Characterization and Affecting Factors’ Analysis of Biofilm Formation by <i>Cronobacter sakazakii</i> on Different Food Contact Surfaces

<i>Cronobacter sakazakii</i> is a major pathogen that contaminates infant milk powder, which usually attaches to abiotic surfaces in the form of biofilms and causes diseases. However, few in-depth studies have been conducted on the properties of biofilms formed on different abiotic surfaces. Therefore, this study explored the characteristics of biofilm formation by <i>C. sakazakii</i> on commonly used food contact surfaces, including stainless steel (SS), glass (GS), poly(phenylene sulfone) resin (PPSU), and soft silicone (SSI), with a focus on the biofilm formation ability and the biofilms' functional, structural, and compositional properties. Correlation analysis was used to confirm the leading factors affecting <i>C. sakazakii</i> biofilm formation, including surface hardness and stiffness, cell length, and extracellular nucleic acid content. Finally, proteomic analysis revealed menaquinone biosynthesis, amino acid metabolism, SOS response, and transport systems as being crucial for <i>C. sakazakii</i> biofilm formation. This study provides valuable insights for a deeper understanding of the bacterium's biofilm formation.