الفهرس 
introductionOnly 14 pages are availabe for public view
 |  | from | 156 |  |  |
| | | from | 156 | | |
Abstract
Escherichia coli is a diverse species. Some strains are part of the natural intestinal flora, while others may cause diseases. Certain Escherichia coli strains may cause intestinal or extraintestinal infections in humans and in domestic animals. In poultry, pathogenic E.coli strains usually induce extraintestinal infections which are manifested as generalized infection, swollen-head syndrome and cellulitis.
Cellulitis is a condition commonly seen in meat-type poultry at processing characterized by extensive lesions of the cutis and subcutaneous tissue resulting of extensive economic losses, Therefore the present study was planned to gain more about characteristics of E.coli isolated from cellulitis lesions of broiler chickens, phenotypically and genotypically.
A total of (103) defeathered broiler carcass with gross skin lesions were collected during inspection process of different flocks in slaughter houses at Ismailia province.
The obtained results can be summarized as followings:
1- The bacteriological isolation and biochemical identification were done for all samples, about (51/103) 49.51% of the isolates were positive for E.coli isolation.
2- Serotyping was applied to 35 isolates of E.coli and they were serologically belonged to O44 which was the highest serotype identified (3; 8.57%) followed by O55, O158 and O169 (2 for each by 5.71%) followed by O119 and O125 (one for each by 2.86%).
3- Large group of isolates were untypable (68.57%).
4- PCR assay was carried out for three serotypes (O125, O158 and O169) and two untypable strains to detect the presence of specific gene of E.coli (phoA). All isolates (100%) were phoA gene positive.
5- The five E.coli isolates (O125, O158, O169 and 2 untypable strains) were subjected for the detection of the virulence other 8 genes (iss, iutA, tsh, kpsMTII, papC, stx1, traT and cvaC). It was found that O125, O158 and untypable (No. 2) isolates were positive for iss, iutA, kpsMTII, papC, traT and cvaC, respectively, followed by untypable (No. 1) isolate was positive for iss, iutA, kpsMTII, papC and traT, respectively, while O169 serotype was only positive for tsh, papC and cvaC.
6- stx1 gene was not identified in the five examined E.coli isolates.
7- So concerning the prevalence of virulence genes detected by cPCR among five E.coli strains, it was found that all isolates (100%) were traT and papC genes positive, 80% of isolates were iss, iutA and kpsMTII genes positive, 60% of isolates was cvaC gene positive and 20% of isolates was tsh gene positive. While none of isolates (0%) carried stx1 gene.