LOCALIZATION OF PROPHAGES OF SEROLOGICAL GROUP-B AND GROUP-F ON RESTRICTION FRAGMENTS DEFINED IN THE RESTRICTION MAP OF STAPHYLOCOCCUS-AUREUS NCTC-8325

Several Staphylococcus aureus strains were lysogenized by the phages o f serological group B (phages phi 53, phi 85) as well as by some of se rological group F (phages phi 77, phi 84) and macrorestriction fragmen t patterns of genomic DNA were estimated in the lysogenized, non-lysog enic and delysogenized (cured of prophages) strains. It was shown that the integration of phage DNA into chromosome of S. aureus leads to sp ecific 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 defi ned 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 fr agment E of the S. aureus restriction map. The prophages of strain NCT C 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 genet ically related to phages of serological group A and phage phi J to tho se of serological group F. Evidence was given that lysogenization of S . aureus strains by at least four prophages does not cast any doubt up on the estimation of their genetic relatedness based on their similari ty in restriction pattern.