Isolation, speciation and antifungal susceptibility testing of Candida isolates from various clinical specimens at a tertiary care hospital, Nepal

Sundar Khadka,Bharat Mani Pokhrel,Hari Prasad Kattel,Keshab Parajuli,Narayan Parajuli,Sulochana Khatiwada,Shyam Kumar Mishra,Jeevan Bahadur Sherchand,Sangita Sharma,Basista Prasad Rijal,Manoj Pradhan,Niranjan Shah,Subhash Dhital

doi:10.1186/s13104-017-2547-3

Abstract

BackgroundCandida species are responsible for various clinical infections ranging from mucocutaneous infection to life threatening invasive diseases along with increased resistance to antifungal drugs has made a serious concern. Resistance to antifungal agents has increased during the last decade. Thus, identification of Candida up to species level and its antifungal susceptibility testing has a paramount significance in the management of Candidal infections. The aim of the study was to speciate Candida species and to determine antifungal susceptibility pattern of Candida species to antifungal agents.MethodsA total of 100 consecutive Candida species were isolated from 1248 clinical specimens over 7 months period. Growths on Sabouraud dextrose agar were evaluated for colony appearance, macroscopic examination, Gram staining, germ tube test and urea hydrolysis test. Further, they were processed for Candida speciation on CHROMagar. Antifungal susceptibility testing was performed as recommended by Clinical and Laboratory Standards Institute (CLSI) M44-A document.ResultsOut of 100 Candida isolates, Candida albicans (56%) was the most common species. Among the non-albicans Candida species, Candida tropicalis (20%) was the predominant isolate followed by Candida glabrata (14%). Regarding antifungal susceptibility pattern, Candida species were more susceptible to clotrimazole (82%) followed by fluconazole (64%) and miconazole (44%).ConclusionsCandida albicans was the predominant species responsible for various Candidal infections. Among commonly used antifungal drugs clotrimazole, miconazole and fluconazole were most effective.

Highlights

Candida species are responsible for various clinical infections ranging from mucocutaneous infection to life threatening invasive diseases along with increased resistance to antifungal drugs has made a serious concern
We explored the characterization of Candida species using CHROMagar and showed the susceptibility pattern of Candida isolates from clinical specimens
Among the non-albicans Candida (NAC) spp., C. tropicalis (20%) was the commonest isolate followed by C. glabrata (14%) and C. krusei (10%) respectively

Summary

Introduction

Candida species are responsible for various clinical infections ranging from mucocutaneous infection to life threatening invasive diseases along with increased resistance to antifungal drugs has made a serious concern. Resistance to antifungal agents has increased during the last decade. Identification of Candida up to species level and its antifungal susceptibility testing has a paramount significance in the management of Candidal infections. The commonly used antifungal drugs show significant variation in the susceptibility pattern among the types of Candida species. Several previous studies reported the emergence of drug resistance Candida species in global scenario [5, 6]. The isolation, identification, characterization and susceptibility testing of Candida species in clinical specimens have become increasingly important for management of fungal infections. CHROMagar medium is an easy, rapid and reliable method to isolation and for differentiation of four types of Candida species [7]

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