CES1 and escherichia coli infection: Based on the criteria of EOP values, phage CE1 could lyse 56.9% (33/58) of high pathogenic APEC strains listed in Table 1, of which phage CE1 had a high lytic activity of 20.7% (12/58), a medium lytic activity of 19.0% (11/58), and a low lytic activity of 17.2% (10/58), indicating that phage CE1 could potentially control colibacillosis caused by high pathogenic APEC strains due to its relatively wide host range.