Species Distribution and Antifungal Susceptibilities of Candida Species Isolated From Blood Culture

Cureus. 2023 Apr 27;15(4):e38183. doi: 10.7759/cureus.38183. eCollection 2023 Apr.

Abstract

Introduction Candida species (spp.) are among the leading agents of bloodstream infections. Candidemias are a major cause of morbidity and mortality. Having an understanding of Candida epidemiology and antifungal susceptibility patterns in each center is crucial in guiding the management of candidemia. In this study, the species distribution and antifungal susceptibility of Candida spp. isolated from blood culture at the University of Health Sciences, Bursa Yuksek Ihtisas Training & Research Hospital were examined and the first data on the epidemiology of candidemia in our center were presented. Methods A total of 236 Candida strains isolated from blood cultures in our hospital over a four-year period were analyzed and their antifungal susceptibilities were studied retrospectively. Strains were identified at the species complex (SC) level by the germ tube test, morphology in cornmeal-tween 80 medium, and the automated VITEK 2 Compact (bioMérieux, Marcy-l'Étoile, France) system. Antifungal susceptibility tests were performed on VITEK 2 Compact (bioMérieux, Marcy-l'Étoile, France) system. The susceptibilities of the strains to fluconazole, voriconazole, micafungin, and amphotericin B were determined according to Clinical and Laboratory Standards Institute (CLSI) guidelines and epidemiologic cut-off values. Results Of the Candida (C.) strains, 131 were C. albicans (55.5%), 40 were C. parapsilosis SC (16.9%), 21 were C. tropicalis (8.9%), 19 were C. glabrata SC (8.1%), eight were C. lusitaniae (3.4%), seven were C. kefyr (3.0%), six were C. krusei (2.6%), two were C. guilliermondii (0.8%) and two were C. dubliniensis (0.8%). Amphotericin B resistance was not detected in Candida strains. Micafungin susceptibility was 98.3%, and four C. parapsilosis SC strains (10%) were intermediate (I) to micafungin. Fluconazole susceptibility was 87.2%. Apart from C. krusei strains which intrinsically resistant to fluconazole, three C. parapsilosis (7.5%), one C. glabrata SC (5.3%) strain were resistant (R) to fluconazole, and one C. lusitaniae (12.5%) strain was wild-type (WT). Voriconazole susceptibility of Candida strains was 98.6%. Two C. parapsilosis SC strains were I to voriconazole, while one strain was R. Conclusion In this study, the first epidemiological data of candidemia agents in our hospital were presented. It was determined that rare and naturally resistant species did not cause any problem in our center yet. C. parapsilosis SC strains showed decreased susceptibility to fluconazole, whereas Candida strains were highly susceptible to the four antifungals tested. Close monitoring of these data will help guide the treatment of candidemia.

Keywords: blood culture; candida; candidemia; epidemiology; fungal infections.