Provides comprehensive and accessible information in following areas: phage-bacteria interactions including: lysogeny, lysogenic conversion, and phage directed host cell lysis; phage regulatory circuits that control virulence gene expression; evolutionary forces in selection and maintenance of phages bearing virulence genes; phage contributions to pathogenicity of E. coli, Salmonella, Mycobacteria, Vibrio, Bordetella, Corynebacterium, Staphylococcus, Streptococcus, Pneumococcus, Mycoplasma, and Listeria; applied phage technologies, including high frequency recombination and phage display; critical analysis of phage therapy.