Molecular identification and antifungal susceptibility profiles of Candida parapsilosis complex species isolated from culture collection of clinical samples

Abstract

Introduction: Candida parapsilosis is a common yeast species found in cases of onychomycosis and candidemia associated with infected intravascular devices. In this study, we differentiated Candida parapsilosis sensu stricto, Candida orthopsilosis, and Candida metapsilosis from a culture collection containing blood and subungual scraping samples. Furthermore, we assessed the in vitro antifungal susceptibility of these species to fluconazole, itraconazole, voriconazole, posaconazole, amphotericin B, and caspofungin. Methods: Differentiation of C. parapsilosis complex species was performed by amplification of the secondary alcohol dehydrogenase (SADH) gene and digestion by the restriction enzyme BanI. All isolates were evaluated for the determination of minimal inhibitory concentrations using Etest, a method for antifungal susceptibility testing. Results: Among the 87 isolates, 78 (89.7%) were identified as C. parapsilosis sensu stricto, five (5.7%) were identified as C. orthopsilosis, and four (4.6%) were identified as C. metapsilosis. Analysis of antifungal susceptibility showed that C. parapsilosis sensu stricto isolates were less susceptible to amphotericin B and itraconazole. One C. parapsilosis sensu stricto isolate was resistant to amphotericin B and itraconazole. Moreover, 10.2% of C. parapsilosis sensu stricto isolates were resistant to caspofungin. Two C. parapsilosis sensu stricto isolates and one C. metapsilosis isolate were susceptible to fluconazole in a dose-dependent manner. Conclusions: We reported the first molecular identification of C. parapsilosis complex species in State of Goiás, Brazil. Additionally, we showed that although the three species exhibited differences in antifungal susceptibility profiles, the primary susceptibility of this species was to caspofungin.