title: Differentiation between Candida albicans and Candida dubliniensis using hypertonic Sabouraud broth and tobacco agar.
abstract: BACKGROUND
  Opportunistic fungal infections in immunocompromised hosts are caused by Candida species, and the majority of such infections are due to Candida albicans. However, the emerging pathogen Candida dubliniensis demonstrates several phenotypic characteristics in common with C. albicans, such as production of germ tubes and chlamydospores, calling attention to the development of stable resistance to fluconazole in vitro. The aim of this study was to evaluate the performance of biochemistry identification in the differentiating between C. albicans and C. dubliniensis, by phenotyping of yeast identified as C. albicans.
  
  
  METHODS
  Seventy-nine isolates identified as C. albicans by the API system ID 32C were grown on Sabouraud dextrose agar at 30°C for 24-48h and then inoculated on hypertonic Sabouraud broth and tobacco agar.
  
  
  RESULTS
  Our results showed that 17 (21.5%) isolates were growth-inhibited on hypertonic Sabouraud broth, a phenotypic trait inconsistent with C. albicans in this medium. However, the results observed on tobacco agar showed that only 9 (11.4%) of the growth-inhibited isolates produced characteristic colonies of C. dubliniensis (rough colonies, yellowish-brown with abundant fragments of hyphae and chlamydospores).
  
  
  CONCLUSIONS
  The results suggest that this method is a simple tool for screening C. albicans and non-albicans yeast and for verification of automated identification.
authors.affiliation: Programa de Pós-Graduação em Biologia de Agentes Infecciosos e Parasitários, Instituto de Ciências Biológicas, Universidade Federal do Pará, Belém, PA, Brasil.
authors.forename: Fabíola
authors.initials: F
authors.lastname: Silveira-Gomes
authors.forename: Dayse Nogueira
authors.initials: DN
authors.lastname: Sarmento
authors.forename: Elaine Patrícia Tavares do
authors.initials: EP
authors.lastname: Espírito-Santo
authors.forename: Nádia de Oliveira
authors.initials: Nde O
authors.lastname: Souza
authors.forename: Thifany Mendes
authors.initials: TM
authors.lastname: Pinto
authors.forename: Silvia Helena
authors.initials: SH
authors.lastname: Marques-da-Silva
mesh_terms: D000362:Agar; D002175:Candida / Q000145:classification* / Q000254:growth & development; D002176:Candida albicans / Q000145:classification / Q000254:growth & development; D003470:Culture Media / Q000737:chemistry*; D006801:Humans; D006982:Hypertonic Solutions; D016533:Mycological Typing Techniques / Q000379:methods; D010641:Phenotype; D013045:Species Specificity; D014026:Nicotiana
chemical_list: D003470:Culture Media; D006982:Hypertonic Solutions; D000362:Agar