Characterisation and Antifungal susceptibility pattern of Candida species isolated from various clinical samples at a tertiary care centre in South India

Abstract

Background: Over the last 20 years, the rates of fungal infection have increased and Candida has emerged as a major cause of human disease. Furthermore there is an increase in nonalbicans candida species in many countries. The emerging pathogens are resistant to conventional antifungal therapy. Objective: To find out which species of Candida is predominant in clinical infection and determinate their antifungal susceptibility patter. Materials and method: All Candida isolates recovered from various clinical samples during the period from February 2011 to August 2012 were studied. The isolates were speciated using, both conventional and automated techniques. Antifungal susceptibility testing was done by disk diffusion methods according to Clinical and Laboratory Standards Institute guidelines. Various risk factors associated with the candida infection were also looked into. Results: A total of 269 Candida isolates were isolated. (Prevalence of 5.3%). 42% of isolates were from patients above 60 years of age Candida tropicalis (46%) was the most common isolate. All the 269 Candida isolates (100%) were sensitive to amphotericin B. Resistance of more than 70% to the three azoles tested was noted amongst the C albicans and the C parapsilosis spp. The risk factors commonly associated with candida infection were Catheterization (87.5%), ventilator assistance (75%) and Diabetes mellitus (31%). Conclusion: In our study Candida tropicalis was the predominant isolate. All candidal isolates were sensitive to Amphotericin B however marked resistance to azole derivative was found with Candida albicans than C.tropicalis. CHROMagar candida medium and tetrazolium reduction medium are found to be useful in identification of Candida species. All candidal isolates were sensitive to Amphotericin B. Keywords: Candida species, Anti-fungal susceptibility, Amphotericin B, Azole resistance