MOLECULAR IDENTIFICATION OF VIRULENCE PROPERTIES AND VIRULENCEASSOCIATED GENE (ISS) OF E. COLI ISOLATED FROM BROILER CHICKS

Abstract

The present study identified virulence genes for existence of virulence genes increased the serum survival (Iss) for determining the pathogenicity regarding E. coli in broiler chicks. The results indicated that 45 (36.7%) of the 120 samples collected from dead and morbid broiler chicks that have been infected with E. coli, and the difference between non-pathogenic and pathogenic was investigated. Hemolysin production, motility, and the agglutination test have been also shown to be positive. In vitro tests revealed that three isolates have been classed as moderately, highly, and slightly virulent, based on their pathogenicity features. Broiler chicks have been typified by the monovalent antisera had indicated that (31.74%) have been identified as E. coli serotype O2. Slightly and highly pathogenic isolates have been responsive to chloramphenicol, penicillin, gentamicin, and streptomycin, while moderately pathogenic isolates have been only susceptible to the gentamicin and chloramphenicol. The use of the PCR as a valid approach for detecting virulence genes resulted in an increase in serum survival (Iss) in 15 (65.2%) of the total sample