FIG 1.

Unrooted phylogenetic tree of the 17 sequenced isolates and a representative cos (DT1), pac (TP-J34), 5093 (5093), and 987 (9871) groups included as references. All phage isolates group most closely to DT1, while distinct subgroups or lineages (L) of the phage isolates are also highlighted in the tree (L1 to L4). Factory-derived phage isolates are indicated in black text, externally derived phage isolates are indicated in green text, and representatives of the four S. thermophilus groups (cos, pac, 5093, and 987) are indicated in blue text.