Speciation of candida and antifungal susceptibility testing from clinical specimens in a tertiary care hospital, Bangalore

Objective: Candida albicans is generally considered the major pathogen among the Candida species. An increase in the prevalence of non-albicans Candida species has been noted during the last decades and also azole resistance is seen more commonly in non-albicans Candida species compared to Candida albicans. The objective of the study was to identify, isolate and speciate Candida and perform antifungal susceptibility testing from various clinical specimens which has a direct impact on choice of empirical antifungal treatment. Methodology: A total of 100 Candida isolates from various clinical specimens were processed for speciation using standard mycology methods. Antifungal susceptibility testing was performed by disc diffusion method according to CLSI guidelines M44-A2. Results: The present study had a male preponderance, with an overall male: female ratio being 1.4:1. Isolation of Candida was highest among the extremes of age group i.e., neonates followed by 50-70 yrs. The various species of Candida isolated in the study were C.tropicalis (39%), C.albicans (35%), C.krusei (13%), C.glabrata (7%) and C.parapsilosis (6%). There was variation in the susceptibility pattern of Candida spp. to frequently used antifungal drugs. The Candida species showed highest sensitivity to Nystatin (98.92%) and Amphotericin B (84.95%) followed by Fluconazole (42.53%), Clotrimazole (30.12%) and Ketoconazole (25.8%). C.tropicalis, C.albicans and C.parapsilosis were 100% sensitive to Nystatin. C.krusei was 100% sensitive to Clotrimazole and 92.3% sensitive to Amphotericin B and Nystatin. The susceptibility of C.albicans to fluconazole was only 60%. Conclusion: Non-albicans Candida is gaining clinical significance. Hence identification of species will be helpful in selection of antifungals for the earlier and cost effective treatment. CHROM agar serves as a primary isolation and differentiation medium for clinical specimens that could allow laboratories to rapidly identify Candida spp, enabling clinicians to choose appropriate antifungal agents, thus decreasing patient’s morbidity and mortality.