RESUMO
Cryptococcus isolates from Cuban patients were identified as C. neoformans var. grubii. Although this species has since long been associated with bird droppings, a recent genotyping study provided strong evidence for additional origins of exposure. We sampled different species of trees in Havana, Cuba to identify other potential sources of exposure to this fungus. A total of 662 samples were collected from 331 trees and cacti from Havana, Cuba. Initial selection of the isolates was carried out by conventional techniques. Isolates were further characterised using a combination of AFLP analysis and DNA sequence analysis. Identification by conventional methods yielded 121 C. neoformans and 61 C. gattii isolates. Molecular analyses showed that none of these isolates was C. gattii and only one isolate proved to be C. neoformans var. grubii. A total of 27 different other species were identified. The most prevalent species was C. heveanensis (33%). Sixty-five unidentifiable isolates segregated into ten potentially novel species. Conventional cultivation methods have a low specificity for C. neoformans complex and molecular analyses need to be applied to confirm identification of isolates from environmental sources. Environmental niches responsible for most of human cryptococcal infections in Cuba remain to be identified.
Assuntos
Cryptococcus/isolamento & purificação , Microbiologia Ambiental , Árvores/microbiologia , Análise do Polimorfismo de Comprimento de Fragmentos Amplificados , Criptococose/microbiologia , Cryptococcus/classificação , Cryptococcus/genética , Cuba , Humanos , FilogeniaAssuntos
Acinonyx/microbiologia , Criptococose/veterinária , Cryptococcus gattii/isolamento & purificação , Análise do Polimorfismo de Comprimento de Fragmentos Amplificados , Animais , Animais de Zoológico , Criptococose/microbiologia , Criptococose/patologia , Cryptococcus gattii/classificação , Cryptococcus gattii/genética , Cuba , DNA Fúngico/genética , Tipagem Molecular , Técnicas de Tipagem Micológica , RecidivaRESUMO
The genotypic diversity of Brazilian Cryptococcus neoformans strains was analyzed. The majority of the samples were alphaA (65%), followed by alphaB (17.5%), alphaD (9%), alphaAaD hybrids (5%), and alphaC (3.5%). A considerable genotypic diversity occurred within C. neoformans var. grubii, and a new amplified fragment length polymorphism genotype, 1B, was recognized.
Assuntos
Criptococose/diagnóstico , Cryptococcus neoformans/classificação , Cryptococcus neoformans/genética , Variação Genética , Filogenia , Polimorfismo Genético/genética , Animais , Sequência de Bases , Brasil , Columbidae/microbiologia , Criptococose/líquido cefalorraquidiano , Cryptococcus neoformans/isolamento & purificação , Primers do DNA , Fezes/microbiologia , Amplificação de Genes , Humanos , Reação em Cadeia da PolimeraseRESUMO
The genetic affiliation of a large number of isolates of the Cryptococcus neoformans species complex from environmental sources in Brazil has been investigated using amplified fragment length polymorphism (AFLP). The strains of C. neoformans isolated from a single tree, as well as from neighbouring trees, showed high similarity values (> 95%) of their AFLP patterns, thus suggesting considerable genetic homogeneity. The majority of isolates of C. neoformans belonged to AFLP genotype 1, and had serotype A and mating type alpha (= C. neoformans var. grubii). Three isolates belonged to AFLP genotype 2, with serotype D and mating type alpha (= C. neoformans var. neoformans). One isolate, obtained from a building in Rio de Janeiro inhabited by pigeons, belonged to the AD hybrid AFLP genotype 3. All isolates from trees of C. neoformans var. gattii (= C. gattii) belonged to AFLP genotype 6, and their banding patterns showed relatively low genetic homogeneity with a similarity value of about 76%. Isolates of this genotype occupy an environmental niche in the Americas, and they may cause disease in non-AIDS and AIDS patients as well.