Purification and Characterization of 221, the Cationic Peptide that Inhibits Staphylococcus aureus

Abstract

Bacteriocin-like inhibitory substances (BLISs) that are produced by various species of Staphylococcus spp., could have potential as topical therapeutic agents for treating highly drug-resistant staphylococcal infections. The spectrum of activity of some such agents, recently identified in our laboratory, has been characterized. This was carried out at different temperatures using deferred antaonism assay. The biological activity of 221, which produced by S. epidermidis strain 221 and shows activity against Epidemic MRSA-15 and strains of MSSA, is described in detail. The initial characterization of this agent showed that its activity is stable on plates pre-exposed to high temperatures (70-80oC/30-40mins) and displaying specificity for S. aureus. This suggests that BLIS 221 is a bacteriocin in nature, possibly of Class-I.