Isolation And Identification Of Avian Pathogenic Escherichia Coli And Studies On Polyvalent Oil-emulsion Inactivated Vaccine

Avian Pathogenic Escherichia coli from Jinzhou area were isolated and identified in this research, and polyvalent oil-emulsion of Escherichia coli had been made and field trial of the vaccine had been done. Experiment including:some samples were collected from chicken which had been diagnosed with E.coli in Jinzhou typical area.The dominant serotypes of E.coli were confirmed and selected as vaccine candidates by bacterial isolation and culture, biochemical experiment, pathogenic analysis and serology test. As a mater seed,the dominant serotype strains were incubated and proliferated, the polyvalent oil-emulsion inactivated endemic vaccine was made.The vaccine was passed several tests, Such as security, validity, immunity duration, conservation time, minimum does and field test.As a result, 55 strains were isolated, in which there were 41 strains infectious pathogen. 11 confirmed serotypes were O₇8, O₁, O₂6, O₂, O₉, O₁8, O₁1, O₇, O₇3, O₂0 and O₃6. In Jinzhou, prevalent serotypes were O₇8, O₁, O₂6 and O₂. Multivalent inactived vaccine made from prevalent serotypes strains possessed good safety and high stability. Immunity duration is over 6 months. The vaccine can conserve for 12 months at 4℃,6 months at 25℃. Minimum dose is 0.25mL per chickling, 0.5mL per adult chicken. From the result of the field studies, it can be concluded that a vaccination of chicken is safe and potent and can effectively prevent Chicken Colibacillosis. It can be widely used in Jinzhou.