Abstract: 　AIM: To study the association expression of two genes encoding GST of Schistosoma japonicum and K99 of enterotoxigenic Escherichia coli. METHODS: PCR technique was used to gain the K99 gene. After digestion with BamHⅠ and EcoRⅠ, the gene was cloned into the plasmid vector pUC18 by using recombinant DNA techniques. The other target gene of GST in pSj5 plasmid was obtained by EcoRⅠ digestion, and was then ligated into the recombinant plasmid pUC18 K99. The expressed product was assayed by SDS PAGE, Western blotting, reversal IHA, ELISA and transmission electron microscopy. RESULTS: Co expression product of around 50 kDa was obtained. The protein was recognized by anti GST and anti K99 antibodies (ELISA and IHA), and acted as pilus on the surface of transformed DH5α E.coli bacteria. CONCLUSION: Co expression of the genes encoding GST and K99 was successfully achieved.

Key words: Schistosoma japonicum, GST, K99 pili antigens, gene expression