Immunization of mice and chinchillas against Pseudomonas aeruginosa.

The possibility of production of an effective vaccine against Pseudomonas aeruginosa infections in fur-bearing animals was investigated. Twenty-three strains of Pseudomonas aeruginosa isolated from diseased chinchillas and mink were tested in mice for their immunogenic properties. Nineteen of these strains produced good immunity against homologous strains, and three of these produced also good immunity against heterologous strains. Of the remaining four strains two produced moderate immunity and two no immunity. It was found that 0.05% or 0.5% formalin added to suspensions of Pseudomonas aeruginosa or ultrasonification of the suspension produced better results than 0.5% phenol, 0.3% alcohol or heat at 100 degrees C for half an hour. Chinchillas vaccinated with two doses of formolized Pseudomonas aeruginosa bacterins were immune for 36 weeks after the second dose, while all controls died within 48 hours after being challenged. It was found that the protection afforded by the polyvalent bacterin extended beyond the strains included in the vaccine.A field survey on 34 ranches which included over 7,700 chinchillas showed very promising and encouraging results.