RESUMEN
Colibacillosis is one of the most prevalent diseases in the world that causes multimillion-dollar annual losses. In order to evaluate molecular epidemiology of some virulence associated factors in Escherichia coli, isolated from poultry, the presence of iut A, iss, hlyF, omp T, iro N, afa, sfa [S] and pap G [II] were investigated by multiplex PCR assay. Two hundred thirty four Escherichia coli isolated from avian colibacillosis [APEC] and fifty four fecal E. coli isolates from the feces of apparently healthy birds [AFEC] were investigated for presence of some virulence associated genes by two panel of multiplex PCR. Statistical analysis was performed using x[2] test, the p-value was