Establishment and evaluation of an iELISA using the recombinant membrane protein LHD-Sj23 for the serodiagnosis of Schistosoma japonicum infection in cattle in China.

Schistosomiasis is an important zoonosis and some livestock especially cattle play a crucial role in disease transmission in endemic areas. In order to establish an effective diagnostic method for detecting Schistosoma japonicum infection in cattle, the gene encoding large hydrophilic domain of Sj23 (LHD-Sj23) was cloned and expressed in Escherichia coli as a fusion protein with GST tag. The purified rLHD-Sj23-GST was used as an antigen in an indirect enzyme-linked immunosorbent assay (iELISA). The sera samples collected from cattle experimentally infected with S. japonicum from week 0 to week 54 post-infection were examined by rLHD-Sj23-GST iELISA. Furthermore, 484 clinical sera samples collected from cattle in schistosomiasis epidemic and free areas in China were tested by this method with a positive rate of 18.4% and 3.44%, respectively. The findings from this study indicated the established iELISA is a useful method for diagnosing S. japonicum infection in cattle and could be used in serological surveys to map out the prevalence of this disease.