Molecular evidence for the lysogenic state of microorganisms belonging to the genus Bordetella and characterization of Bordetella parapertussis temperate bacteriophage 662-2

A new bacteriophage ?K of microorganisms belonging to the genus Bordetella was isolated from cells of the earlier characterized strains 66_2-2 (1 and 2) obtained upon phage conversion of B. parapertussis 17 903 cells by B. pertussis bacteriophage ?134. Bacteriophage ?K is identical to previously described Bordetella bacteriophages ?T, ?134, and ?214 in morphology and some biological properties but has a permuted genome different from all other phages. DNA of bacteriophage ?K is not integrated in the chromosome of B. parapertussis 17 903, similar to DNA of bacteriophages ?T, ?134, and ?214 that are not integrated into B. pertussis and B. bronchiseptica chromosomes, but may be present in a small part of the bacterial population as linear plasmids. Sequences homologous to DNA of bacteriophage ?K were detected in the chromosome of strain 66_2-2 (1 and 2) and in chromosomes of all tested strains B. pertussis and B. bronchiseptica. Prophage integration in chromosomes of microorganisms of the genus Bordetella may vary in different bacterial strains and species. An assumption about abortive lysogeny of B. parapertussis bacteria for ?K phage and of B. pertussis and B. bronchiseptica for closely related phages ?T, ?134, and ?214 has been advanced. The possibility of involvement of B. pertussis insertion sequences in the formation of the chromosomal structure in 66_2-2 convertants and in phage genomes is considered.