Species identification and antifungal susceptibility of Candida isolated from urine specimens in a tertiary care hospital

Abstract

Introduction and Objectives: Urinary tract infections caused by Candida have become frequent as a result of increased use of broad spectrum antibiotics, corticosteroids, immunosuppressive agents, bladder catheters and increasing cases of diabetes mellitus. The morbidity and mortality caused by non-albicans Candida (NAC) species are increasing. A prospective study was done to study the incidence of non-albicans Candida in patients with urinary tract infection. Materials and Methods: The speciation of Candida isolated from urine samples of patients was done using conventional yeast identification protocols and chrome agar. Antifungal susceptibility testing was done by the disc diffusion method to amphotericin B, nystatin and azoles. Results: Candiduria was diagnosed in 1.3% of patients with urinary tract infection. Six species of Candida were isolated, which include C.albicans (36.8%), C. tropicalis (22.9%), C. krusei (13.6%), C. parapsilosis (13.6%), C. guilliermondii (5.2%) and C. kefyr (7.9%). All Candida albicans isolates were sensitive to Amphotericin B and nystatin. Ketoconazole was the next effective drug (75%), followed by clotrimazole (71.42%), fluconazole (70.6%) and itraconazole (62.5%). Amongst the non-albicans Candida species, Nystatin was the most sensitive drug (89%), followed by Amphotericin B (64%), fluconazole (62.2%), itraconazole (58.8%), clotrimazole (58.8%) and ketoconazole (47%). Conclusion: Urine samples yielded more of non-albicans Candida. Among the non-albicans Candida, Candida tropicalis was the predominant isolate. Antifungal resistance was more in non-albicans Candida than in Candida albicans. Hence there is need for speciation and susceptibility testing of Candida species to optimize the selection of antifungal agents to provide the best possible patient care. Keyword: Candiduria, antifungal susceptibility testing, Candida speciation, Chrome agar, urinary tract infection, Non albicans Candida.