Specific Identification of Candida Glabrata via Colorimetric Assay Based on Gold Nanoparticles

Candida glabrata is one of the most common Candida species which is able to get resistant to antifungals. So, the rapid identification of it, seems to be necessary for early treatment of infections. The conventional methods for detection of Candida species are time-consuming and difficult. Today, using of nanoparticles with unique properties has been expanded. The purpose of this study was rapid identification of Candida glabrata using colorimetric assay based on gold nanoparticles. Candida glabrata was cultured in yeast extract peptone dextrose broth medium and DNA was extracted. The gene specific sequence (CAGL0M05005g) was determined from the Candida genetic information bank. For polymerase chain reaction (PCR), the primers and probe were designed via Oligo 7 software. The PCR product and probe was affected by denaturation and optimized binding temperatures. The gold nanoparticles were added and changed the color to be visual; by using ultraviolet-visible (UV-vis) spectrophotometer and transmission electron microscopy (TEM), they were confirmed. To evaluate the sensitivity of new method, different concentrations of PCR product were used and the results were analyzed using gel electrophoresis. The optimum temperatures of the primer binding to the DNA template and hybridization the probe was determined. After adding gold nanoparticles, the mixture solution color was changed from red to purple. The results were confirmed via spectroscopy and electron microscopy. The results indicated that in detection of Candida glabrata, the new method is faster than conventional methods and more sensitive than gel electrophoresis.