<i>vfr</i> , a Novel Locus Affecting Cysteine Protease Production in <i>Streptococcus pyogenes</i>

Abstract

A gene unique to Streptococcus pyogenes, called vfr, that negatively regulates speB, an important extracellular proteinase, has been identified. Disruption of vfr markedly increased SpeB production in a clinical strain of S. pyogenes and relieved its growth phase dependency. These findings may provide important insights into the pathogenesis of invasive S. pyogenes infections.