Genomic Analysis of a Novel Active Prophage of Hafnia Paralvei

Abstract Relatively little is known about the prophages in Enterobacterales bacteria except Escherichia coli. A novel phage, Hafnia phage yong2, was induced from Hafnia paralvei by mitomycin C. The phage has an elliptical head of approximately 45 × 38 nm, a long noncontractile tail of approximately 157 × 4 nm. The complete genome of Hafnia phage yong2 is a 39,546 bp double-stranded DNA with a G+C content of 49.9%, containing 59 opening reading frames (ORFs), and having at least one fixed terminus (GGGGCAGCGACA) with R=107>100. In phylogenetic analysis, Hafnia phage yong2 clustered with 4 predicted Hafnia prophages and 1 predicted Enterobacteriaceae prophage. The prophages cluster and Drexlerviridae family together formed two distinct subclades nested within a clade, suggesting the existence of a novel class of prophages with conserved sequences and unique evolutionary status not yet studied before in Hafniaceae and Enterobacteriaceae bacteria.