Stability of candida albicans over long and short term storage in a resource-limited setting

Abstract

BACKGROUND: Candida albicans are widely isolated fungal yeast agents from clinical samples. Several storage methods for fungi have evolved overtime and they are not without setbacks. Preservation method is critical for research,training and teaching.In resource–poor setting,the method to employ must be cheap and easy to maintain with minimal risk of contamination as well as degeneration of the organisms.We thus,set out to study the stability of Candida albicans over long and short term storage in a resource-limited setting.METHODS: One hundred Candida albicans strains isolated from patients with vulvovaginal candidiasis and oral candidiasis were preserved in triplicates using sterile distilled water,Chromagar plate,mineral oil overlay and brain heart infusion broth plus 10% glycerol at -20OC.Recovery rates were determined at six months,12 months and 18 months by sub-culturing onto sabouraud dextrose agar.RESULT: The recovery rate of C. albicans was 100% for all the preservation methods used during the six months storage,mineral oil overlay and brain heart infusion broth plus 10% glycerol for the 12months storage,and only the brain heart infusion broth plus 10% glycerol during the 18months storage.CONCLUSION: Candida albicans can be preserved over long period of time in resource- limited setting where power supply is erratic using brain heart infusion broth plus 10% glycerol at -20OC and mineral oil overlay technique whereas for short term preservation, sterile distilled water and taped culture plates technique can be used. Preservation of Candida albicans isolates in resource- limited setting over short or long term period is possible and affordable depending on the technique employed.KEYWORDS: Candida albicans, preservation, sterile distilled water, Chromagar plate, mineral oil overlay, brain heart infusion broth.