Construction Of Labelling Vaccines Of Brucella And The Establishment Of Differential Diagnosis

Brucellasis is a zoonotic disease caused by a small intracellulat gram-negative bacterium which is pathogenic for humans and many animals. Cattle,sheep and swine can infection easily and this infection induces abortions.Touch infectious animals and its products can cause the disease.Brucellosis distribute all over the world and is one of a biological warfare agent called by western countries.It has six species and twenty biotypes, B.meli.melitensis,B.meli.abortus and B.meli.suis are mainly in our country.Resently,different species of brucella was isolated from sea animals ,and may be there are other species which don't infect human.Control of the spread of the disease in domesticated animals is the use of vaccines for whole-herd vaccination programs,except kill all the infectious animals.But because the poor protection,serological and production cost of the traditional vaccine, we do reseach for genetic recombinant subunit vaccine.P39 protein is the best kown T-cell antigen,it exists all of Brucella except three species.it also induced a positive delaydetype hypersensitivity(DTH) reaction and stimulated the production of interferon(IFN-γ) in infected animals.Purified recombinant P39 seemed to be a promising antigen for the serologic diagnosis of animal brucellosis.Thus,P39 appeared to be useful for the detection of both humoral and cellular immune responses of infected animals.Amplified the certain gene which containing p39 gene from the whole genome of B.melitensis by PCR,and inserted into pBluesciptSK(+) vector,then replace the p39 gene with Kan,recombinant plasmid was completed.The plasmid can't replicate in Brucella. Homologous recombination can occur when transform the plasmid to Brucella,then we obtain the labeling vaccine of Brucella. We diagnosis the infected animals and isolate the antibody of the blood serum, detect by P39 protein, natural infection will identified when there are positive action.In summary , we constructed the P39 protein deleted vaccine successfully by homologous recombination. It can discriminate the native immunity from vaccinal immunity. The reseach will promote the clinical investigations of Brucellosis in the nation.