Disruption of the rpfB Gene Impairs Growth and Virulence in Cronobacter sakazakii through Downregulation of the Shikimate Pathway

The rpfB gene, encoding long-chain acyl-CoA synthetase, plays an essential role in the fatty acid metabolism of Cronobacter sakazakii, a pathogenic bacterium known to cause neonatal infections. Here, we investigate the functional consequences of rpfB gene knockout and its effect on bacterial growth and virulence. Our findings demonstrate that rpfB deletion leads to significantly reduced bacterial growth and virulence in a murine infection model. Proteomic analysis revealed that the disruption of rpfB markedly downregulates key enzymes in the shikimate pathway, including aroA and aroK, which are essential for the biosynthesis of aromatic amino acids. Supplementation with aromatic amino acids restored the growth defect, highlighting the critical link between fatty acid metabolism and the shikimate pathway. These results uncover a novel regulatory role for rpfB in coordinating metabolic networks that control bacterial growth and virulence. This study provides a new understanding of the metabolic mechanisms underlying C. sakazakii pathogenicity and identifies possible metabolic targets for antimicrobial development.