# Antifungal susceptibility profiles of candidemia isolates on the east coast of Peninsular Malaysia and reliability of Etest compared to Sensititre YeastOne

## TL;DR

This study examines antifungal resistance in Candida species from Malaysia's east coast and finds that Etest may be unreliable for determining drug susceptibility.

## Contribution

The study provides new insights into the prevalence of drug-resistant non-albicans Candida species and evaluates the reliability of Etest versus Sensititre YeastOne.

## Key findings

- Non-albicans Candida species (NACs) dominated candidemia cases (82%) with C. parapsilosis, C. tropicalis, and C. glabrata being most common.
- Etest showed poor agreement with SYO for fluconazole and anidulafungin, with high error rates indicating its unreliability as a stand-alone method.
- Echinocandins and amphotericin B remained highly effective, while azole resistance was notable in C. tropicalis and C. glabrata.

## Abstract

Candidemia is a major cause of morbidity and mortality worldwide. The rising prevalence of non-albicans Candida species (NACs), which often show diverse antifungal susceptibility, complicates treatment. This study aimed to characterize the species distribution and antifungal susceptibility of Candida isolates from candidemia cases on the east coast of Peninsular Malaysia and to evaluate the reliability of Etest compared to Sensititre YeastOne (SYO). A cross-sectional study collected 143 Candida blood culture isolates from several hospitals on the east coast of Peninsular Malaysia between February 2019 and January 2020. Species identification was performed using conventional methods and MALDI-TOF MS. Antifungal susceptibility testing was conducted with SYO and Etest. MIC results were interpreted using CLSI and EUCAST guidelines. Agreement between methods was assessed by essential and categorical agreement and error rates. NACs predominated (82%), with C. parapsilosis (27.3%), C. tropicalis (24.5%), and C. glabrata (21%). Echinocandins and amphotericin B showed high susceptibility rates (96.2% and 91.5%, respectively). Azole resistance was notable, especially in C. tropicalis and C. glabrata. Etest demonstrated an inconsistent agreement with SYO, particularly for fluconazole and anidulafungin, with high major and very major error rates. NACs dominate candidemia in Malaysia’s east coast, with significant azole resistance, while echinocandins and amphotericin B remain effective. Comparative analysis demonstrated poor agreement and elevated error rates for Etest relative to SYO, particularly for azoles and anidulafungin, indicating its unreliability as a stand-alone method. Continued local surveillance and validated AFST methods are critical to guide effective antifungal therapy.

This study highlights the evolving epidemiology of candidemia in Malaysia's east coast, marked by rising dominance of drug-resistant non-albicans Candida species. Findings underscore the value of reliable susceptibility testing, demonstrating that the widely used Etest method may misclassify resistance status, potentially impacting treatment choices. These insights inform stewardship efforts and clinical management in resource-constrained settings.