Inhibitory Effects of Lactobionic Acid on Biofilm Formation and Virulence of Staphylococcus aureus

<i>Staphylococcus aureus</i> biofilm is a common bio-contaminant source that leads to food cross-contamination and foodborne disease outbreaks. Hence, there is a need for searching novel antibiofilm agents with potential anti-virulence properties to control <i>S. aureus</i> contamination and infections in food systems. In this study, the antibiofilm effects of lactobionic acid (LBA) against <i>S. aureus</i> and its influence on virulence were explored. The minimum inhibition concentration of LBA on <i>S. aureus</i> was 8 mg/mL. Viable count and crystal violet assays revealed that LBA inhibited and inactivated <i>S. aureus</i> biofilms. Microscopic observations further confirmed the antibiofilm activity of LBA on <i>S. aureus</i> that disrupted the biofilm architecture and inactivated the viable cells in biofilms. Moreover, LBA decreased the release of extracellular DNA (eDNA) and extracellular polysaccharide (EPS) in <i>S. aureus</i> biofilms. LBA suppressed biofilm formation by intervening metabolic activity and reduced virulence secretion by repressing the hemolytic activity of <i>S. aureus</i>. Furthermore, LBA altered the expressions of biofilm- and virulence-related genes in <i>S. aureus</i>, further confirming that LBA suppressed biofilm formation and reduced the virulence secretion of <i>S. aureus</i>. The results suggest that LBA might be useful in preventing and controlling biofilm formation and the virulence of <i>S. aureus</i> to ensure food safety.