Antibiofilm potential of lactobionic acid against Salmonella Typhimurium

Abstract

This study aimed to explore the antibiofilm activity and possible mechanism of lactobionic acid (LBA) against Salmonella enterica subsp. enterica serovar Typhimurium (S. Typhimurium). The minimum inhibitory concentration (MIC) of LBA against S. Typhimurium was 8 mg/mL. At sub-inhibitory concentrations (SICs), LBA inhibited the biofilm formation of S. Typhimurium on glass surface, as evidenced by the results of microscope observations. Crystal violet staining assay and cell enumeration assay revealed that LBA was also effective in inhibiting the biofilm formation on stainless steel surface. Moreover, LBA repressed the swimming and swarming motility of S. Typhimurium and also reduced the production of extracellular polysaccharide and protein during biofilm formation. Reverse transcription quantitative real-time polymerase chain reaction (RT-qPCR) analysis revealed that LBA down-regulated the expression of genes involved in S. Typhimurium biofilm formation. These data suggested that LBA exerted an inhibitory effect on S. Typhimurium biofilm formation through interfering with cell motility, extracellular polysaccharide and protein production as well as expression of biofilm-related genes. Additionally, LBA at 4MIC and 8MIC had the efficacy to inactivate S. Typhimurium biofilms formed on stainless steel and chicken meat.