A PTS EII mutant library in Group A Streptococcus identifies a promiscuous man‐family PTS transporter influencing SLS‐mediated hemolysis

The Group A Streptococcus (GAS, Streptococcus pyogenes) is a Gram‐positive human pathogen that must adapt to unique host environments in order to survive. Links between sugar metabolism and virulence have been demonstrated in GAS, where mutants in the phosphoenolpyruvate‐dependent phosphotransferase system (PTS) exhibited Streptolysin S (SLS)‐mediated hemolysis during exponential growth. This early onset hemolysis correlated with an increased lesion size and severity in a murine soft tissue infection model when compared with parental M1T1 MGAS5005. To identify the PTS components responsible for this phenotype, we insertionally inactivated the 14 annotated PTS EIIC‐encoding genes in the GAS MGAS5005 genome and subjected this library to metabolic and hemolysis assays to functionally characterize each EIIC. It was found that a few EIIs had a very limited influence on PTS sugar metabolism, whereas others were fairly promiscuous. The mannose‐specific EII locus, encoded by manLMN, was expressed as a mannose‐inducible operon that exhibited the most influence on PTS sugar metabolism, including mannose. Importantly, components of the mannose‐specific EII also acted to prevent the early onset of SLS‐mediated hemolysis. Interestingly, these roles were not identical in two different M1T1 GAS strains, highlighting the possible versatility of the PTS to adapt to strain‐specific needs.