Early warning bells: Emergence of fluconazole resistance in Candida parapsilosis

ABSTRACT

Objectives: To study the susceptibility patterns in blood isolates of Candida parapsilosis at a tertiary care center. Method(s) This was a retrospective observational study of nine cases of candidemia due to C. Parapsilosis over a period of 1 year. Data were collected using the hospital's electronic health records. Species identification was done using Matrix-Assisted Laser Desorption and Ionization-Time of Flight Mass Spectrometry (MALDI-T OF-MS) (Bruker Biotyper Sirius-Bruker Dalton-ics, Bremen, Germany). Antifungal susceptibility was performed by broth microdilution method using Sensititre TM YeastOne TM YO1O AST Plates (Therm ofisher Scientific, USA). Result(s) All patients with C. parapsilosis bloodstream infection had central venous access and all patients had received broad-spectrum antibiotics atthe time of developing candidemia.Fourpatients developed C.parapsilosis candidemiain the post coronavirus disease 2019 (COVID 19) setting.Out of the 9 isolates, 7 (77.7%) were resistant to fluconazole, 2 were resistant to voriconazole and posaconazole, and 1 isolate was resistant to amphotericin.A total of 4/9 patients were started on fluconazole prior to antifungal susceptibility testing;3 of these needed to be switched to an echinocandin due to fluconazole resistance. Conclusion(s) Fluconazole resistance in this study was seen in 7/9 (77.7%) isolates which is more than what has been previously described for C. parapsilosis. This makes fluconazole a poor choice for the treatment of C. parapsilosis in our institute. These findings may have an implication in the selection or de-escalation of antifungal treatment for C. parapsilosis.