Development And Preliminary Application Of A Rapid Test Strip For Domestic Animal's Schistosomasis Japonicum

Schistosomiasis caused by schistosome japonicum is an important zoonosis in China and southeast About 40 mammalian species have been found naturally infected with S. japonicum and bovines, pigs and sheep are important reservoir hosts. At present, parasitological and immunological tests such as ELISA, dot-ELISA and IHA, are the most commonly used methods in domestic animal's Schistosomasis Japonicum diagnosis. All these methods were unsatisfactory for the direct use in the field. The parasitological examination methods such as egg hatching test, are of high specificity but of low sensitivity in area with light and moderate infections. The most commonly used immunological techniques are quite sensitive and specific, and have been proved very useful in confirming the diagnosis and in seroepidemiological studies. However, these methods are all time-consuming and require a laboratory equipped with special instruments and trained personnel. Here we reported the development and preliminary application of a rapid test strip for diagnosis of domestic animal's Schistosomasis Japonicum.Preparation and selection of the diagnosis antigen: Soluble Egg Antigen (SEA) was extracted from eggs of S. japonicum from artificially infected rabbit and then divided into two sections SEA1 and SEA2 by Sephdax G-200 . The recombinant antigen LHD-Sj23/pGEX was prepared by expression of LHD-Sj23 in BL21 (DE3) as a fusion protein with 26 KD GST and purification with Glutathione-Sepharose TM .The indirect ELISA was used to compare the diagnosis sensitivity and specificity of these three antigens: SEA, SEA1 and LHD-Sj23/pGEX. The results showed that SEA as the diagnosis antigen for schistosomiasis will be better than the other two antigens.Preparation of the diagnosis strip: Two rabbits ware immunized 3 times with SEA and the anti-SEA antibody IgG was salted out by ammonium sulfate. 40nm gold colloidal was produced by Using sodium citrate reduced aurum chloride. After identification by using UV spectrophotometer scanning, the gold colloidal was...