E. Coli

6- Urease test
The test determine the ability of bacteria to decompose urea by means
of urease enzyme. The development of red colour indicates hydrolysis of
urea.
7- Sugar fermentation test
The isolated organisms were cultured into sugar media containing 1%
of the tested sugar. Phenol red act as indicator. Yellow colour indicate acid
production while gas production seen in Durham’s tubes, after incubation
at 37°C for 1-7 days.
3.2.4. Serological identification of E.coli :
Serological analysis was performed according to methods described by
Edwards and Ewing(1972).
1- O antigen group screening:
a-Slide agglutination test:
A glass pencil was used to divide a glass slide into 2 parts, one drop of
the polyvalent sera and one drop of the polyvalent sera and one drop of the
physiological saline were separately placed in the 2 section.
Each isolate was densely suspended in physiological saline. One
drop of the suspension, using the platinum loop, was placed in each
separate section of the slides in the vicinity of polyvalent sera and
physiological saline. The antigen and the serum drop were mixed in each
section.
The glass slides were titled back and front only strong agglutinations
occurring within one minute were accepted as positive, when positive
reaction was observed with one of the polyvalent sera, slide agglutination
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