SEROTYPING OF PASTEURELLA-MULTOCIDA ISOLANTS FROM POULTRY

P. multocida strains (607) were isolated in Israel from turkeys, geese and chickens. Serotyping was carried out by the gel-diffusion precipitin test. Antigens were heat-stable saline extracts of the organisms, and the diagnostic sera were produced in chickens using formalinized bacterins. Among 31 serotypes containing 1-5 antigenic factors, serotypes 1 and 3 accounted for 58.1, 80.8 and 88.9% isolants from turkeys, geese and chickens, respectively. Based on incidence of these serotypes in flocks examined, serotype 1 was predominant. Antigenic component variety was greatest for turkey strains, with some untypable. The record of isolants from various flocks indicated wide distribution of many of the strains. Strains with multiple antigenic factors and the possible implication of their presence in the preparation and use of vaccines were noted.