| Riemerella anatipestifer is the etiologic agent of exudative septicemia, a contagious, chronic or acute septicemic disease of ducks, geese, turkeys and pheasants. R. anatipestifer has caused severe losses in duck production. R. anatipestifer was first described in geese by Riemer in 1904, and has been reported in America, UK and Canada et al subsequently. Guo YP, in China, first reported R. anatipestifer infection from 3 commercial duck farms in Beijing in 1982. Lin YJ reported the first isolation of Fujian province from Fuzhou in 1989. R. anatipestifer has a worldwide distribution. R. anatipestifer is a gram-negative rod-shaped bacterium, belonging to the family Flavobacteriaceae. Presently, 21 serotypes have been identified. There is no obvious cross-protection among serotypes.Veterinary drug has ever been the major measure to control R. anatipestifer infection. But it must face the problems such as low effectiveness, high cost and drug residue in carcass. So immunization would be the main trend for controlling R. anatipestifer infection.Serotype investigation of R. anatipestifer has been made in our study. 163 strains were isolated from Fujian province, and they belonged to 1(22.7%), 2(57.1%), 13(1.2%) and unidentified (19%). The result demonstrated the main serotypes of R. anatipestifer in Fujian province were serotype 1 and 2. The selection test of 3 adjuvant indicated that the protection rate and unwant effect of the oil-emulsion bacterin of R. anatipestifer were the highest, that of the propolis bacterin secondary, while that of the aluminium hydroxide bacterin the lowest. Ducks have lower unwant effect vaccinated with the same vaccine by route into the neck skin than by muscle of thigh. Considering the effect of application and unwant effect, we selected the oil-emulsion bacterin of R. anatipestifer and the inject location of subcutaneous neck skin. The test of non-bacteria and security showed the oil-emulsion bacterin of RA serotype 1 was up to grade, the protection rate is between 83.3% to 100% shortly after immunization, and this figure still keep on 100% in 56 days of postimmunization. The Enzyme-linked Immunosorbent assay(ELISA) to detect R. anatipestifer antibody in serum of ducks has been developed in this study. The bivalent bacterin of R. anatipestifer serotype land 2 was developed on the ground of upper research. And the vaccine has been applied to 1 million ducks in Fujian province.
|
PDF Full Text Request