Figure 2.

Interconnected pathways contributing to central carbon metabolism, LPS, and EPS synthesis in P. aeruginosa and S. aureus. P. aeruginosa and S. aureus have distinct carbon preferences and metabolic pathways that contribute to pathogenesis. Carbon catabolite repression (CCR) ensures that P. aeruginosa consumes succinate until it is depleted whereas S. aureus preferentially consumes glucose. The continuous consumption of succinate by P. aeruginosa generates endogenous bacterial reactive oxygen species (ROS) via increased aerobic respiration. P. aeruginosa adapts by bypassing OXPHOS and upregulating the glyoxylate shunt and the Entner-Doudoroff pathways, resulting in increased extracellular polysaccharide (EPS) synthesis. S. aureus, meanwhile, is highly dependent on glycolysis and fermentative metabolism for survival during infection. When glycolysis is interrupted, as it is in itaconate-rich environments, carbon is shunted into EPS synthesis.