Pathogens generate molecules, or virulence factors, that enable them to colonize host tissues through several mechanisms, including adhesion to host tissues, or superior invasive capability. Some allow the pathogen to evade the host's immune system. Many of these molecules are proteins that are exported to the cell's surface or secreted. Curiously, GAPDH, which is a glycolytic enzyme, is also a virulence factor that has been shown to contribute to Streptococcus pyogenes pathogenicity by each of these mechanisms.
Seidler KA, Seidler NW. Role of Extracellular GAPDH in Streptococcus Pyogenes Virulence. Missouri Medicine. 2013; 110(3).