title: Evolution of a Lytic Bacteriophage via DNA Acquisition from the Lactococcus lactis Chromosome.
abstract: We discovered a phage-host interaction in which the lytic phage ul36, in response to pressure exerted by an abortive phage resistance mechanism, acquired a large DNA fragment from the chromosome of Lactococcus lactis NCK203 to form a new phage, ul37. Phage ul37 was characterized at morphological, phenotypic, and genotypic levels and was found to be a member of the P335 species. Although it exhibits a high level of DNA homology with ul36, phage ul37 is resistant to the abortive mechanism and has a longer tail, a different base plate, and apparently a different origin of replication. The chromosomal DNA implicated in the formation of new phage ul37 was disrupted by site-specific integration in NCK203. This strategy prevented the appearance of ul37 during subsequent infections with ul36.
authors.affiliation: Department of Food Science and Southeast Dairy Foods Research Center, North Carolina State University, Raleigh, North Carolina 27695-7624.
authors.forename: S
authors.initials: S
authors.lastname: Moineau
authors.forename: S
authors.initials: S
authors.lastname: Pandian
authors.forename: T R
authors.initials: TR
authors.lastname: Klaenhammer