E. Coli

3.2. Methods
3.2.1. Collection of sample:
The birds were collected every week, starting from 8 days of a
arrival till the marketing age 38 day old. The source of birds was from
18 broiler farms in Dakahlia governorate.
3.2.2. Isolation of Enterbacteriaceae from organ samples:
Firstly, chickens were scarified, dipped in phenol 5%solution,
opened aseptically for bacteriological examination, the macroscopic
lesions were sterilized using preheated scalpel. Then separate loopfuls
were taken from heart blood, liver, lung, gall bladder (Siam, 1998).
Each separate loopful was directly inoculated into separate nutrient
broth tubes, then subcultured into MacConkey broth and MacConkey
agar. The inoculated broth and the streaked agar media were incubated
at 37°C for 24-48 hours pure colonies were picked up and preserved
onto slope agar for further biochemical and serological identification
according to Edwards and Ewing (1972), Finegold and Martin
(1982), Krieg and Holt (1984) and Holt et al., (1999).
3.2.3. Isolation of Enterobacteriaceae from urine samples
Urine samples were collected from private laboratories. Firstly,
isolation was done by soaking a cotton swap in the specimen then
streaked on nutrient agar media then it was incubated in incubator at
37°C for 24 hours. After growth the pure colonies were picked up and
streaked on MacConkey agar media and incubated at 37°C for 24
hours then the suspected colonies were picked up and streaked onto
nutrient agar plates for purification then subjected to biochemical and
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