The in vivo effect of mutations in the conserved region of MdsAa in the presence of wild-type MdsB and TolC without MdsC.

aThe in vivo effect of each mutation in the conserved region of MdsA was determined by measuring the resistance of the ATCC14028SΔacrABΔmdsABC::Cm5 strain to several substrates. MdsA and its variants were expressed from pMdsAB2, pMdsAB2 MdsA-R135D, pMdsAB2 MdsA-L139D, and pMdsAB2 MdsA-S146D.bAll MIC measurements were done in triplicate. The concentrations of crystal violet and acriflavine used to determine the MICs were 0, 1, 2, 4, 8, 16, and 32 µg/mL. The concentrations of rhodamine 6G and methylene blue used to determine the MICs were 0, 4, 8, 16, 32, 64, 128, and 256 µg/mL.cNone, strain carrying the empty vector pKAN6B instead of an pMdsAB2 variant.