Necessity to identify candida species accurately with minimum inhibitory concentration determination in each case of bloodstream infections

Abstract

Background: Bloodstream Candida infection is a life-threatening event among ICU admitted patients. This infection is caused by a diverse range of Candida species having varied minimum inhibitory concentrations. Objectives: To identify Candida species causing bloodstream infections with their antifungal susceptibility determination. Methods: Candida species isolated from the blood of ICU admitted patients were identified by phenotypic as well as by molecular methods including PCR-RFLP using MspI restriction enzyme and MALDI TOF MS. The minimum inhibitory concentration of fluconazole, voriconazole, amphotericin B and caspofungin was determined against isolated Candida species by CLSI M27A3 guidelines. Results: A total of 119 Candida species were isolated. Among them, C. tropicalis(n = 29) was the predominant isolate followed by C. parapsilosis(n = 18), C. glabrata (n = 12), C. krusei (n = 11) and C. albicans(n = 11). Uncommon Candida species isolated were; Wickerhamomyces anomalus(n = 15), Kodaemia ohmeri(n = 8), C. lusitaniae (n = 5) and C. auris (n = 2). A varied antifungal MIC values were observed. Caspofungin had the lowest MIC among the tested antifungals. Increased fluconazole MIC was observed against the isolated Candida species including C. tropicalis. All the isolated C. lusitaniae and C. auris strains have ≥1mcg/ml amphotericin B MIC. In comparison to fluconazole, voriconazole was more effective when tested in vitro. Conclusion: Emergence of uncommon Candida species having varied antifungal MIC warns the physicians to have a prompt, accurate identification with antifungal MIC determination in each case of bloodstream Candida infections. Keywords: Caspofungin, Fluconazole, Amphotericin B, C.tropicalis, C. auris, W. anomalus