Five Distinctive Phages from an Egyptian Industrial Strain of Bacillus thuringiensis subsp. aegypti

The production of the biocontrol agent, Bacillus thuringiensis (Bt) subsp. aegypti C18 (BtaC18), suffers huge economic losses due to phage infection. To improve it, an isolation and characterization of the causative agent are necessary, using gradient centrifugation, electron microscopy and protein analysis. Five morphologically distinctive phages were isolated from the strain belonged to the order Caudovirales. Moreover, they been classified: Tailed group (TP3-01, TP3-02, TP3-03 and TP3-05) and pseudotailed group (TP3-04) and fell into three families: Siphoviridae, Tectiviridae and Podoviridae. Result shows that TP3-01, TP302 and TP3-03 are members of the Siphoviridae family, TP3-04 belongs to Tectiviridae and TP3-05 is a member of Podoviridae. In conclusion, BtaC18 was the host of at least five morphologically diversified phages which needs a lot of work to make a phage resistant bacterium.