P-820. Analyzing Trends in Candidemia: Insights from Routine Susceptibility Testing

TL;DR

This study tracks rising resistance in Candida species to antifungal drugs over time, highlighting the need for updated treatment strategies.

Contribution

The study provides new insights into temporal trends of antifungal resistance in Candida species from routine susceptibility testing.

Findings

Candida auris showed significant increases in fluconazole and micafungin resistance over time.

Candida krusei and C. parapsilosis showed increased amphotericin B non-susceptibility.

There was a significant rise in the isolation frequency of C. auris over the study period.

Abstract

Candidemia is associated with significant morbidity and mortality and rising healthcare costs. Echinocandins are recommended for empiric therapy. The aim of this study was to describe temporal trends in antifungal susceptibility results in Candida species to inform empiric treatment and antimicrobial stewardship efforts.Candida isolates by yearCounts of Candida species isolates identified each year.Candida species resistance trends over timeAntifungal Resistance Trends in Fluconazole, Micafungin and amphotericin B among select Candida species.

Candida isolates by year

Counts of Candida species isolates identified each year.

Candida species resistance trends over time

Antifungal Resistance Trends in Fluconazole, Micafungin and amphotericin B among select Candida species.

All non-duplicate Candida bloodstream isolates identified between May 11, 2017 through December 31, 2024 from a three-hospital healthcare system in Chicago were included. Isolates were identified by MALDI-TOF MS (Vitek MS, bioMérieux). Antifungal susceptibility testing was performed using an MIC method (YeastOne, Thermo Fisher). Minimal inhibitory concentrations (MICs) were interpreted using current CLSI breakpoints or epidemiologic cutoff values (ECVs) outlined in the M27M44SE and M57SE documents, respectively. Descriptive statistics were used to summarize microbiology data over time. The Cochran-Armitage trend test was used to analyze resistance and non-susceptibility to antifungal agents over time.

Over the period examined, we tested 1,070 Candida isolates. Candida albicans (439, 41%) was identified most frequently, followed by C. glabrata (275,25.7%), C. parapsilosis (110, 10.3%), C. auris (70, 6.5%), C. tropicalis (52, 4.9%) and C. krusei (51, 4.8%). The remaining 73 isolates were other Candida species (Table). We evaluated trends in resistance to three antifungal agents routinely reported: fluconazole (FLC), micafungin (MCF) and amphotericin B (AMB) (Figure). Among C. auris, there was a statistically significant increase in FLC (p=0.048) and MCF (p< 0.001) resistance over time. C. krusei (p=0.028) and C. parapsilosis (p=0.002) had statistically significant increases in AMB non-susceptibility, indicating more isolates with non-wild-type MICs over time.

In our laboratory, we observed a significant increase in the frequency of isolation of C. auris over time. Additionally, we observed an increase in FLC and MCF resistance in C. auris isolates over time and an increasing number of C. krusei and C. parapsilosis isolates with MICs to AMB above the ECV. These findings are concerning and warrant further investigation and collaboration with antimicrobial stewardship.

All Authors: No reported disclosures

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