Hybrid genotypes in the pathogenic yeast Cryptococcus neoformans

• Published in: Microbiology (Society for General Microbiology) 2001-04, Vol.147 (4), p.891-907
• Main Authors: Boekhout, Teun, Theelen, Bart, Diaz, Mara, Fell, Jack W, Hop, Wim C. J, Abeln, Edwin C. A, Dromer, Francoise, Meyer, Wieland
• Format: Article
• Language: English
• Subjects: AIDS-Related Opportunistic Infections - microbiology; Animals; Biological and medical sciences; Cryptococcus - genetics; Cryptococcus neoformans; Cryptococcus neoformans - classification; Cryptococcus neoformans - genetics; Cryptococcus neoformans - isolation & purification; DNA, Fungal - analysis; Fundamental and applied biological sciences. Psychology; Genotype; Geography; Growth, nutrition, metabolism, transports, enzymes. Molecular biology; Host-Parasite Interactions; Humans; Microbiology; Mycology; Phenotype; Phylogeny; Polymerase Chain Reaction; Polymorphism, Genetic; Serotyping; Virulence
• ISSN: 1350-0872; 1465-2080
• DOI: 10.1099/00221287-147-4-891

Centraalbureau voor Schimmelcultures, Uppsalalaan 8, 3584 CT Utrecht, The Netherlands 1 Rosenstiel School of Marine and Atmospheric Sciences, University of Miami, 4600 Rickenbacker Causeway, Key Biscayne, FL 33149, USA 2 Department of Epidemiology & Biostatistics, Erasmus University Medical Centre, PO Box 1738, 3000 DR Rotterdam, The Netherlands 3 Institut Pasteur, Unité de Mycologie, Rue du Dr Roux, 75724 Paris Cedex 15, France 4 Molecular Mycology Laboratory, University of Sydney at Westmead Hospital, Westmead, NSW, Australia 5 Author for correspondence: Teun Boekhout. Tel: [phone]. Fax: [phone]. e-mail: boekhout{at}cbs.knaw.nl Amplified fragment length polymorphism (AFLP) genotyping of isolates of the pathogenic fungus Cryptococcus neoformans suggested a considerable genetic divergence between the varieties C. neoformans var. neoformans and C. neoformans var. grubii on the one hand versus C. neoformans var . gattii on the other. This divergence is supported by additional phenotypic, biochemical, clinical and molecular differences. Therefore, the authors propose the existence of two species, C. neoformans (Sanfelice) Vuillemin and C. bacillisporus Kwon-Chung, which differ in geographical distribution, serotypes and ecological origin. Within each species three AFLP genotypes occur, which differ in geographical distribution and serotypes. Differences in ecological origin (AIDS patients, non-AIDS patients, animals or the environment) were found to be statistically not significant. In C. neoformans as well as in C. bacillisporus one of the genotypes represented a hybrid. The occurrence of hybridization has consequences for the reproductive biology of the species, as new genotypes with altered virulence or susceptibility to antifungal drugs may arise through the exchange of genetic material. Keywords: Cryptococcus neoformans , systematics, hybrids, geography, serotypes, AFLP Abbreviations: AFLP, amplified fragment length polymorphism; CCV, cophenetic correlation value; CSF, cerebrospinal fluid; IGS, intergenic spacer; RAPD, random amplified polymorphic DNA; UPGMA, unweighted pair group method using arithmetic means