Identification of Brucella melitensis and Molecular Cloning of Its BP26 Gene into p ET24a(+) Vector

摘要

Brucella spp. are pathogenic to humans and domestic animal. Nowadays,there is no effective vaccine and control strategy in China. So,it is necessary to research effective vaccines for prevention and treatment of this disease. In order to deal with these,we isolated and identified the type of Brucella in Darhan Muminggan Joint Banner and Siziwang Banner of Inner Mongolia. Totally 26 samples of sheep blood which were positive in serological test,one sample of spleen from aborted and one sample of secretion from birth canal were isolated,and the 16 S r DNA genes of positive samples were sequenced. Phylogenetic analysis proved that there were four isolates similar to B. melitensis. As an important diagnostic antigens of B. melitensis,the BP26 gene was amplified. The BP26 gene was cloned into vector p ET24a( +) and conducted sequence analysis. The BP26 gene was 900 bp,with an open reading frame of 753 bp. The homology of BP26 gene with the vaccine strain M5 was 100%,and that with S2 and A19 vaccine strains was 99. 99%. These finding supported the development of BP26-based specific serodiagnostic test and vaccine for B. melitensis in China.