Unveiling Profile Of Candidemia In A Tertiary Care Hospital In Bihar And Comparing Fluconazole And Amphotericin B Susceptibility Testing Methods In Candida Species: Broth Microdilution VS VITEK2 System

Background: Candidemia is a major healthcare concern, particularly in immunocompromised patients, with an increasing prevalence of non-albicans Candida species demonstrating antifungal resistance. Rapid and accurate identification of Candida species and antifungal susceptibility testing (AFST) are critical for appropriate management[1–6]. This study aims to characterize the species distribution of Candida isolates in a tertiary care hospital in Bihar and compare the essential and categorical agreement of Fluconazole and Amphotericin B susceptibility testing using the broth microdilution method versus the automated VITEK 2 system [7–9]. Methods: A total of 126 Candida isolates from bloodstream infections were identified using both conventional methods (Gram staining, germ tube test, CHROMagar, and Dalmau plate) and the automated VITEK 2 system [1, 2]. AFST for Fluconazole and Amphotericin B was performed using the Clinical and Laboratory Standards Institute (CLSI) M27/A3 broth microdilution method and the VITEK 2 system [8]. Essential and categorical agreement between the two methods was assessed [10]. Results: Among the isolates, 11.9% were Candida albicans , while 88.1% were non-albicans Candida , with Candida parapsilosis and Candida tropicalis being the most prevalent. The VITEK 2 system demonstrated high reliability, with 100% categorical agreement for Fluconazole and 95.4% for Amphotericin B compared to broth microdilution. Essential agreement was 98.4% for Fluconazole and 60.3% for Amphotericin B. The VITEK 2 system significantly reduced the time required for Candida speciation and susceptibility testing, enabling timely clinical decision-making. Conclusion: Candida speciation and antifungal susceptibility testing are crucial for guiding appropriate therapy and preventing resistance [7]. Non-albicans Candida species are emerging as significant pathogens, necessitating accurate identification and susceptibility testing [4–6]. The VITEK 2 system enhances Candida identification and antifungal susceptibility determination, offering a rapid and reliable alternative to conventional methods [8–10]. With high agreement rates for Fluconazole and Amphotericin B, it serves as an efficient tool for clinical decision-making. However, further research is needed to refine susceptibility testing methods and ensure optimal antifungal therapy.