Isolation of Vero toxin Producing Escherichia coli from Chickens with Swollen Head Syndeome

strains of O78 E.coli(from Harbin)and 1 stain of O8 E.coli(from Anshan)were isolated from chickens with Swollen Head Syndrome(SHS)by bacterial culture,and then confirmed by morphological observation,biochemical and serological tests.All 4 strains produce the cytotoxin to Vero cells similaras E.coli.Verotoxin.Hisfopathology observation revealed fibrinopurulent inflammation,edematization and E.coli granulomas in air space of cranial bones and facial skin.Heterophills infiltratiow and bacteria granular structures were also obsersed in other organs,including henrt,liver,kindey,etc.