Bloodstream Yeast Species and In Vitro Antifungal Susceptibility Profiles

BACKGROUND/AIMS Bloodstream yeast infections have increased substantially in many countries worldwide and pose a significant threat. This study investigated the distribution of bloodstream yeast species and determined the antifungal susceptibility profiles. MATERIAL and METHODS A total of 52 yeast isolates were collected from the microbiology laboratory of the University Hospital. These isolates were collected from blood specimens that were submitted for culture test from in-patients, who have high body temperature. Of these isolates, 41 isolates of Candida spp. were identified using Brilliance (TM) Candida Agar, germ tube test, and tested for the chitin synthase 1 ( CHS1) gene. Selected isolates were tested against seven antifungal agents by disk diffusion method, and the minimum inhibitory concentration (MIC) was determined by MIC Test Strips for the mutidrug resistant isolates. The study protocol was reviewed and approved by the Institutional Review Board. RESULTS Candida albicans accounted for 52%, C. glabrata (26.9%), C. krusei (9.6%), and C. tropicalis (6.7%). The newly emerging yeasts included C. parapsilosis, C. zeylanoides, C. apicola, Blastoschizomyces capitatus, Cryptococcus neoformans, Kluyveromyces, and Rhodotorula mucilaginosa. Most Candida species were highly susceptible to amphotericin B and caspofungin. Between 38 and 69% of C. albicans, isolates were resistant to the azoles. The non- Candida albicans (NCA) species showed different susceptibility patterns. Anidulafungin had the lowest MIC90 at 0.047 mu g/mL. The CHS1 gene was detected in C. albicans and in three NCA spp. CONCLUSION Identifying the isolated species and determining their susceptibility pattern are essential to alert physicians to infections with rare and uncommon fungal species to optimize the antifungal therapy.