CHARACTERIZATION AND GENOMIC ANALYSIS OF TWO ESCHERICHIA COLI O157:H7 BACTERIOPHAGES ISOLATED FROM PIGEONS

Enterohemorrhagic Escherichia coli, also known as EHEC, is a subset of Shiga toxin-producing E. coli (STEC), and it has recently been identified as one of the principal foodborne pathogens. E. coli O157:H7 is the most important serotype of STEC for its role in causing foodborne illnesses. E. coli O157:H7 could cause various gastroenteritis symptoms such as diarrhea, hemolytic uremic syndrome, hemorrhagic colitis, and thrombotic thrombocytopenic purpura and may cause death. Elimination of E. coli O157:H7 during food processing and storage is a possible solution. Bacteriophages have a significant impact on bacterial populations in nature due to their ability to lyse their bacterial host. All E. coli O157:H7 phages that have been previously announced were found in ruminants or swine. Here, I studied the characterization and genomic analysis of two lytic E. coli O157:H7 bacteriophages isolated from feaces of wild pigeon; UAE MI- 01 and Ec_MI-02. This is the first time to report E. coli O157:H7 phages from birds feaces. UAE_MI-01 belonged to the family Siphoviridae in order Caudovirales. UAE_MI-01 had a with a burst size of almost 100 plaque-forming units (PFU) per host cell after a latent period of 20 min and an adsorption rate constant (K) of 1.25 × 10−7 mL/min. UAE_MI-01 was found stable at a wide range of temperature, pH and some of the common laboratory disinfectants. The 44,281 bp-long genomes of the phage had an average GC content of 54.7%. On the other hand, Ec_MI-02 belonged to genus Tequatrovirus in the order Caudovirales. The K value of Ec_MI-02 was found to be 1.55 × 10−8 mL/min. The latent period was almost 50 min with burst size of almost 10 PFU /host cell. Ec_MI-02 was stable at a wide range of pH, and temperature and was resistant to ethanol 70%. Its genome was made of 266 genes with total 165454 bp and average GC content of 35.5%. It is