A total of 120 broiler chickens (76 diseased living and 44 freshly dead), 2 - 8 weeks old were collected from different localities in Egypt ( Giza, Kaliobyia, Monofyia, Dakahlyia, Sharkyia, Kafr El-sheikh and Behyira ).The internal organs " heart, liver, bone marrow, spleen and kidney" were collected from the examined broilers. The percentage recovery rate of E. coli
from broiler chicks was (18.33%). The antimicrobial sensitivity for the recovered isolates against 10 antibiotic agents revealed that resistance to Doxycycline was (100%), Amoxicillin (90.91%), Ciprofloxacin (86.37%), Gentamycin (81.82), Sulfamethoxazole/Trimethoprim (77.27%), Chloramphenicol (72.73%), Danofloxacin (68.18%), Nitrofurantoin (68.18%), cefotaxime (40.91%) and Colistin sulphate (27.27%). The molecular characterization of some ESβL genes (blaTEM, blaCTX, blaCMY1, blaSHV and blaOXA1) in the plasmid of the isolated pathogenic E. coli revealed that blaTEM, blaCTX and blaSHV genes detected in 18/22 isolates at a percentage of 81.82%, while blaCMY1 and blaOXA1 could not be detected. Meanwhile none of these genes could be recovered from the chromosomal DNA of the examined isolates. This study suggests
that emergence of ESβL Colisepticemic E.coli magnify the disease condition and failure of control.