in direct enzyme-linked immunosorbent assay(ELISA)was established.Then, 126 suspected serum samples of syphilis antibodies were tested by this method, and its results were compared with the same samples detected by TPHA and TRUST. Results Recombinant multi epitope chimeric antigen of Treponema pallidum was highly expressed in E.coli and purified consequently, and an indirect enzyme - linked immunosorbent assay(ELISA) was established successfully. The results showed that the positive rates detected by ELISA, THPA and TRUST were 75.40% (95/126), 72.22% (91/126) and 70.63% (89/126)respectively and suspected sera were 29 by TRUST and 6 by TPHA, respectively. As to the 6 suspected sera by TPHA, 5(5/6) tested by ELISA and TPHA were positive. However, among 29 suspected sera by TRUST, only 7(7/29)were positive according to ELISA and TPHA. Conclusion According to the sensitivity and specificity, ELISA is in the same level as TPHA, but is obviously superior to TRUST.