Escherichia coli (E. coli) is one of the most important causes of gastrointestinal diseases in developing countries. It
considered the third cause of diarrhea in children. In this study, bacteriophages were isolated and detected from wastewater
against isolates of E. coli by using plaque and spot test assay. Characterized three phages were differed on plaque
morphology, particle morphology, host range and titration. According to phage characterization, the three phages were
classified into two from Siphoviridae and one from Podoviridae. Combinations of the bacteriophages had broad host range
with strong lytic activity against pathogenic E. coli. Phage cocktail revealed high stability at 45°C, pH 9 and 20% of salt
concentration. According to the previous characters of a phage cocktail properties can broaden the spectrum of application of
phage therapy. Formulated phages were prepared by mixing phages with royal gelly, dried skimmed milk and a mixture of
sucrose and corn flour at ratio 1:1(V: W) at phage cocktail concentration 2.2x1011 plaque forming units (pfu) per mL. These
phages formulation remained active for at least 48 days when stored at 4°C in a light protected container with titres of
4.0x1010, 3.6x1010 and 3.4x1010 pfu/mL for royal gelly, dried skimmed milk and a mixture of corn flour and sucrose
respectively.