Whole-genome sequencing and gene mapping of a newly isolated lytic enterococcal bacteriophage EFRM31.

Bacteriophages contribute greatly to bacterial evolution. There has been limited investigation of enterococcal bacteriophages, and only two enterococcal bacteriophages have been sequenced completely. In this study, a novel enterococcal bacteriophage, EFRM31, was isolated from a piggery effluent sample and then characterized. The complete bacteriophage genome was determined by shotgun sequencing. EFRM31 belongs to the family Siphoviridae (order Caudovirales) and has a circular double-stranded DNA genome. The putative EFRM31 genome consists of 16945 nucleotides with a low GC content (34.5%) and does not contain CpG islands. The EFRM31 genome contains 82 putative open reading frames, including 17 with identities to genes required for the assembly of a head-tail bacteriophage and 6 hypothetical proteins of unknown function. In general, the sequencing results from EFRM31 revealed considerable similarity to another enterococcal bacteriophage, EFAP-1. This identity and the order of shared genes suggest a close relationship or a common ancestor for these two bacteriophages.