الفهرس 
IntroductionOnly 14 pages are availabe for public view
 |  | from | 109 |  |  |
| | | from | 109 | | |
Abstract
Colibacillosis causes a huge economic loss in poultry farm. It caused by one of the most prevalent extraintestinal pathogenic E. coli (ExPEC), which cause infections outside of the gastrointestinal tract. The development and spread of gram-negative bacteria that are resistant to carbapenem represent a severe threat to human health. Nothing is currently known about the molecular processes that lead to carbapenem resistance and the prevalence of APEC in Egypt. Detection of carbapenem resistance genes, virulence-associated genes among APEC and profiling antimicrobial susceptibility in bacteria have been considered as an important work to recognize the pathogenesis and possible hazards of anti-microbial resistance of APEC. Colibacillosis can be prevented and controlled using antibiotics to treat the bacterial infections and to eliminate some predisposing causes. Therefore, restriction in antimicrobials use in poultry farms among veterinarians is highly recommended to control the spread of antimicrobial-resistant bacteria among poultry farm. A total of 100 organ tissue samples were collected. Forty isolates were confirmed to be E. coli. The recovery rate of E. coli from different chicken samples was 10%, 22.5%, 22.5%, 25%, and 20% form lungs, liver, spleen, intestinal contents and yolk sac respectively. Samples were subjected to conventional culture technique for isolation of E. coli. E. coli isolates were serotyped into 20 serotypes, O78, O1, and O2 were the most prevalent serotypes with an incidence of 20%, 15%, and 15%. Polymerase chain reaction (PCR) was used for detection of APEC virulence genes (hlyA, iutA, ompT, iss, iorN) and six carbapenem- resistant genes namely, (blaIMP, blaVIM, blaKPC, blaOXA-48 blaGES blaNDM. ) Among them, 5 APEC virulence- genes were detected from all isolates. The confirmed E. coli were subjected to disc diffusion method for detection their susceptibility to antimicrobials. The tested isolates exhibited a remarkable resistance to ampicillin (97.5%), cefuroxime (92.5%), clindamycin (90%), chloramphenicol (62.5%), doxycycline (45%), amikacin (25%) and ciprofloxacin (12.5%). While, the retrieved isolates displayed 100 % sensitivity against imipenem, meropenem, ertapenem, ceftazidime and colistin. Concerning carbapenemase-encoding genes, blaIMP, blaVIM, blaKPC, blaOXA-48, blaGES couldn’t be detected among the E. coli isolates while, blaNDM was confirmed in three isolates.