title: Electric transmembrane potential mutation and resistance to the cationic and amphiphilic antitumoral drugs derived from pyridocarbazole, 2-N-methylellipticinium and 2-N-methyl-9-hydroxyellipticinium, in Streptococcus pneumoniae.
abstract: delta psi-reduced amiA mutants of Streptococcus pneumoniae were shown to be resistant to the positively charged antitumoral drugs 2-N-methylellipticinium (NME) and 2-N-methyl-9-hydroxyellipticinium (NMHE). Conversely, mutants selected for their resistance to NMHE were mapped within the amiA locus and exhibited the pleiotropic AmiA- phenotype. This shows that delta psi is a critical parameter in determining resistance to these drugs in S. pneumoniae and suggests that they are accumulated within this bacterium in response to delta psi. As a consequence NME and NMHE appear to be valuable tools for selecting delta psi-reduced mutants in S. pneumoniae.
mesh_terms: D000470:Alkaloids / Q000494:pharmacology*; D055598:Chemical Phenomena; D002621:Chemistry; D002874:Chromosome Mapping; D004352:Drug Resistance, Microbial; D004611:Ellipticines / Q000494:pharmacology*; D008564:Membrane Potentials; D009154:Mutation; D013296:Streptococcus pneumoniae / Q000187:drug effects* / Q000235:genetics
chemical_list: D000470:Alkaloids; D004611:Ellipticines; C027767:elliptinium; C027211:2-methylellipticinium