Genomic epidemiology of human candidaemia isolates in a tertiary hospital.

Invasive candida infections are significant infections that may occur in vulnerable patients with high rates of mortality or morbidity. Drug-resistance rates also appear to be on the rise which further complicate treatment options and outcomes. The aims of this study were to describe the prevalence, molecular epidemiology, and genetic features of bloodstream isolates in a hospital setting. The resistance mechanisms towards the two most commonly administered antifungals, fluconazole and anidulafungin, were determined. Blood culture isolates between 1 January 2018 and 30 June 2021 positive for spp. were included. Susceptibility testing was performed using Etest. Whole-genome-sequencing was performed using Illumina NovaSeq with bioinformatics analysis performed. A total of 203 isolates were sequenced: 56 . 53 . , 44 . 36 . complex (consisting of and ), six . five . , and three . . A single cluster of azole-resistant and four clusters of isolates were observed, suggesting possible transmission occurring over several years. We found 11.3%, and 52.7 % of and , respectively, clustered with other isolates, suggesting exogenous sources may play a significant role of transmission, particularly for . The clusters spanned over several years suggesting the possibility of environmental reservoirs contributing to the spread. Limited clonality was seen for . Several sequence types appeared to be dominant for however the SNP differences varied widely, indicating absence of sustained transmission.