title: Effects of fluconazole on the metabolomic profile of Candida albicans.
abstract: BACKGROUND
  Little is known about the effects of fluconazole on the metabolism of Candida albicans. We performed LC/MS-based metabolomic profiling of the response of C. albicans cells to increasing doses of fluconazole.
  
  
  METHODS
  C. albicans cells were cultured to mid-logarithmic growth phase in liquid medium and then inoculated in replicate on to nitrocellulose filters under vacuum filtration. Organisms were cultured to mid-logarithmic growth phase and treated with 0-4 mg/L fluconazole. Following metabolic quenching at mid-logarithmic growth phase, intracellular metabolites were extracted and analysed by LC/MS. Changes in pool sizes of individual metabolites were verified by Student's t-test, adjusted for multiple hypothesis testing by Benjamini-Hochberg correction. Distribution of metabolites was analysed by the Kyoto Encyclopedia of Genes and Genomes metabolic pathways database.
  
  
  RESULTS
  We reproducibly detected 64 metabolites whose identities were confirmed by comparison against a pure standard and a library of accurate mass-retention time pairs. These 64 metabolites were broadly representative of eukaryotic central metabolic pathways. Among them 12 had their mean abundance significantly altered in response to increasing fluconazole concentrations. Pool sizes of four intermediates of central carbon metabolism (α-ketoglutarate, glucose-6-phosphate, phenylpyruvate and ribose-5-phosphate) and mevalonate were increased by 0.5-1.5-fold (P ≤ 0.05). Five amino acids (glycine, proline, tryptophan, aminoisobutanoate and asparagine) and guanine were decreased by 0.5-0.75-fold (P ≤ 0.05).
  
  
  CONCLUSIONS
  Fluconazole treatment of C. albicans resulted in increased central carbon and decreased amino acid synthesis intermediates, suggesting a rerouting of metabolic pathways. The function of these metabolomic changes remains to be elucidated; however, they may represent previously unrecognized mechanisms of metabolic injury induced by fluconazole against C. albicans.
authors.affiliation: Transplantation-Oncology Infectious Diseases Program, Division of Infectious Diseases, Department of Medicine, Weill Cornell Medical Center of Cornell University, New York, NY, USA.
authors.forename: Aspasia
authors.initials: A
authors.lastname: Katragkou
authors.affiliation: Department of Medicine, Weill Cornell Medical College, New York, NY, USA.
authors.forename: Elizabeth L
authors.initials: EL
authors.lastname: Alexander
authors.affiliation: Department of Molecular Microbiology and Immunology, Keck School of Medicine, University of Southern California, Zilkha Neurogenetic Institute, 1501 San Pablo Street, Los Angeles, CA 90033, USA.
authors.forename: Hyungjin
authors.initials: H
authors.lastname: Eoh
authors.affiliation: Department of Life Sciences, Faculty of Science and Technology, University of Westminster, London W1W 6UV, UK.
authors.forename: Saki K
authors.initials: SK
authors.lastname: Raheem
authors.affiliation: Infectious Disease Unit, 3rd Department of Pediatrics, Faculty of Medicine, Aristotle University School of Health Sciences, Hippokration Hospital, Thessaloniki, Greece.
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Roilides
authors.affiliation: Transplantation-Oncology Infectious Diseases Program, Division of Infectious Diseases, Department of Medicine, Weill Cornell Medical Center of Cornell University, New York, NY, USA Departments of Pediatrics, Microbiology and Immunology, Weill Cornell Medical College of Cornell University, New York, NY, USA thw2003@med.cornell.edu.
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Walsh
mesh_terms: D000596:Amino Acids / Q000378:metabolism; D000935:Antifungal Agents / Q000378:metabolism*; D002176:Candida albicans / Q000187:drug effects* / Q000378:metabolism*; D002244:Carbon / Q000378:metabolism; D002853:Chromatography, Liquid; D015725:Fluconazole / Q000378:metabolism*; D013058:Mass Spectrometry; D053858:Metabolic Networks and Pathways / Q000187:drug effects; D055442:Metabolome / Q000187:drug effects*
chemical_list: D000596:Amino Acids; D000935:Antifungal Agents; D002244:Carbon; D015725:Fluconazole