AGAROSE-GEL ELECTROPHORESIS AND RESTRICTION ENDONUCLEASE ANALYSIS OF LARGE STAPHYLOCOCCUS PLASMIDS

Preliminary studies using an improved method for the agarose gel electrophoresis of semipurified, cleared lysates of staphylococci have indicated some distinct differences in plasmid composition between the coagulase-positive species Staphylococcus aureus and Staphylococcus intermedius, and various coagulase-negative species. Penicillinase-positive strains of S. intermedius and S. simulans did not carry large penicillinase plasmids like most penicillinase-positive strains of S. aureus. Most coagulase-negative species examined demonstrated complex plasmid profiles. Codigestion by the restriction endonucleases HaeIII and HpaI offered a useful approach for fingerprinting" large plasmids from various strains and species. © 1979 Springer-Verlag New York Inc."