Identification and Antifungal Drug Susceptibility Pattern of Candida auris in India

Candida auris has turned up as a multidrug-resistant nosocomial agent with outbreaks reported worldwide. The present study was conducted to evaluate the antifungal drug susceptibility pattern of C. auris.

Isolates of C. auris were obtained from clinically suspected cases of candidemia from January 2019 to June 2021. Identification was done with matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF) and panfungal DNA polymerase chain reaction (PCR), followed by sequencing. Antifungal susceptibility testing was performed with broth microdilution method.

Out of 50 isolates C. auris, 49 were identified by MALDI-TOF and one isolate was identified with panfungal DNA PCR followed by sequencing. For fluconazole, 84% (n = 42) isolates were found to be resistant and 16% (n = 8) isolates were susceptible (minimum inhibitory concentrations [MICs] range 0.5-16). Posaconazole exhibited potent activity, followed by itraconazole. For amphotericin B, only 6% (n = 3) isolates were resistant with MICs ≥2 μg/mL. Only 4% (n = 2) isolates exhibited resistance to caspofungin. No resistance was noted for micafungin and anidulafungin. One (2%) isolate was found to be panazole resistant. One (2%) isolate was resistant to fluconazole, amphotericin B, and caspofungin.

Correct identification of C. auris can be obtained with the use of MALDI-TOF and sequencing methods. A small percentage of fluconazole-sensitive isolates are present. Although elevated MICs for amphotericin B and echinocandins are not generally observed, the possibility of resistance with the irrational use of these antifungal drugs cannot be denied. Pan azole-resistant and pan drug-resistant strains of C. auris are on rise.