title: A novel fusidic acid resistance determinant, fusF, in Staphylococcus cohnii.
abstract: OBJECTIVE
  To determine MICs of fusidic acid for and identify genetic determinants of resistance in Staphylococcus cohnii isolates.
  
  
  METHODS
  Susceptibility to fusidic acid was determined by the standard agar dilution method in 24 S. cohnii subsp. urealyticus clinical isolates, 7 S. cohnii subsp. cohnii clinical isolates and 2 reference strains. Sequencing of a novel resistance determinant, fusF, and its flanking regions was performed by long and accurate PCR and inverse PCR. To evaluate the function of fusF, the MIC of fusidic acid was determined for recombinant Staphylococcus aureus carrying a plasmid expressing fusF.
  
  
  RESULTS
  A total of 25 S. cohnii subsp. urealyticus (24 clinical isolates and 1 reference strain) and 2 S. cohnii subsp. cohnii displayed low-level resistance to fusidic acid (MICs 2-16 mg/L). Sequencing of a 4259 bp fragment from S. cohnii subsp. urealyticus ATCC 49330 revealed a novel resistance gene, designated fusF, which displayed 70.5% nucleotide and 67.3% amino acid identity to fusD. Expression of fusF in S. aureus confers resistance to fusidic acid.
  
  
  CONCLUSIONS
  A novel FusB-family gene, fusF, was identified as a major resistance determinant in S. cohnii clinical isolates resistant to fusidic acid.
authors.affiliation: Department of Clinical Laboratory Sciences and Medical Biotechnology, National Taiwan University College of Medicine, Taipei, Taiwan.
authors.forename: Hsiao-Jan
authors.initials: HJ
authors.lastname: Chen
authors.affiliation: Department of Clinical Laboratory Sciences and Medical Biotechnology, National Taiwan University College of Medicine, Taipei, Taiwan.
authors.forename: Wei-Chun
authors.initials: WC
authors.lastname: Hung
authors.affiliation: Department of Clinical Laboratory Sciences and Medical Biotechnology, National Taiwan University College of Medicine, Taipei, Taiwan.
authors.forename: Yu-Tzu
authors.initials: YT
authors.lastname: Lin
authors.affiliation: Center for Optoelectronic Medicine, National Taiwan University College of Medicine, Taipei, Taiwan Division of Neurosurgery, Department of Surgery, National Taiwan University Hospital, Taipei, Taiwan.
authors.forename: Jui-Chang
authors.initials: JC
authors.lastname: Tsai
authors.affiliation: Department of Clinical Laboratory Sciences and Medical Biotechnology, National Taiwan University College of Medicine, Taipei, Taiwan Department of Laboratory Medicine, National Taiwan University Hospital, Taipei, Taiwan.
authors.forename: Hao-Chieh
authors.initials: HC
authors.lastname: Chiu
authors.affiliation: Department of Laboratory Medicine, National Taiwan University Hospital, Taipei, Taiwan Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan.
authors.forename: Po-Ren
authors.initials: PR
authors.lastname: Hsueh
authors.affiliation: Department of Clinical Laboratory Sciences and Medical Biotechnology, National Taiwan University College of Medicine, Taipei, Taiwan Department of Laboratory Medicine, National Taiwan University Hospital, Taipei, Taiwan ljteng@ntu.edu.tw.
authors.forename: Lee-Jene
authors.initials: LJ
authors.lastname: Teng
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D024881:Drug Resistance, Bacterial / Q000235:genetics; D005672:Fusidic Acid / Q000494:pharmacology*; D023061:Gene Order; D005798:Genes, Bacterial; D006801:Humans; D008826:Microbial Sensitivity Tests; D016366:Open Reading Frames; D017422:Sequence Analysis, DNA; D013210:Staphylococcus / Q000187:drug effects* / Q000235:genetics*; D013211:Staphylococcus aureus / Q000187:drug effects / Q000235:genetics
chemical_list: D000900:Anti-Bacterial Agents; D005672:Fusidic Acid
keywords: FusB family; fusD; staphylococci