The genomes of bacteriophages vB_YenM_TG1 (TG1) and vB_YenM_phiR1-RT (phiR1-RT), isolated from pig manure in Canada and sewage treatment plant in Finland, consist of linear double-stranded DNA of 162,101 and 168,809 bp, respectively. They share 91% overall nucleotide identity and 89.7% homologous proteins. Based on phylogenetic analyses of their whole genome sequences and large terminase subunit protein sequences, a genus named Tg1virus within the family Myoviridae is proposed with TG1 and phiR1-RT as member species.
These lytic bacteriophages exhibit a host range restricted to Yersinia enterocolitica, and display activity against the epidemiologically significant serotypes O:3, O:5,27, and O:9. Using transposon mutagenesis we have isolated host mutants and demonstrated that TG1 and phiR1-RT phages use both the lipopolysaccharide (LPS) inner core heptosyl residues and the outer membrane protein OmpF as phage receptors. In addition, when three phiR1-RT resistant mutants were sequenced, the phage genome was found in one scaffold in all three, i.e. plasmid? Apparently phiR1-RT was able to enter into pseudolysogenic state.