Phenotypic characterization of escherichia coli isolated from broiler chiken

الملخص EN

E.

coli is one of the most common isolates in avian diseases, which causes colibacillosis.

In this study a total of 114 E.

coli isolates were recovered from 500 chicken samples including heart, liver and rectal swabs samples with a percentage of 12.8 %.

from broilers with a history of respiratory manifestations and postmortem lesions (pericarditis, per hepatitis and air saculitis) in Sharkia province.

The recovered E.

coli isolates were typed serologically into 10 different 'O' groups including O1, O2, O26, O44, O78, O91, O111, O121, O125 and O128.

Untypeable isolates were also recovered.

The results of congo red test revealed that (40 / 500) of E.

coli isolates from rectal swabs were positive.

The susceptibility of identified E.

coli isolates to a panel of seventeen commonly used antimicrobial agents and E.

coli isolates showed the the highest resistance against lincomycin (100 %), tetracycline (96.8 %), streptomycin (93.7 %), trimethoprim sulfamethoxazole, ampicillin, erythromycin and florfenicol (92.18 %), which being the least effective antimicrobial agent aganist E.

coli, while the least resistance rate was detected against apramycin (32.18%).