Identification and antifungal susceptibility patterns of Candida species isolated from blood cultures

Abstract

Background and Objectives: Candidemia is an important cause of healthcare-associated bloodstream infection, and chang- es in the distribution of Candida species may influence antifungal treatment strategies. This study aimed to determine the species distribution of yeasts isolated from blood cultures and evaluate their antifungal susceptibility profiles.

Materials and Methods: This retrospective study included 269 yeast isolates recovered from blood cultures between De- cember 2017 and December 2021. Species identification was performed using the VITEK 2 YST system. Antifungal suscep- tibility testing was performed using Sensititre YeastOne for 215 (79.9%) isolates and VITEK 2 AST-YS08 for 54 (20.1%). Minimum inhibitory concentration results were interpreted according to applicable CLSI species-specific clinical break- points.

Results: Of the 269 isolates, 112 (41.6%) were Candida albicans and 157 (58.4%) were non-albicans Candida. The most frequent non-albicans species were C. parapsilosis (n=73, 27.1%), Nakaseomyces glabrata (C. glabrata) (n=37, 13.8%), and 90 50 tropicalis (n=34, 12.6%). Fluconazole MIC /MIC values were 0.5/256 mg/L for C. albicans, 1/16 mg/L for C. parapsi- losis, 8/32 mg/L for C. glabrata, and 1/4 mg/L for C. tropicalis.

Conclusion: The predominance of non-albicans Candida, particularly C. parapsilosis, highlights the importance of contin- uous local surveillance. Methodological differences between commercial susceptibility testing systems should be considered when interpreting antifungal susceptibility results.