Localization of prophages of serological group B and F on restriction fragments defined in the restriction map of Staphylococcus aureus NCTC 8325.

Several Staphylococcus aureus strains were lysogenized by the phages of serological group B (phages phi 53, phi 85) as well as by some of serological group F (phages phi 77, phi 84) and macrorestriction fragment patterns of genomic DNA were estimated in the lysogenized, non-lysogenic and delysogenized (cured of prophages) strains. It was shown that the integration of phage DNA into chromosome of S. aureus leads to specific changes in restriction fragment pattern in all the lysogenized strains. These changes correlate well with the SmaI restriction map of S. aureus NCTC 8325 since they concern the restriction fragments defined in this map. Phages phi 53 and phi 85 integrate into SmaI fragment B. On the other hand, phages phi 77 and phi 84 integrate into SmaI fragment E of the S. aureus restriction map. The prophages of strain NCTC 8511 have their integration sites, as follows: the phage designated by us phi M integrates in fragment A, whereas the integration site for phage phi J lies in fragment E. Phage phi M was estimated to be genetically related to phages of serological group A and phage phi J to those of serological group F. Evidence was given that lysogenization of S. aureus strains by at least four prophages does not cast any doubt upon the estimation of their genetic relatedness based on their similarity in restriction pattern.