Analysis of Antifungal Drug Resistance Among Candida Spp. and Other Pathogenic Yeasts Isolated from Patients in Eastern Poland: Diagnostic Problems.

OBJECTIVE

The profile of Candida species and their sensitivity to antifungal drugs isolated from patients in Eastern Poland were analyzed. Identification and drug resistance interpretation issues for clinically significant rare species were investigated.

METHODS

A total of 197 yeast isolates were analyzed. Fungal identification was conducted using biochemical tests and MALDI-TOF. Minimum inhibitory concentrations (MICs) were determined for amphotericin B, fluconazole, itraconazole, voriconazole, isavuconazole, posaconazole, caspofungin, micafungin, and anidulafungin. Interpretation of results was based on the EUCAST, CLSI recommendations, and available literature.

RESULTS

The following species were identified: Candida albicans (n=78), C. glabrata (Nakaseomyces glabrata) (n=30), C. dubliniensis (n=23), C. krusei (Pichia kudriavzevii) (n=13), C. parapsilosis (n=13), C. tropicalis (n=7), C. kefyr (Kluyveromyces marxianus) (n=6), C. lusitaniae (Clavispora lusitaniae) (n=6), C. lipolytica (Yarrowia lipolytica) (n=3), C. famata (Debaryomyces hansenii) (n=2), C. intermedia (n=2), C. guillermondii (Meyerozyma guilliermondii) (n=2), C. ciferrii (n=1), C. orthopsilosis (n=1), C. pelliculosa (Wickerhamomyces anomalus) (n=1), C. shehatae (n=1), C. fabianii (Cyberlindnera fabianii) (n=1), Cryptococcus humicola (Vanrija humicola) (n=4), and Saccharomyces cerevisiae (n=3). The highest percentage of resistant strains was reported for C. albicans, C. glabrata, C. parapsilosis, C. tropicalis, and C. lusitaniae.

CONCLUSION

Among the studied isolates, rare Candida species were identified. Their identification in routine diagnostics can be challenging, necessitating the use of MALDI-TOF MS. The wide spectrum of isolated species may complicate the establishment of a targeted antifungal therapy due to the lack of reference MIC ranges for the interpretation of antibiograms. Gradient strips are an accurate, reproducible, and convenient method for MIC determination.