title: Apparent involvement of a multidrug transporter in the fluoroquinolone resistance of Streptococcus pneumoniae.
abstract: A Streptococcus pneumoniae strain selected for resistance to ethidium bromide demonstrated enhanced energy-dependent efflux of this toxic dye. Both the ethidium resistance and the ethidium efflux could be inhibited by the plant alkaloid reserpine. The ethidium-selected cells demonstrated cross-resistance to the fluoroquinolones norfloxacin and ciprofloxacin; this resistance could also be completely reversed by reserpine. Furthermore, reserpine potentiated the susceptibility of wild-type S. pneumoniae to fluoroquinolones and ethidium. The most plausible explanation for these results is that S. pneumoniae, like some other gram-positive bacteria, expresses a reserpine-sensitive multidrug transporter, which may play an important role in both intrinsic and acquired resistances of this pathogen to fluoroquinolone therapy.
authors.affiliation: Department of Medicinal Chemistry and Pharmacognosy and Center for Pharmaceutical Biotechnology, University of Illinois, Chicago 60607, USA.
authors.forename: N N
authors.initials: NN
authors.lastname: Baranova
authors.forename: A A
authors.initials: AA
authors.lastname: Neyfakh
mesh_terms: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000378:metabolism*; D000890:Anti-Infective Agents / Q000493:pharmacokinetics / Q000494:pharmacology*; D004352:Drug Resistance, Microbial; D018432:Drug Resistance, Multiple / Q000502:physiology*; D004996:Ethidium / Q000493:pharmacokinetics / Q000494:pharmacology; D005456:Fluorescent Dyes / Q000493:pharmacokinetics / Q000494:pharmacology; D024841:Fluoroquinolones; D013296:Streptococcus pneumoniae / Q000187:drug effects* / Q000378:metabolism*
chemical_list: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D000890:Anti-Infective Agents; D005456:Fluorescent Dyes; D024841:Fluoroquinolones; D004996:Ethidium