[Construction and identification of recombinant adenovirus of muramidase-released protein gene fragment from Streptococcus suis type 2].

Objective: To construct and identify the recombinant adenovirus of muramidase-released protein (MRP) gene fragment from Streptococcus suis type 2 (SS2).

Methods: The specific primers were designed based on the sequence of MRP gene fragment. The MRP gene fragment (467-1351 bp) was amplified by PCR method with genomic DNA of SS2 as a template. PCR products were cloned in pMD18-T vector. Then MRP gene fragment was linked into the adenovirus shuttle plasmid (pShuttle-CMV) to construct recombinant shuttle plasmid (pShuttle-CMV-MRP). After PmeI digestion, it was transformed into BJ5183-AD-1 competent cells containing adenoviral backbone plasmid pAdEasy-1 to construct homogeneous recombinant adenovirus plasmid (pAdeno-CMV-MRP). Then the recombinant adenovirus plasmid was linearized by PmeI and then transfected into AD-293 cells for viral packaging. Finally, the virus liquid was tested by PCR and Western blotting.

Results: Cytopathic effect (CPE) was observed at 8 d after transfection of linear pAdeno-CMV-MRP in AD-293 cells. MRP gene fragment and protein expression were also detected in the virus liquid.

Conclusion: The recombinant adenovirus of MRP gene fragment (rAdeno-MRP) from SS2 was constructed successfully.