title: Candida albicans identification: comparison among nine phenotypic systems and a multiplex PCR.
abstract: BACKGROUND
  Candida albicans is the most common fungal pathogen isolated from clinical samples and is also the most common yeast species carried as a commensal by healthy individuals although some non-C. albicans species account for an important number of infections.
  
  
  OBJECTIVE
  To compare nine phenotypic systems for C. albicans identification [API 20C AUX; RapID Yeast Identification panel (RYIP); Vitek2 ID-YST system; chromogenic media, CHRO-Magar, Oxoid Chromogenic Candida Agar (OCCA), Candida ID2, Candida Identification Agar, CandiSelect 4, and Chromalbicans Agar] with multiplex PCR.
  
  
  METHODS
  A collection of 390 yeast strains was obtained by routine isolation from oral and vaginal swabs. All of the yeasts isolated were tested for germ tube formation, and then submitted to a multiplex PCR protocol tested in previous studies, and to nine phenotypical commercial methods, together with the reference ATCC strains. Comparison was limited to the ability of the tests to identify C. albicans.
  
  
  RESULTS
  253 isolates were provisionally identified as C. albicans by germ tube, and their identities were further confirmed with the multiplex PCR. Sensitivity of phenotypical systems ranged from 81.9% (Vitek2) to 87.7% (Candida ID2 e CHROMagar). For specificity, the highest value was 96.8% for Candida ID2, and the lowest value (75.1%) was for Chromalbicans Agar.
  
  
  CONCLUSIONS
  Although with differences in discriminatory power, the methods tested showed overall acceptable levels of sensitivity and specificity respect to the multiplex PCR; therefore, all could be useful for C. albicans identification where molecular differentiation is not available.
authors.affiliation: Department of Studies of Institutions and Territorial Systems, University of Naples Parthenope, Italy. liguori@uniparthenope.it
authors.forename: G
authors.initials: G
authors.lastname: Liguori
authors.forename: V
authors.initials: V
authors.lastname: Di Onofrio
authors.forename: F
authors.initials: F
authors.lastname: Gallé
authors.forename: A
authors.initials: A
authors.lastname: Lucariello
authors.forename: L
authors.initials: L
authors.lastname: Albano
authors.forename: M R
authors.initials: MR
authors.lastname: Catania
authors.forename: M
authors.initials: M
authors.lastname: Guida
mesh_terms: D002176:Candida albicans / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification; D002177:Candidiasis / Q000382:microbiology*; D005260:Female; D006801:Humans; D007558:Italy; D009055:Mouth / Q000382:microbiology; D016533:Mycological Typing Techniques / Q000379:methods*; D010641:Phenotype; D016133:Polymerase Chain Reaction / Q000379:methods; D012680:Sensitivity and Specificity; D014626:Vaginal Smears