Objectives: To characterize morphological, physicochemical and genomic features of a novel virulent coliphage which was isolated from an engineered Escherichia coli culture and termed engineered E. coli phage (EEP).
Methods and results: Electron microscopy revealed that EEP has an icosahedral head (62 nm in diameter) and a long, flexible tail (138 nm in length). EEP was able to infect all 10 engineered E. coli strains kept in our laboratory, showing a strong ability to lyse engineered E. coli. Sequencing of the EEP genome revealed a double-stranded DNA (39.8 kb) with 54.72% GC content. Fifty-two open reading frames were predicted to be coding sequences, 18 of which were functionally defined and organized in a modular format, which includes modules for DNA replication, DNA packaging, structural proteins and host cell lysis. This phage could not be inactivated at 90 degrees for 45 min and was resistant to ethanol and alkali treatment. EEP is assigned to the Siphoviridae family based on its morphological, genomic and physicochemical properties.
Conclusions: A novel coliphage was isolated from engineered E. coli strains, and its morphological, genomic and physicochemical properties were characterized, which will improve our knowledge of bacteriophage diversity.