title: Diversity and antifungal susceptibility of Norwegian Candida glabrata clinical isolates.
abstract: BACKGROUND
  Increasing numbers of immunocompromised patients have resulted in greater incidence of invasive fungal infections with high mortality. Candida albicans infections dominate, but during the last decade, Candida glabrata has become the second highest cause of candidemia in the United States and Northern Europe. Reliable and early diagnosis, together with appropriate choice of antifungal treatment, is needed to combat these challenging infections.
  
  
  OBJECTIVE
  To confirm the identity of 183 Candida glabrata isolates from different human body sites using matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) and VITEK(®)2, and to analyze isolate protein profiles and antifungal susceptibility. The minimum inhibitory concentration (MIC) of seven antifungal drugs was determined for the isolates to elucidate susceptibility.
  
  
  METHODS
  A total of 183 C. glabrata isolates obtained between 2002 and 2012 from Norwegian health-care units were analyzed. For species verification and differentiation, biochemical characterization (VITEK(®)2) and mass spectrometry (MALDI-TOF) were used. MIC determination for seven antifungal drugs was undertaken using E-tests(®).
  
  
  RESULTS
  Using VITEK(®)2, 92.9% of isolates were identified as C. glabrata, while all isolates (100%) were identified as C. glabrata using MALDI-TOF. Variation in protein spectra occurred for all identified C. glabrata isolates. The majority of isolates had low MICs to amphotericin B (≤1 mg/L for 99.5%) and anidulafungin (≤0.06 mg/L for 98.9%). For fluconazole, 18% of isolates had MICs >32 mg/L and 82% had MICs in the range ≥0.016 mg/L to ≤32 mg/L.
  
  
  CONCLUSIONS
  Protein profiles and antifungal susceptibility characteristics of the C. glabrata isolates were diverse. Clustering of protein profiles indicated that many azole resistant isolates were closely related. In most cases, isolates had highest susceptibility to amphotericin B and anidulafungin. The results confirmed previous observations of high MICs to fluconazole and flucytosine. MALDI-TOF was more definitive than VITEK(®)2 for C. glabrata identification.
authors: Institute of Clinical Odontology, University of Tromsø, Tromsø, Norway.|Department of Oral Biology (DOB), Faculty of Dentistry, University of Oslo, Oslo, Norway; andersen.karimette@gmail.com.
authors: Kari-Mette
authors: KM
authors: Andersen
authors: Department of Oral Biology (DOB), Faculty of Dentistry, University of Oslo, Oslo, Norway.
authors: Anne Karin
authors: AK
authors: Kristoffersen
authors: Department of Microbiology, Oslo University Hospital (OUS), Rikshospitalet, University of Oslo, Oslo, Norway.
authors: André
authors: A
authors: Ingebretsen
authors: Department of Oral Biology (DOB), Faculty of Dentistry, University of Oslo, Oslo, Norway.
authors: Katharina Johnsen
authors: KJ
authors: Vikholt
authors: Institute of Clinical Odontology, University of Tromsø, Tromsø, Norway.
authors: Ulf Thore
authors: UT
authors: Örtengren
authors: Department of Oral Biology (DOB), Faculty of Dentistry, University of Oslo, Oslo, Norway.
authors: Ingar
authors: I
authors: Olsen
authors: Department of Oral Biology (DOB), Faculty of Dentistry, University of Oslo, Oslo, Norway.
authors: Morten
authors: M
authors: Enersen
authors: Department of Microbiology, Oslo University Hospital (OUS), Rikshospitalet, University of Oslo, Oslo, Norway.
authors: Peter
authors: P
authors: Gaustad
keywords: C. glabrata; MALDI-TOF; MICs; biochemical; identification