Abstract: Polymerase chain reaction(PCR) was used for the first time in China for the diagnosis of cryptococcal meningitis by amplification of specific sequence of the rDNA genes of C.neoformans.All 11 strains of C.neoformans yielded a specific 136 bp fragment but 21 non-C.neoformans strains did not. The sensitivity of the amplification was about 10 cfu.With the aid of the rDNA-PCR,23 of the 23 cerebrospinal fluids (CSF) specimens which had been confirmed C.neoforrnans positive by smear and/or culture were PCR-positive(100%),and 13 of the 14 CSF specimens which had been confirmed C.neoformans negative by smear and culture were PCR-negative (93%).The results of the present study suggest that rDNA-PCR is a sensitive and specific method for rapid diagnosis of cryptococcal meningitis.

Key words: Cryptococcal meningitis, PCR, rDNA