title: Identification and Antifungal Susceptibility Testing ofCandidaSpecies: A Comparison of Vitek-2 System with Conventional and Molecular Methods.
abstract: BACKGROUND
  Candida infection is a major cause of morbidity and mortality in immunocompromised patients; an accurate and early identification is a prerequisite need to be taken as an effective measure for the management of patients. The purpose of this study was to compare the conventional identification of Candida species with identification by Vitek-2 system and the antifungal susceptibility testing (AST) by broth microdilution method with Vitek-2 AST system.
  
  
  METHODS
  A total of 172Candidaisolates were subjected for identification by the conventional methods, Vitek-2 system, restriction fragment length polymorphism, and random amplified polymorphic DNA analysis. AST was carried out as per the Clinical and Laboratory Standards Institute M27-A3 document and by Vitek-2 system.
  
  
  RESULTS
  Candida albicans(82.51%) was the most commonCandidaspecies followed byCandida tropicalis(6.29%),Candida krusei(4.89%),Candida parapsilosis(3.49%), andCandida glabrata(2.79%). With Vitek-2 system, of the 172 isolates, 155Candidaisolates were correctly identified, 13 were misidentified, and four were with low discrimination. Whereas with conventional methods, 171 Candida isolates were correctly identified and only a single isolate ofC. albicanswas misidentified asC. tropicalis. The average measurement of agreement between the Vitek-2 system and conventional methods was >94%. Most of the isolates were susceptible to fluconazole (88.95%) and amphotericin B (97.67%). The measurement of agreement between the methods of AST was >94% for fluconazole and >99% for amphotericin B, which was statistically significant (P< 0.01).
  
  
  CONCLUSIONS
  The study confirmed the importance and reliability of conventional and molecular methods, and the acceptable agreements suggest Vitek-2 system an alternative method for speciation and sensitivity testing of Candida species infections.
authors.affiliation: Department of Microbiology, Lady Hardinge Medical College and Associated Hospitals, New Delhi, India.
authors.forename: Ravinder
authors.initials: R
authors.lastname: Kaur
authors.affiliation: Department of Microbiology, Maulana Azad Medical College and Associated Lok Nayak Hospitals, New Delhi, India.
authors.forename: Megh Singh
authors.initials: MS
authors.lastname: Dhakad
authors.affiliation: Department of Microbiology, Maulana Azad Medical College and Associated Lok Nayak Hospitals, New Delhi, India.
authors.forename: Ritu
authors.initials: R
authors.lastname: Goyal
authors.affiliation: King Fahd Medical Research Center, King Abdulaziz University, Jeddah 21589, Saudi Arabia.
authors.forename: Absarul
authors.initials: A
authors.lastname: Haque
authors.affiliation: Special Centre for Molecular Medicine, Jawaharlal Nehru University, New Delhi, India.
authors.forename: Gauranga
authors.initials: G
authors.lastname: Mukhopadhyay
keywords: Antifungal agents; Candida species; antifungal resistance; fungi; mycology; opportunistic infections