Jacobs Journal of Genetics

Detection of Virulence-Associated Genes of Avian Pathogenic Escherichia Coli (APEC) Isolated from Broilers

*Iman Ibrahim Shabana
Department Of Bacteriology Immunology And Mycology, Egypt

*Corresponding Author:
Iman Ibrahim Shabana
Department Of Bacteriology Immunology And Mycology, Egypt

Published on: 2017-12-13


Escherichia coli is responsible for significant losses in the poultry industry. This study aimed to determine the prevalence, serotypes, the virulence-associated genes and the antimicrobials susceptibility of avian pathogenic E. coli (APEC) strains. A total of 1200 samples were collected from 200 birds (60 recently dead, 80 diseased and 60 apparent healthy broilers). Standard disc diffusion method used for determination of antimicrobials susceptibility. PCR used for the detection of virulence genes. Bacteriological examination revealed that E. coli was recovered from 842 samples with overall prevalence of 70.16%. Incidence of E. coli from fresh heart blood samples was 75%, from liver 83%, from kidney 64%, from spleen 57%, from small intestine74.5% and from bone marrow was 67.5 %. E. coli isolates belonged to Serotypes O111, O44, O55, O142, O128, O158, O157, O29 and O115. The antimicrobials susceptibility profile of the isolates showed resistance to Ampicillin, Neomycin, Doxycycline and Oxytetracycline, while ciprofloxacin and Erythromycin were effective against the isolates. PCR assay was carried out to detect the presence of phoA, iss and iutA gene, all serovars had the three genes except (O29) not possess iss gene. High prevalence of multidrug resistant avian pathogenic Escherichia coli (APEC) among broilers.


APEC; Broilers; Egypt


Escherichia coli is a normal microflora of the intestinal tract and in the bird’s environment, only certain of these strains possessing specific virulence attributes, designated as avian pathogenic E. coli (APEC), are able to cause disease. APEC is mostly associated with extra intestinal infections, namely colibacillosis [1-3]. Colibacillosis refers to any localized or systemic infection caused entirely or partly by E. coli including colisepticaemia, coligranuloma, chronic respiratory disease (CRD), peritonitis, swollen-head syndrome, Artheritis, synovitis, panophthalmitis, perihepatitis and pericarditis [4]. APEC are mostly associated with infection of extra intestinal tissues in chickens, turkeys, ducks and other avian species with the exception of a possible relationship with the development of enteritis. The most important disease syndrome associated with APEC begins as a respiratory tract infection and may be referred to as aerosacculitis or the air sac disease.