Phage Taxonomy: We Agree To Disagree

Bacteriophage (phage) researchers are in universal agreement that phage biology has undergone a renaissance in recent years. No longer just tools of molecular biology, phage are now recognized to play critical roles in bacterial pathogenesis (3, 29) and bacterial population dynamics (5, 10). Likewise, phage therapy is enjoying renewed interest in Western medicine (24). Phage-derived proteins are currently being used as molecular machines (23), diagnostic agents (22), and therapeutic agents (15, 17, 22) and for drug discovery (14). However, the resurgence in phage popularity has only fanned the flames of an ongoing debate, namely, that of phage taxonomy. Many phage biologists feel that the current taxonomic classification scheme, devised over 3 decades ago by the International Committee on Taxonomy of Viruses (ICTV), is outdated and in need of revision in light of the postgenomic age. However, choosing one methodology on the basis of which to classify all known and yet to be discovered phage is an area where phage researchers agree to disagree. In this issue of the Journal of Bacteriology, Chibani-Chennoufi et al. provide support for a comparative genomics-based alternative classification scheme (6).