title: Assessment of the activity of RND-type multidrug efflux pumps in Pseudomonas aeruginosa using tetraphenylphosphonium ions.
abstract: Multidrug resistance (MDR) pumps are one of the major causes of antibiotic resistance in Pseudomonas aeruginosa. Thus, fast and reliable methods are needed to assay the efficiency of MDR pumps in these bacteria. In this study, it was demonstrated that a membrane voltage (Deltapsi) indicator tetraphenylphosphonium (TPP(+)) in combination with the efflux pump inhibitor phenylalanyl-arginyl-beta-naphthylamide can be used to monitor the activity of resistance-nodulation-cell division (RND)-type efflux pumps in P. aeruginosa. By controlling the outer membrane permeability and Deltapsi, electrochemical measurements of RND pump activity in real time were performed. It was demonstrated that the composition of the medium, the presence of nutrients and the level of aeration affect the efficiency of the TPP(+)-extruding activity of P. aeruginosa, urging the standardisation of experimental conditions to obtain quantitative and comparative results.
authors.affiliation: Department of Biochemistry and Biophysics, Vilnius University, Lithuania. r.daugelavicius@gmf.vdu.lt
authors.forename: Rimantas
authors.initials: R
authors.lastname: Daugelavicius
authors.forename: Andrius
authors.initials: A
authors.lastname: Buivydas
authors.forename: Ana
authors.initials: A
authors.lastname: Sencilo
authors.forename: Dennis H
authors.initials: DH
authors.lastname: Bamford
mesh_terms: D018528:ATP-Binding Cassette Transporters / Q000378:metabolism*; D001426:Bacterial Proteins / Q000378:metabolism*; D002463:Cell Membrane Permeability / Q000187:drug effects; D003470:Culture Media / Q000737:chemistry; D004151:Dipeptides / Q000378:metabolism; D024901:Drug Resistance, Multiple, Bacterial; D004791:Enzyme Inhibitors / Q000378:metabolism; D006801:Humans; D007477:Ions / Q000378:metabolism*; D008564:Membrane Potentials; D009861:Onium Compounds / Q000378:metabolism*; D009943:Organophosphorus Compounds / Q000378:metabolism*; D011550:Pseudomonas aeruginosa / Q000187:drug effects* / Q000378:metabolism
chemical_list: D018528:ATP-Binding Cassette Transporters; D001426:Bacterial Proteins; D003470:Culture Media; D004151:Dipeptides; D004791:Enzyme Inhibitors; D007477:Ions; D009861:Onium Compounds; D009943:Organophosphorus Compounds; C474925:phenylalanylarginine-naphthylamide; C013289:tetraphenylphosphonium