Isolation and Identification of E-coli from Infected Cases from Broilers Farms in 2019

E. coli infections are responsible for great economic loss and causing a serious threat to the poultry industry. One hundred and fifty samples were collected from different poultry farms for isolation of E.coli bacteria. Different percentage rates were 6%, 8.6% and 5.3 obtained from apparently healthy birds, freshly dead and diseased birds respectively. Thirty E.coli isolates were identified as (O1, O2, O6, O78 and O157). E.Coli serotypes lethality tests in chicks showing clinical signs which appeared on the 5th day and the mortalities recorded at the 7th day post infection with percentage 7% of the challenged group. Lethality tests in mice showed mortality 100% at 3rd day post challenge in pathogenic serotypes. Molecular characterization was done for detection of iss, ombA, fimH, iroN and pabC virulence genes for E.coli serotypes. All isolates were positive for all genes except papC was negative. Antibiotic susceptibility test was applied for all for detection of the suitable antimicrobial agent in the infected poultry farms with E.coli in which all isolated serotypes were sensitive to cefatriaxone, tobramycin except O6 and were intermediate, with spectinomycin, amikacin and fosfomycin. Recently isolated serotypes may help in local vaccine production.