IDENTIFICATION BY POLYMERASE CHAIN-REACTION FINGERPRINTING OF CRYPTOCOCCUS-NEOFORMANS SEROTYPE AD

Seventy-three Cryptococcus neoformans isolates and eight other yeast s trains were studied. Fingerprints produced by priming with (GACA)(4) d ifferentiated C. neoformans from all other yeasts tested and identifie d the five C. neoformans serotypes. Four major bands of molecular size 800, 540, 475 and 410 bp were recognized for serotypes A, AD and D. T wo of them were specific for serotype A and the other two for serotype D isolates. Serotype AD strains were identified by five different gen otypic patterns in which at least one of the two bands specific for se rotype A and D were present in different combinations. On repeated and simultaneously performed genotype and serotype testing of nine strain s, the genotypic pattern did not change, whereas serotyping was unstab le in three cases. PCR-fingerprinting using (GACA)(4) as a primer prov ed more stable than serology in discriminating among C. neoformans ser otypes A, D and AD and was able to distinguish among serotype AD strai ns.