Trends in Susceptibility pattern of Candida species to Fluconazole and Amphotericin B at a tertiary care center in South India

Johanna N Sem,
Dr. Raghavendra Rao Morubagal,
Dr. Sowmya G Shivappa,
Dr. Ranjitha Shankare Gowda,
Dr. Rashmi P Mahale,
Dr. Tejashree A Urs,
Vidyavathi B Chitharagi*

Abstract

Aims and Objectives: To determine the fluconazole and Amphotericin B susceptibility pattern among candida isolates by disk diffusion, Vitek-2 method, and micro-broth dilution methods (MBD) Introduction: Fungal infections are now becoming more prevalent than bacterial in causing opportunistic and nosocomial infections. Candida species are among the most common invasive fungi that are seen in most patients with predisposing co-morbidities such as diabetes and hypertension. Therefore; identification of the species and antifungal susceptibility testing is essential for proper patient management as various species respond differently to antifungals and for the prevention of emergence of drug resistance. Methods: Candida species isolated from different specimens were included in the study, speciation of the isolates was achieved by Vitek 2 automated machine and also with corn meal agar inoculation (CMA). The comparison of antifungal susceptibility testing was done by three different methods which included Vitek 2 systems, disk diffusion, and Micro-broth dilution methods. The antifungal susceptibility was tested for fluconazole and Amphotericin B. Results: A total of 50 Candida isolates were randomly selected and speciated. Species-wise distribution showed C. tropicalis to be the most common one accounting for 34 (69%) followed by C. albicans 12(24%) and 4 (12%) of them were C. parapsilosis. The overall resistance among these isolates was as follows: by micro –broth dilution fluconazole resistance to Candida species was 6% and to Amphotericin B was 8%. By disc diffusion, fluconazole resistance was 10%, Amphotericin B was 14%. With the Vitek 2 system, fluconazole and Amphotericin B showed resistance of 10% and 6% respectively. Conclusion: Speciation and Antifungal susceptibility testing of Candida isolates are of great significance regardless of the specimen isolated from, which helps in the management and knowing the epidemiology of the susceptibility pattern of the Candida species. For this to become a reality a reliable, easy, and sensitive method of antifungal susceptibility needs to be used in every Microbiology laboratory as a routine practice.