Studies of multidrug efflux pump activity in salmonella enterica using nile red stain and tetraphenylphosphonium and tetraphenylarsonium cations

Abstract

Multidrug resistance (MDR) efflux pumps is the main reason of Salmonella enterica cell resistance to antibiotics. We used spectrofluorimetric method to assay the activity of MDR pumps. The entry of lipophilic stain, such as Nile red (NR), into the cells increases its fluorescence because of the staining on intracellular lipids. We present data on the fluorimetrical assay of accumulation of tetraphenylphosphonium (TPP+) and tetraphenylarsonium (TPAs+) ions in bacteria. Effects of RND-type MDR pump inhibitor phenylalanyl-arginyl-β-naphtylamide were also studied. In this study we demonstrated competition between NR stain and TPP+ or TPAs+ ions