CONCORDANCE OF CLINICAL AND ENVIRONMENTAL ISOLATES OF CRYPTOCOCCUS-NEOFORMANS VAR GATTII BY RANDOM AMPLIFICATION OF POLYMORPHIC DNA ANALYSIS AND PCR FINGERPRINTING

Sixty one clinical and forty-nine environmental isolates of Cryptococc us neoformans var. gattii from Australia and the United States were an alyzed by random amplification of polymorphic DNA (RAPD), using 12- to 22-mer primers in pairs, and/or PCR fingerprinting with a single prim er derived from the microsatellite core sequence of the wild-type phag e M13 (5' GAGGGTGGCGGTTCT 3'), Three major genetic profiles were ident ified by both typing techniques, A single RAPD profile (VGI) predomina ted among clinical isolates (44 of 48, 92%) and isolates from host euc alypts (45 of 45, 100%) from Australia, Of the 94 Australian isolates, 4 (3 clinical and 1 environmental) were assigned to profile VGII; 2 o f these were recovered from patients and one was recovered from plant debris from Western Australia, Only one Australian clinical isolate wa s assigned to profile VGIII, A different distribution of RAPD profiles (four VGIII, two VGII, and one VGI) was found among four clinical and three environmental isolates from the United States, RAPD profiles of 8 of the 101 isolates studied revealed minor genetic variants, 4 of p rofile VGI and 4 of profile VGII, Genetic concordance between the majo rity of clinical and environmental isolates in Australia is consistent with the hypothesis that human disease is acquired from exposure to h ost eucalypts, Profiles of clinical isolates were independent of body site of infection, and profiles of all isolates were stable over time. Analysis by PCR fingerprinting confirmed the RAPD results, A second R APD profile (VGII) was associated with infection in southwest Western Australia, where the two host eucalypts do not occur naturally, This r aises the possibility of an alternative and as yet unidentified natura l habitat of C. neoformans var. gattii. Our results indicate that RAPD analysis is a sensitive and useful method for investigating environme ntal sources of human infection with this biotype.