The spectrum of strains of a species of bacterium that can be infected by a given strain of phage. The first mutations to be identified in phage involved host range. The term is used more generally to refer to the group of species that can be attacked by a given parasite. Some bacteria can parasitize certain mammals, but only at specific developmental stages. For example, the K99 strain of E. coli can infect calves, lambs, and piglets, but not adult cattle, sheep, and swine. The resistance shown by the adult farm animals is due to the replacement of cell surface receptors by molecules to which the bacterium does not bind. See Chronology, 1945, Luria; Duffy blood group gene.
Subjects: Genetics and Genomics.