Candida auris Identification and Antifungal Susceptibility — Taiwan, 2017–2023

DOI: 10.6524/EB.202501_41(2).0001

Shu-Ying Li^*, Kwo-Wei Chen, Mei-Hui Liao

2025 Vol.41 NO.2

Correspondence Author： Shu-Ying Li^*

Abstract：

        In recent years, Candida auris infections had risen globally, and posed a major threat to the global healthcare system because of its high mortality rate of invasive infection, multi-drug resistance, and potential for nosocomial transmission. Accurate and efficient identification of C. auris and determination of their antifungal susceptibility are crucial for patient treatment and epidemic control.
We collected 24 suspected C. auris isolates across the country from 2017 to 2023 and identified them using MALDI-TOF, ITS1-5.8S-ITS2 gene, and 28S rRNA gene sequencing. The identification results were 2 C. auris, 14 C. haemulonii, 6 C. duobushaemulonii, 1 C. lusitamoae, and 1 C. parapsilosis. Antifungal susceptibility testing for amphotericin B, fluconazole, itraconazole, voriconazole, posaconazole, flucytosine, caspofungin, micafungin, and anidulafungin were carried out against the 2 strains of C. auris. Among these, determination of resistance to amphotericin B, fluconazole, caspofungin, micafungin, and anidulafungin followed the susceptibility criteria from the US Centers for Disease Control and Prevention (US CDC). There were no drug resistance found, except one strain with MIC showing caspofungin resistance (8 μg/ml). Considering that the resistance genes ERG11 and FKS1 of this suspected caspofungin-resistant strain had not mutated, the MIC of other echinocandins was low, and possible Eagle effect, this strain was not classified as caspofungin-resistant. Many previous studies have also shown that determining drug resistance using MIC still has limitations. In addition to using the criteria recommended by US CDC, drug resistance determination should be interpreted with caution and supplemented by drug resistance gene detection methods.