Reverse Transcriptase-Mediated Tropism Switching in Bordetella Bacteriophage

Abstract

Host-pathogen interactions are often driven by mechanisms that promote genetic variability. We have identified a group of temperate bacteriophages that generate diversity in a gene, designated mtd (major tropism determinant), which specifies tropism for receptor molecules on host Bordetella species. Tropism switching is the result of a template-dependent, reverse transcriptase–mediated process that introduces nucleotide substitutions at defined locations within mtd . This cassette-based mechanism is capable of providing a vast repertoire of potential ligand-receptor interactions.