Virulence of Avian Serotype A1 Pasteurella multocida for Chickens and Mice

The virulence of Pasteurella multocida (P.multocida) serotype A1 for chickens and mice was determined. Groups of chickens and mice were exposed intramuscularly and intraperitoneally to various concentration of P.multocida broth culture, respectively. This strain was highly virulent for chickens so that those exposed to only 7c.f.u. of the organism died in less than 24 hours. Groups of mice exposed to the virulent strain died during 48 hours post inoculation. Microbiological examination resulted in the isolation of P.multocida from exposed chickens and mice. No isolation was made from unexposed control groups. The result indicates that the isolate is highly virulent for both chickens and mice.