Two Restriction and Modification Systems in Staphylococcus aureusnctc8325 Iordanescu, S. and Surdeanu, Marietta,, 96, 277-281 (1976), doi = https://doi.org/10.1099/00221287-96-2-277, publicationName = Microbiology Society, issn = 1350-0872, abstract= SUMMARY: The presence of two distinct host specificities in Staphylococcus aureus strain nctc8325 was revealed by the isolation of restriction- and modification-deficient mutants. The two host specificity systems, designated S1 and S2, are both active on phage 80μ α but are not additive in their restricting activity. Restriction-deficient, modification-proficient mutants were invariably affected in both restriction systems. The functional relationship between these two systems is discussed., language=, type=