Isolation And Identification Of Pneumonia Pathogen Of Mink, And Preparation And Test Of Multivalent Inactivated Vaccine Of Pseudomonas Aeruginosa

The bacterial pneumonia is an important disease in mink and confused us for many years. In order to investigate the main pathogenic bacteria and explore a safe and effective method, the study was carried out during the minks with pneumonia from Shandong province and Liaoning province from 2011 to 2013.Thirty-eight bacteria strains were isolated, including thirty-one strains of Pseudomonas aeruginosa, four strains of Klebsiella pneumoniae, one strain of Klebsiella ozaenae, one strain of Klebsiella oxytoca and one strain of Acinetobacter baumannii mixed infection with Pseudomonas aeruginosa were identified by biochemical methods and molecular biology techniques. The P. aeruginosa contains three serotypes:G (22/31),C (6/31), B (3/31) and G serotype was the most important. All the thirty-eight pathogenic bacteria isolated from mink with pneumonia shows a high pathogenicity in mice and all the strains are sensitive to Imipenem and Meropenem but resistant to ampicillin and amoxicillin/clavulanic acid according to the antibiotic sensitivity test.One strain of each G, B and C serotype of P. aeruginosa was as the standard antigen which was immune to the rabbit to collect the serum as the standard antibody. The optimum reaction concentration of the standard antigen and antibody was measured by the square formation agglutination test. Pseudomonas aeruginosa isolated strains were immune to mice to collect the serum. The mice serum titer was detected by the standard antigen. PA-L14(G serotype), PA-L05 (B serotype)and PA-L06 (C serotype) were finally confirmed to be the vaccine candidate strains.0.3% formaldehyde of final concentration was added to the bacterium suspension for inactivation treatment at 37℃ for 24h. The vaccine consists of 9 x 109 cfu/mL of G serotype,9 x 109 cfu/mL of B serotype,6 x 109 cfu/mL of C serotype,20% alumina gel and 0.01% Merthiolate. The vaccine was injected to the healthy minks without specific antibody for tracking the antibody titer. The result shows that the multivalent inactivated vaccine will stimulate the mink produce a high level of antibody titer, and it will last for three months. The vaccine will protect the mink from hemorrhagic pneumonia caused by Pseudomonas aeruginosa during the epidemic season. According to the return visit of a large-scale immune in farm minks, the vaccine shows a less adverse reaction and a good protection not only in vaccination but also in the emergency treatment after the illness.