Biological activity of twenty-three hydantoin derivatives on intrinsic efflux pump system of Salmonella enterica serovar Enteritidis NCTC 13349.

BACKGROUND Hydantoin derivatives have important biochemical and pharmacological properties. In the present study, 23 hydantoin compounds were evaluated for their efflux-modulating effects in Salmonella enterica serovar Enteritidis NCTC 13349 using real-time fluorimetry based on the intracellular accumulation of ethidium bromide (EB), a universal substrate of efflux pumps. MATERIALS AND METHODS Twenty-three hydantoin derivatives were tested for intrinsic efflux pump modulation in S. enterica Enteritidis NCTC 13349 by an automated real-time fluorimetric method that monitors the intracellular accumulation of ethidium bromide. RESULTS None of the compounds were found to have antibacterial activities at concentrations as high as 200 mg/l. Among the hydantoin derivatives tested in our study, only compound SZ7 showed efflux modulating activity on S. enterica Enteritidis NCTC 13349 in the assays that contained or omitted glucose as the singular source of metabolic energy. CONCLUSION SZ7 is shown to be non-toxic and it could be evaluated to cure an efflux mediated MDR Salmonella infection, furthermore a quantitative activity-structural relationship is also planned in order to determine the site of the SZ7 molecule responsible for its efflux pump inhibitory activity.