ABSTRACT
Atypically developing chicken septicemia was studied at 3 farms in Bulgaria. In one of the observed centers of chicken septicemia infection no pathologic anatomical changes were evident while in the other two centers of infection serofibrinose and serofibrinose vitelline peritonitis, as well as pleurisy were present. In the bacteriological investigation carried out on 2969 samples 233 strains of chicken septicemia were isolated. Identification of 84 of them by the aid of the specific bacteriophage P. multocida 115 and of sugar and alcohol fermantation revealed that they can be classified as P. multocida. They are lyzated by a phage but do not reproduce it. Chicken septicemia cultures are virulent for white mice. In intramuscular injections of pullets these cultures prove not virulent, but their intravenous application kills the pullets in 5--10 days and the initial strain is isolated from all inner organs. The biological test on pullets is suitable for determining chicken septicemia culture virulence.
