28 (11.2%) isolates of pseudomonas aeruginosa were detected from 250 dead chicken embryos in addition 20(4.9%) isolates of the same organism were recovered from 406 examined dead chickens collected from differ ent sources at Assiut Governorate, also 23 & 30 isolates of ps.aeruginosa were isolated from internal organs of fish as well as human urine respect ively.
Pathogenicity tests in 7 day old chicken embryos by yolk sac inoculation as well as in 3 day old chicks by s/c route proved that the organism isolated from poultry, fish and human was highly pathogenic with high mortality rate, on the other hand the experimental infection in mice
and rabbit illustrated that human strain is the more pathogenic in mice and the poultry strain is the most pathogenic in rabbit. Reisolation of the organism in experimentally infected chicken embryos, baby chicks, mice and rabbits were conducted.