Abstract
A total of 100 migratory birds were collected from Dakahlia and Damietta Governorates. All samples were subjected to clinical and postmortem (P.M) examination followed by bacteriological examination for detection of Avian Pathogenic E. coli infection. Out of 100 samples, 25 samples were distinguished as positive for Escherichia coli. Accurately, 4 E. coli serogroupes were identified in 25 positive samples and the most predominant serogroup were O125 (76 %), O126 (8%), O158 (8%), O86 (4%) and untypable E. coli (4 %). Studying antibiotic resistance pattern of E. coli isolates revealed that 64% of the isolates demonstrated multidrug resistance pattern. The highest resistance rates were recorded against Ciprofloxacin (88%) followed by Gentamycin (80%), Streptomycin (68%), Norfloxacin (40%), Colistin (16%) and Doxycycline (4%). Conventional PCR was done for detection of virulence genes (fimH, tsh, eaeA, stx1and stx2) in 10 isolates and the results revealed that; 100%, 60%, 40%, 0% and 0% were positive for these virulence genes, respectively. By studying the effect of one isolate of O125 No. 78 in commercial chicken (cobb) and ducks (pekin) we found that, more sever signs, pathological lesion and 100% mortality rate in cobb chicken than pekin ducks which had less signs nor pathological lesion with 10% mortality rate only.

Key words: Avian Pathogenic E. coli, Resistant to antibiotic, Virulent Genes, Migratory Birds, Pathogenic, Conventional PCR