title: Relatedness of medically important strains of Saccharomyces cerevisiae as revealed by phylogenetics and metabolomics.
abstract: Ten medically important Saccharomyces strains, comprising six clinical isolates of Saccharomyces cerevisiae and four probiotic strains of Saccharomyces boulardii, were characterized at the genetic and metabolic level and compared with non-medical, commercial yeast strains used in baking and wine-making. Strains were compared by genetic fingerprinting using amplified fragment length polymorphism (AFLP) analysis, by ribosomal DNA ITS1 sequencing and by metabolic footprinting using both direct injection mass spectrometry (DIMS) and gas chromatography-time of flight-mass spectrometry (GC-ToF-MS). Overall, the clinical isolates fell into different groupings when compared with the non-medical strains, with good but not perfect correlation amongst strains at both the genetic and metabolic levels. Probiotic strains of S. boulardii that are used therapeutically to treat human gastro-intestinal tract disorders showed tight clustering both genetically and metabolically. Metabolomics was found to be of value both as a taxonomic tool and as a means to investigate anomalous links between genotype and phenotype. Key discriminatory metabolites were identified when comparing the three main groups of clinical, probiotic and non-medical strains and included molecules such as trehalose, myo-inositol, lactic acid, fumaric acid and glycerol 3-phosphate. This study confirmed the link between a subset of clinical isolates and baking or probiotic strains but also highlighted that in general the clinical strains were more diverse at both the genomic and metabolic levels.
authors.affiliation: National Collection of Yeast Cultures, Institute of Food Research, Norwich Research Park, Colney, Norwich NR4 7UA, UK. donald.mackenzie@bbsrc.ac.uk
authors.forename: Donald A
authors.initials: DA
authors.lastname: MacKenzie
authors.forename: Marianne
authors.initials: M
authors.lastname: Defernez
authors.forename: Warwick B
authors.initials: WB
authors.lastname: Dunn
authors.forename: Marie
authors.initials: M
authors.lastname: Brown
authors.forename: Linda J
authors.initials: LJ
authors.lastname: Fuller
authors.forename: Santiago R M Seco
authors.initials: SR
authors.lastname: de Herrera
authors.forename: Andreas
authors.initials: A
authors.lastname: Günther
authors.forename: Steve A
authors.initials: SA
authors.lastname: James
authors.forename: John
authors.initials: J
authors.lastname: Eagles
authors.forename: Mark
authors.initials: M
authors.lastname: Philo
authors.forename: Royston
authors.initials: R
authors.lastname: Goodacre
authors.forename: Ian N
authors.initials: IN
authors.lastname: Roberts
mesh_terms: D004271:DNA, Fungal / Q000032:analysis*; D021903:DNA, Ribosomal Spacer / Q000032:analysis; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods; D053858:Metabolic Networks and Pathways; D016533:Mycological Typing Techniques; D010802:Phylogeny; D019936:Probiotics; D019105:Random Amplified Polymorphic DNA Technique; D012441:Saccharomyces cerevisiae / Q000145:classification / Q000235:genetics
chemical_list: D004271:DNA, Fungal; D021903:DNA, Ribosomal Spacer