Streptolysin O Deficiency in Streptococcus pyogenes M1T1 <i>covR/S</i> Mutant Strain Attenuates Virulence in <i>In Vitro</i> and <i>In Vivo</i> Infection Models

Abstract

-knockout mutants, we investigated the role of SLO in virulence. We found that SLO alters interactions with host cell populations and increases Strep A viability at sterile sites of the host, such as the blood, and that its absence results in significantly less virulence. This work underscores the importance of SLO in Strep A virulence while highlighting the complex nature of Strep A pathogenesis. This improved insight into host-pathogen interactions will enable a better understanding of host immune evasion mechanisms and inform streptococcal vaccine development programs.