Abstract: Three coliphages designated ECP1, ECP2 and ECP3 were identified in this study. Also, the effect of some physical factors on the infectivity of these coliphages was studied. The three coliphages were tested for their infectivity using the indicator bacterial strains E. coli W1 and E. coli W2 where coliphage ECP1 was highly specific to infect E. coli W1, on the other hand, coliphages ECP2 and ECP3 were highly specific to infect E. coli W2. The three coliphages were very sensitive to heat inactivation no survivors could be recorded after 10 min of exposure time up to 60°C. Also, the profile of the three coliphages inactivation after different time intervals exposed to UV-irradiation at different heights of 15 and 30 cm from the irradiation source was examined. Increased UV-irradiation doses decreased the plaque numbers of the three coliphages tested. The effect of different pH values on stability of the three coliphages was also tested. Maximum stability was observed at pH 6.0. The viabilities of the three coliphages were rapidly decreased towards alkalinity compared to pH 6.0. The ability of the three coliphages to form plaques at preservative temperature range 3-5, 25-28 and 35-37°C was examined. The suitable storage temperatures for the three coliphages were 3-5 and 25-28°C.
Gamal Enan, Khalid A. Shaaban, Ahmed Askora and Muhammad Maher, 2013. Coliphages Lysing Escherichia coli Bacteria: Their Morphology and Their Response to Some Physical Factors. Research Journal of Applied Sciences, 8: 516-522.