Plasmid Involvement in Production of and Immunity to the Staphylococcin-like Peptide Pep 5

Abstract

The staphylococcin-like peptide Pep 5 is produced by the penicillin resistant strain Staphylococcus epidermidis 5. This strain is immune to the peptide. Plasmid analysis of S. epidermidis 5 by agarose gel electrophoresis and EM demonstrated 5 plasmids with MW ranging from 5.8 .times. 106-29 .times. 106. Variants of S. epidermidis 5 not producing Pep 5 or which had become penicillin sensitive were induced by various curing treatments. Strains lacking the 13.9 .times. 106 MW plasmid (pED502) had lost penicillin resistance, and those lacking the 12.3 .times. 106 MW plasmid (pED503) failed to product Pep 5. pED503 is also responsibe for the immunity of the producer cell to Pep 5. Plasmid pED502 could be transformed into S. aureus RN 981 which then became resistant to penicillin. pED503 could not be transformed into S. aureus RN 981, but could be transformed into S. epidermidis 5 variants previously cured of this plasmid; the transformants then regained the properties of Pep 5 production and immunity.