title: 4-Quinolone resistance mutations in the DNA gyrase of Escherichia coli clinical isolates identified by using the polymerase chain reaction.
abstract: Seven nalidixic acid-resistant clinical isolates of Escherichia coli were shown to carry resistance mutations in their gyrase A proteins. Six had serine-83 to leucine or tryptophan changes; the seventh had an aspartate-87 to valine substitution. The frequent occurrence of a mutation at serine-83 implies a key role for this residue in quinolone action.
authors.affiliation: Department of Cellular and Molecular Sciences, St. George's Hospital Medical School, London, United Kingdom.
authors.forename: M
authors.initials: M
authors.lastname: Oram
authors.forename: L M
authors.initials: LM
authors.lastname: Fisher
mesh_terms: D000595:Amino Acid Sequence; D000890:Anti-Infective Agents / Q000494:pharmacology*; D001483:Base Sequence; D004250:DNA Topoisomerases, Type II / Q000235:genetics / Q000378:metabolism*; D004269:DNA, Bacterial / Q000032:analysis / Q000378:metabolism; D004352:Drug Resistance, Microbial; D004926:Escherichia coli / Q000187:drug effects* / Q000201:enzymology / Q000235:genetics; D006801:Humans; D008969:Molecular Sequence Data; D008970:Molecular Weight; D009268:Nalidixic Acid / Q000494:pharmacology; D016133:Polymerase Chain Reaction; D013462:Sulfur Radioisotopes
chemical_list: D000890:Anti-Infective Agents; D004269:DNA, Bacterial; D013462:Sulfur Radioisotopes; D009268:Nalidixic Acid; D004250:DNA Topoisomerases, Type II