title: Inhibitory effect of chromogenic culture media on the growth of Rhodotorula: relevance to the diagnosis of Rhodotorula spp. infections.
abstract: With the increasing incidence and diverse etiologies of fungal infections, chromogenic yeast culture media are increasingly used for routine diagnosis. Rhodotorula species, which are characterized by the production of carotenoid pigments, are considered as emerging opportunistic pathogens. We recently diagnosed two fungemia due to Rhodotorula spp. and noticed that in both cases, the yeast failed to grow in subculture on the chromogenic yeast culture medium. This study was thus undertaken to investigate more thoroughly the ability (or inability) of Rhodotorula species to grow on different commercially available chromogenic media for yeast. Eighteen Rhodotorula spp. were checked for their ability to grow on four chromogenic yeast culture media: CHROMagar Candida (BD), Candi 4 Select (Biorad), Brilliance Candida (Oxoid), and Candida ID 2 (BioMerieux). All the Rhodotorula spp. strains grew on Brilliance and Candida ID 2, while only six isolates grew on Candi 4, and seven on CHROMagar. Two chromogenic yeast culture media showed a significant inhibitory effect on the growth of Rhodotorula species. As all Rhodotorula species are resistant to echinocandins and fluconazole, it is essential to isolate and identify these yeast quickly to initiate appropriate amphotericin B antifungal treatment as early as possible. The choice of media for routine use should take into account the ability of different media to allow all emerging fungal pathogens to grow.
authors.affiliation: CNRS 6249/UMR Chrono-environnement, Univ Franche Comte, Besançon, France; Parasitology-Mycology Department, University Hospital of Besançon, Besançon, France; Clinical Investigation Center (Inserm CIT 808), University Hospital of Besançon, Besançon, France.
authors.forename: Anne-Pauline
authors.initials: AP
authors.lastname: Bellanger
authors.forename: Frédéric
authors.initials: F
authors.lastname: Grenouillet
authors.forename: Nadine
authors.initials: N
authors.lastname: François
authors.forename: Florence
authors.initials: F
authors.lastname: Skana
authors.forename: Laurence
authors.initials: L
authors.lastname: Millon
mesh_terms: D002863:Chromogenic Compounds / Q000494:pharmacology*; D003470:Culture Media; D006801:Humans; D009181:Mycoses / Q000175:diagnosis*; D012248:Rhodotorula / Q000187:drug effects / Q000254:growth & development*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D002863:Chromogenic Compounds; D003470:Culture Media
keywords: MALDI TOF; Rhodotorula; chromogenic culture media; inhibitory effect