Molecular Studies on Avian Pathogenic Escherichia Coli Infection In Broiler Chickens

This work aimed to carry out a molecular and phenotypic basedcharacterization of APEC isolated from different f0TI11S ofcolibacillosis in Egyptian poultry flocks and compare these isolateswith AFEC and environmental E. coli. Further analysis characterizedAPEC associated with colisepticemia cases the most prevalent form ofcolibacillosis. In addition the identification of the immunogenicepitopes that could be used as candidates for APEC vaccinedevelopment. Moreover this study utilized the molecular cloning as atool for the production of a candidate recombinant vaccine againstAPEC infection.Experiment 1: For characterization APEC isolated from differentforms of colibacillosis in Egyptian poultry flocks and compared theseisolates with AFEC and environmental E. coli. In addition furtheranalysis characterized APEC associated with colisepticemia cases. Inthis experiment, 219 E. coli isolates from 84 poultry flocks located infour provinces (Sharkia, Dakahlia, Gharbiyah and Ismailia) including153 APEC, 30 avian fecal E. coli (AFEC) and 36 environmental E.coli, were subjected to phylogenetic grouping and virulencegenotyping. Additionally, 50 of these isolates (30 APEC fromcolisepticemia and 20 AFEC) were subjected to a more extensivecharacterization, which included serogrouping, antimicrobialsusceptibility analysis, screening for seven intestinal E. coli virulencegenes (stxl, stx2, eae, espP, KatP, hlyA and fliCh7), multilocus.