title: Mutator plasmid in a nalidixic acid-resistant strain of Shigella dysenteriae type 1.
abstract: A clinical isolate of Shigella dysenteriae from Kashmir, resistant to seven antibacterial agents including nalidixic acid, carried four plasmids, only one of which was transferable by conjugation. This plasmid, designated pYD1, conferred trimethoprim resistance and increased the frequency of mutation to nalidixic acid resistance in recipient strains. Thus, although nalidixic acid resistance was not carried on a transferable plasmid, the presence of pYD1 increased the frequency at which the strain mutated to nalidixic acid resistance.
authors.affiliation: Department of Pharmaceutics, School of Pharmacy, University of London, UK.
authors.forename: J E
authors.initials: JE
authors.lastname: Ambler
authors.forename: Y J
authors.initials: YJ
authors.lastname: Drabu
authors.forename: P H
authors.initials: PH
authors.lastname: Blakemore
authors.forename: R J
authors.initials: RJ
authors.lastname: Pinney
mesh_terms: D003227:Conjugation, Genetic; D004260:DNA Repair; D004352:Drug Resistance, Microbial; D004926:Escherichia coli / Q000235:genetics / Q000528:radiation effects; D009154:Mutation; D009268:Nalidixic Acid / Q000494:pharmacology*; D010957:Plasmids; D012762:Shigella dysenteriae / Q000187:drug effects / Q000235:genetics*; D014466:Ultraviolet Rays
chemical_list: D009268:Nalidixic Acid