Isolation and Identification of Chicken Pathogenic E.coli in Henan

93 strains of chicken pathogenic E.coli were isolated from illed chickens with different pathological changes from 32 districts and cities in Henan Province.The test of pathogenicity,biochemistry and serotype identification were also conducted.The results of serotyping shows that among the serotypes were identified as mainly O78?O1 and O2,the mean isolation percentage are 35.14%?18.92%?13.51%,respectively.There also shows that there are no relativity between the pathogenicity and the serotyping.