A RAPID UREASE TEST FOR PRESUMPTIVE IDENTIFICATION OF CRYPTOCOCCUS-NEOFORMANS

A rapid method to evidence urease activity is described. Urea hydrolys is and consequent production ammonia are detected by a chemical reacti on producing a blue phenol compound (indophenol blue). Three hundred a nd three yeast were tested. Out of 107 urease-positive organisms detec ted by Christensen's Urea Agar Test (CUAT) 102 were positive by our me thod. No false negatives were observed by this method when testing 87 Cryptococcus strains. Ths practical screening test for presumptive ide ntification of Cryptococcus neoformans is simple, unaffected by pH cha nges and requires 15 minutes to be performed.