Preparation method for Brucella shell vaccine strain

A preparation method for Brucella shell vaccine strain is disclosed, relates to the field of molecular biology and microbiology, and helps to solve the problem that conventional bacteria shell preparation method is high in cost and not suitable for large-scale production. The method comprises: respectively cloning PCR products of homogenous arms at the upstream and at the downstream of a specific gene of Brucella strain genome to a pMD18-T Simple vector to construct recombinant plasmids, performing double digestion on the recombinant plasmids, successively connecting with plasmid pBK-CMV-SacB subjected to digestion processing for constructing a suicide plasmid, performing PCR amplification on a temperature-control lysis part of a temperature-control expression plasmid pBV220-E, performing digestion processing on the amplification product, inserting into the suicide plasmid; and transforming the temperature-control lysis type suicide plasmid into competent Brucella, and performing positive and negative screeni