PBP4 Mediates β-Lactam Resistance by Altered Function

Abstract

Penicillin binding protein 4 (PBP4) can provide high-level β-lactam resistance in <i>Staphylococcus aureus</i> A series of missense and promoter mutations associated with <i>pbp4</i> were detected in strains that displayed high-level resistance. We show here that the missense mutations facilitate the β-lactam resistance mediated by PBP4 and the promoter mutations lead to overexpression of <i>pbp4</i> Our results also suggest a cooperative interplay among PBPs for β-lactam resistance.