Recent increase in Candida auris frequency in the SENTRY surveillance program: antifungal activity and genotypic characterization

We observed an increase in the frequency of Candida auris among invasive candidiasis isolates in the 2022 SENTRY Antifungal Surveillance Program compared to prior years: <= 0.1% before 2018, 0.4%-0.6% from 2018 to 2021, and 1.6% in 2022. C. auris isolates were collected in seven countries, but 28 (35.9%) isolates were recovered in the USA (five states; more common in New York, Texas, and New Jersey) and 26 (33.3%) in Panama. Greece and Turkey had 12 and 9 isolates, respectively. Overall, 82.1% of the isolates were resistant to fluconazole; 17.9% were resistant to amphotericin B; and 1.3% were resistant to caspofungin, anidulafungin, or micafungin (Centers for Disease Control and Prevention tentative resistance breakpoints). Rezafungin inhibited 96.2% of the isolates (Clinical and Laboratory Standards Institute susceptibility breakpoint). Pandrug resistance was not observed, but 17.9% of the isolates were resistant to fluconazole and amphotericin B. South Asian (Clade I) isolates were most common (n = 40, 51.3%); of these, 97.5% were resistant to fluconazole and 30.0% were resistant to amphotericin B. Thirty (38.5%) isolates belonged to the South American region (Clade IV), and 56.7% of those were resistant to fluconazole and 6.7% to amphotericin B. Seven isolates belonged to the South African Clade III and one to East Asian Clade II. Erg11 (Y132F, K143R, and F126L) and MRR1 (N647T) alterations were detected. One isolate that was resistant to all echinocandins carried an FKS R1354G alteration. Two isolates displayed elevated rezafungin minimum inhibitory concentration (MIC) values but low MIC values against other echinocandins and no FKS alterations. As C. auris is spreading globally, monitoring this species is prudent.