Pulmonary Candidiasis Associated with COVID-19: Evaluation of Causative Agents and their Antifungal Susceptibility Patterns

Background: The purpose of the present study was to isolate Candida species from individuals with the COVID-19 disease and evaluate the susceptibility pattern of Candida spp. to routine antifungal drugs. Materials and Methods: A total of 25 Candida spp. isolated from hospitalized patients with COVID-19, who were suspected to have pulmonary candidiasis, and 26 archived Candida spp. specimens were enrolled in this study. For the identification of Candida spp., PCR was performed to detect and amplify the ITS1 and ITS4 genes. Then the products were subjected to the Msp I restriction enzyme to precisely identify the species. The amplification of the WHP1 gene was conducted to identify Candida albicans species. The antifungal activities of routine drugs and the synthesize AuNPs against Candida spp. were assessed based on the protocols presented by the Clinical and Laboratory Standards Institute M60 . Results: In the present study, C. albicans (24; 96%) and C. parapsilosis (1; 4%) were identified as the etiologic agents of the pulmonary candidiasis associated with the COVID-19 infection. Voriconazol and amphotericin B had superior activity against all the isolates in this study. Treatment with fluconazole and itraconazole did not significantly change the formation of colony-forming units (CFU). However, treatment with the AuNPs significantly decreased (within the range of 92-99.1%; P<0.05) the number of CFUs. Conclusion: The azole prophylaxis has likely been associated with the development of resistant isolates; the results of the present study suggested the promising role of novel antifungal agents such as AuNPs in overcoming drug resistant fungi.