Isolation, characterization and whole genome analysis of a novel Escherichia phage Tequintavirus GN06 

Abstract Escherichia coli O114:K90(B) is a kind of enteropathogenic E. coli (EPEC). It can cause severe diarrhea and even septicemia in Aquaculture. With the incidence of antibiotic resistance reaching crisis point, it is important to find alternative treatments for multidrug-resistant infections. Using phages for pathogen control is a promising treatment option to combat bacterial resistance. In this study, a lytic phage, named as GN06, was isolated from sewage. It can efficiently lytic E. coli O114:K90(B). Transmission electron microscopy showed that the phage belongs to the Siphoviridae. Phage GN06 has a linear, double-stranded DNA genome of 107,237 bp with a GC content of 39.2% and 155 coding sequences. Cages belonging to the genus Tequintavirus and could be classified as a T5-like virus. BLASTn analysis revealed that phage GN06 shares 94.07% identity (88% genome coverage) with an unpublished Escherichia phage vB_EcoS_HASG4. Moreover, the highest average nucleotide identity (ANI) values of phage GN06 with all the known phages was 0. 83, suggesting that GN06 was a relatively novel phage. Temperature and pH stability tests showed that phage GN06 was stable from 4℃ to 60℃and pH range from 5 to 9. These results suggested that phage GN06 with unique genomic features and high tolerances of pH and temperature had the potential of controlling bacteria pathogens. Therefore, GN06 has the potential to serve as a novel candidate for phage therapy.