Identification of Cryptococcus neoformans（C neoformans） has been considered depends on the phenotype and biochemical characteristics

especially on its urease positive characteristics During the last ten years

there are 4 strains of urease negative C neoformans strains have been discovered

of which 2 were isolated from AIDS patients

1 from pigeon dropping and another 1 from preserved cultures of 286 strains of C neoformans So far

from medlines

there was none of urease negative strain isolated clinically from non AIDS patient was report Recently

we isolated a strain of urease negative strain of C neoformans from neither AIDS nor immunocompromised patients for the first time