National Surveillance of Candidemia in the Czech Republic: Preliminary Results from the 2023 Multicentre Study.

This study aimed to obtain data describing the epidemiology and antifungal susceptibility of yeasts isolated from bloodstream infections (BSI) in the Czech Republic (CR). This study presents data from the first year of a national, long-term surveillance program. All microbiologically confirmed candidemia cases in patients hospitalized at 30 Czech centers in 2023 were evaluated. This study assessed BSI incidence per 100,000 inhabitants, species distribution, and antifungal susceptibilities (EUCAST E.Def 7.4 protocol) of strains.aff Whole-genome sequencing was performed on selected isolates with acquired resistance or non-wild-type phenotypes to determine the molecular mechanisms of resistance. In total, 433 isolates from 408 unique BSI episodes in 398 patients were recorded in 2023. Candida albicans was the most frequent species (40.6%), followed by Candida glabrata (24.5%), Candida parapsilosis (14.5%), and Candida tropicalis (5.5%). In pediatric patients, C. albicans (58.8%) was the most common, followed by C. parapsilosis (17.6%). Candida auris BSI was not detected in 2023. The highest rates of acquired fluconazole resistance were detected in C. parapsilosis (16.9%) and C. glabrata (15.4%). Most fluconazole-resistant (FLC-R) C. parapsilosis isolates carried Y132F mutation in ERG11 gene (14/15; 93.3%). One isolate of C. glabrata was resistant to echinocandins (1.3%), but remained susceptible to azoles, mutations in FKS1 (G14S) and FKS2 (S663P, T926P) were identified. This nationwide survey provides the first comprehensive yeast BSI surveillance data from the Czech Republic, which spans the entire country. CR follows trends observed in developed countries, with a decline in C. albicans and a rise in C. glabrata infections. To our knowledge, this is the first report describing FLC-R C. parapsilosis isolates carrying the Y132F ERG11 mutation in CR. These findings highlight several emerging challenges that reflect global trends: a shifting spectrum of Candida species from C. albicans to non-albicans species, and rising levels of acquired azole resistance. Therefore, continuous national monitoring is essential.