title: Quinolone resistance mutations in the GrlB protein of Staphylococcus aureus.
abstract: Two altered GrlB proteins (one with an Asp-432-->Asn alteration and one with an Asn-470-->Asp alteration) of Staphylococcus aureus were purified as fusion proteins to maltose-binding protein. The 50% inhibitory concentrations of levofloxacin were 14 and 3.4 microg/ml against topoisomerase IV containing GrlB proteins with alterations at positions 432 and 470, respectively. These results suggest that the alteration of Asp to Asn at position 432 may be responsible for quinolone resistance.
authors.affiliation: New Product Research Laboratories I, Daiichi Pharmaceutical Co. Ltd., Edogawa-ku, Tokyo 134-8630, Japan. tanakpmj@daiichipharm.co.jp
authors.forename: M
authors.initials: M
authors.lastname: Tanaka
authors.forename: Y
authors.initials: Y
authors.lastname: Onodera
authors.forename: Y
authors.initials: Y
authors.lastname: Uchida
authors.forename: K
authors.initials: K
authors.lastname: Sato
mesh_terms: D000890:Anti-Infective Agents / Q000494:pharmacology*; D027101:DNA Topoisomerase IV; D004250:DNA Topoisomerases, Type II / Q000235:genetics*; D004352:Drug Resistance, Microbial; D024841:Fluoroquinolones; D008826:Microbial Sensitivity Tests; D009675:Novobiocin / Q000494:pharmacology; D017354:Point Mutation; D013211:Staphylococcus aureus / Q000187:drug effects* / Q000235:genetics; D059005:Topoisomerase II Inhibitors
chemical_list: D000890:Anti-Infective Agents; D024841:Fluoroquinolones; D059005:Topoisomerase II Inhibitors; D009675:Novobiocin; D027101:DNA Topoisomerase IV; D004250:DNA Topoisomerases, Type II