MdtG-mediated L-arabinose efflux inhibits Cronobacter sakazakii biofilm formation

Cronobacter sakazakii is a foodborne pathogen that mainly infects infants and the elderly, which can form biofilms that are difficult to remove. D-carbohydrates are common quorum sensing inhibitors during bacterial biofilm formation, while the roles of L- carbohydrates and their corresponding efflux pumps in biofilm formation are less studied in C. sakazakii . In this study, the role and mechanism of multidrug resistance efflux pump MdtG in biofilm formation of C. sakazakii was investigated with gene knockout method. The results showed that MdtG, which was validated as a novel L-arabinose efflux pump, could efflux L-arabinose as an active inhibitor of the quorum-sensing signaling molecule AI-2 and inhibited the level of biofilm formation by downregulating the peptidoglycan content, exopolysaccharide secretion, membrane permeability, motility, self-aggregation capacity, and cell length of C. sakazakii . This study revealed the effect and molecular mechanism of the multidrug resistance efflux pump MdtG on biofilm formation in C. sakazakii and provided a potential novel quorum sensing inhibitor, L-arabinose, on the control of C. sakazakii biofilm. • The multidrug resistance efflux pump MdtG was validated as a novel L-arabinose efflux pump in C. sakazakii. • L-arabinose was confirmed as a novel quorum sensing inhibitor in C. sakazakii. • L-arabinose can inhibit the active of AI-2 and the biofilm formation of C. sakazakii.