Efficacy of CHROMagar for Diagnosis of Candida Species

Abstract

Catheter associated urinary tract infections are nosocomial (10-15%) and almost all are caused by Candida spp. Infections caused by non-Candida albicans species are also emerging.In order to facilitate rapid identification, such as Chromogenic media have been developed. These special media yield microbial colonies with varying  pigmentation. CHROMagar employs this methodology to allow differentiation of several Candida yeasts by colour and morphology. The study has been carried out with the aim to find the rate of nosocomial candiduria in catheterised patients and compare CHROMagar with sugar assimilation test for species identification of Candida. The present study was carried on 500 urine samples of catheterized patients irrespective of age and sex from MMIMSR, mullana. Urine aspiration was done with 5ml sterile syringe after disinfecting the catheter area to be punctured First sample was collected at the time of admission and then, after 72 hrs of admission . The samples were cultured on Sabouraud’s dextrose agar and identification done by colony morphology and Gram staining. Species confirmation done by Morphology on CHROMagar and Sugar assimilation test. The rate of isolation of culture positive patients (33.8%) amongst total number of catheterized patients with p value <0.001 which is significant. The predominance of bacteria as causative organism of UTI in catheterized patients over fungi.The positivity rate of bacterial culture was 59.1% whereas 40.8% for fungal culture. The study showed a p value of < 0.001 which is highly significant.Out of 500 samples 60(12%)showed the growth of Candida species. Candida albicans(66.6%) was predominant  pathogen  . Within 48 hrs all three species showed growth on CHROM agar while sugar assimilation took more than 72 hours. Morphology of 38(95%) candida albicans  were light green,C. tropicalis 11(91.6%) blue purple while C. galabarata 7(87.5) showed purple colour. The sensitivity of Chromagar as for Candida species was 93.3%, significant p value of 0.032