fungemia: a 12-year retrospective review of antimicrobial susceptibility patterns at a reference laboratory and tertiary care center.

UNLABELLED

The prevalence of invasive candidiasis caused by non- species is increasing. is an infrequent cause of candidemia but has been associated with decreased susceptibility to triazoles. Clinical data related to the infection with are sparse. Our study evaluated the antifungal susceptibility testing (AST) for isolates submitted to a reference laboratory over a 12-year period (2012-2023). AST patterns were examined using Clinical and Laboratory Standards Institute (CLSI) and European Committee on Antimicrobial Susceptibility Testing (EUCAST) epidemiological cutoff values (ECVs) and breakpoints. Where isolates were identified from patients treated at our institution, retrospective chart review was performed to describe patient risk factors, treatment approaches, and outcomes associated with fungemia. One hundred twelve blood culture isolates of were identified, and clinical data were available for 21 fungemic patients. A significant number of isolates (9.8-20.5%) were observed to be non-wild type for various triazoles. All isolates were susceptible to micafungin. A majority (76.2%) of cases of fungemia treated at our tertiary care center were hospital-acquired, and two-thirds of patients were immunocompromised at the time of diagnosis. Ten of the 21 patients died within 60 days of fungemia, although mortality was directly or partially attributed to fungemia in only four cases (19.0%). Echinocandins may be used for empiric therapy for until the results of AST are available. Further research is required to determine appropriate clinical breakpoints for triazoles.

IMPORTANCE

Our study addresses a significant knowledge gap in the clinical management of this non- species. Our retrospective review includes comprehensive AST data for 112 isolates, which is the largest number of isolates reported from the United States to date. Susceptibility data are supplemented by clinical outcomes, where isolates were identified for patients treated at Mayo Clinic. Key findings from our study include the observation that a notable proportion of isolates exhibit non-wild-type profiles for various triazoles. Importantly, all isolates remained susceptible to echinocandins, suggesting their efficacy as first-line therapy in the absence of timely susceptibility results. Furthermore, our study highlights the high mortality associated with fungemia in immunocompromised patients, emphasizing the urgent need for optimized treatment strategies.