Plasmid-Mediated Production of Staphylococcin in Bacteriophage Type 71 Staphylococcus aureus

Staphylococcin production by Staphylococcus aureus strain C55 was eliminated when producing strains were exposed to various curing treatments. Acridine orange, ethidium bromide, and sodium dodecyl sulfate each effected less than 15% cure rates in treated cells. Rifampin eliminated the staphylococcin in 83% of treated isolates, and growth at 42 C resulted in a 97% cure rate. Curing of staphylococcin production and elimination of penicillinase plasmid were independent of one another. Several characteristics of the cured strains were examined and compared with the bacteriocin-producing strains. Whereas bacteriocin-producing cells were resistant to the bactericidal action of the staphylococcin and failed to adsorb it, cured cells adsorbed the staphylococcin and were susceptible to its lethal effect.