Detection and Identification of Candida auris and Candida kefyr from Different Clinical Samples by Conventional and Molecular Methods

Abstract

Background:    Candidiasis is an opportunistic fungal disease. Some Candida species (Candida spp.) exhibit greater resistance to antifungals, leading to difficulty in treatment.
Objective:    To search for pathogenic C. auris and C. kefyr isolates from specimens taken up from patients admitted to Kirkuk hospitals, to test their susceptibilities to various antifungals, and the genetic background for their antifungal resistance pattern.
Methods:    The study comprised the collection of 1047 samples. All isolated Candida spp. were identified morphologically by direct and indirect methods, and then subjected to antifungal susceptibility testing. Polymerase chain reaction (PCR) was used for identification of Candida spp. and detection of resistance genes.
Results:    Among the total samples, 215 were positive for Candida spp. C. auris has not been detected, and four isolates of C. kefyr were found: two isolates from urine samples and the others from wound swabs. All of C. kefyr isolates displayed amphotericin resistance. Regarding azoles, all isolates were sensitive, excluding one isolate that was found to be voriconazole and 5-flucytosine resistant. Ergosterol3 (ERG3), ERG6, and ERG11 genes were expressed in all isolates. The ERG2 was not found in isolate number 3, contrary to the uracil phosphoribosyl transferase (FUR1) gene, which was noted only in this isolate.
Conclusion:    The extreme resistance to amphotericin B occurred by the increased expression of ERG3, ERG6, and ERG11genes. The expression of the FUR1 gene was responsible for resistance against the 5-flucytosine.
Keywords:    Candida auris, Candida kefyr, antifungals, amphoterecin B.
Citation:    Zeynel AA, Al-Attraqchi AAF, Jasim HM. Detection and identification of Candida auris and Candida kefyr from different clinical samples by conventional and molecular methods. Iraqi JMS. 2025; 23(2): 328-347. doi: 10.22578/IJMS.23.2.16