A total of 205 chicken samples from apparently healthy broiler chickens (35 and 30), diseased broiler
chickens (35 and 30) and freshly dead ones (35 and 40) were collected in winter (from December to
February) and summer (from June to August) seasons, respectively from Menofyiea government. The
results showed that the incidence of E.coli in apparently healthy broiler chickens was 15.7%, diseased
broiler chickens 37.1% and in freshly dead ones 55% in winter season while in summer season was
15.8% in apparently healthy, 17.5% in diseased broiler chickens and 18.7% in freshly dead one. The
serogroups of E.coli that obtained by serological identification were O₁₂₈, O₇₈, O₁₁₁, O₁₂₄, O₅₅, O₁₄₂, O₁₁₄,O₂ and O₁. The results of antibiotic sensitivity test for isolated E.coli showed that the isolated E.coli
were highly sensitive for norfloxacin (60%), gentamycin(50%) , neomycin (50%) , streptomycin(50%)
and chloramphenicol (50%). moderately sensitive for doxcyclin (10%) and erythromycin(40%) and
highly resistant for amoxacillin /clavulinic acid (0%). The results of multiplex PCR showed that eae A(
intimin or E.coli attaching and effacing) gene detected in O₁₂₈,O₅₅, O₁and O₂, OmpA (outer membrane
protein ) gene detected in all E.coli serogroups that isolated , stx1 gene not detected in all E. coli
sergroups that isolated ,but stx2 gene detected in O₁₁₄ and O₁₂₈.