Pathogenicity test were carried out on Mice, guinea pigs, pigeons and pigs with Fdwardsiella xda hoth culture suspension. The result indicatul that bc’th the original bacterial cell suspension and normal saline suspension were ethogenic to all experimenlly infai animals, The clinical sigis noted included fever, anorexia and even to death. Congestion and hemorrhages on ears, chin and ahiomen were also oIerved in infected pigs, The autoptic findings included swelling and peripheral hemorrhages of lymph ncdes on various region, hemorrhage and n&rosis of some visceral organs. On the other hand, the histopathology finding revealed typical hemorrhagic and necrotic change. The thogens were recovered from various visceral organs and parts of blocd specimen of pigs inoculaI.
Two different concentrations of inactivated trial bacterin w puepared. The potency assay was carried out in mice by intraperitioneal immunizinon. The potency level of the single dose was the same to that of bx’st infrtion after challenge of the two different concentrations of lractrins. The result indicated that the protection potency in 10 nines if the kacterin contains 3-4xl ($9 of organisms per mililiter. This experiment strongly suggesti that the Mouse mcdel” could ke applied for potency assay on E3.wardisiella thda bcain.