RESUMEN
Two independent surveys of yeasts associated with different bromeliads in different Brazilian regions led to the proposal of a novel yeast species, Bullera vrieseae sp. nov., belonging to the Tremellales clade (Agaricomycotina, Basidiomycota). Analysis of the sequences in the internal transcribed spacer (ITS) region and D1/D2 domain of the LSU rRNA gene suggested affinity to a phylogenetic lineage that includes Bullera miyagiana and Bullera sakaeratica. Six isolates of the novel species were obtained from different bromeliads and regions in Brazil. Sequence analysis of the D1/D2 domains of the large subunit of the rRNA gene showed that the novel species differs from B. miyagiana and B. sakaeratica by 85 and 64ânt substitutions, respectively and by more than 75ânt substitutions in the ITS region. Phenotypically, Bullera vrieseae sp. nov. can be distinguished from both species based on the assimilation of meso-erythritol, which was negative for B. vrieseae sp. nov. but positive for the others, assimilation of d-glucosamine, which was positive for B. vrieseae sp. nov. but negative for B. miyagiana and of l-sorbose, which was negative for B. vrieseae sp. nov. but positive for B. sakaeratica. The novel species Bullera vrieseae sp. nov. is proposed to accommodate these isolates. The type strain of Bullera vrieseae sp. nov. is UFMG-CM-Y379T (BRO443T; ex-type CBS 13870T).
Asunto(s)
Basidiomycota/clasificación , Bromeliaceae/microbiología , Filogenia , Basidiomycota/genética , Basidiomycota/aislamiento & purificación , Brasil , ADN de Hongos/genética , ADN Espaciador Ribosómico/genética , Datos de Secuencia Molecular , Técnicas de Tipificación Micológica , Análisis de Secuencia de ADNRESUMEN
Several independent surveys of yeasts associated with different plant materials and soil led to the proposal of a novel yeast species belonging to the Tremellales clade (Agaricomycotina, Basidiomycota). Analysis of the sequences of the D1/D2 domains and internal transcribed spacer region of the large subunit of the rRNA gene suggested affinity to a phylogenetic lineage that includes Hannaella coprosmaensis, Hannaella oryzae and Hannaella sinensis. Thirty-two isolates were obtained from different sources, including bromeliads, nectar of Heliconia psittacorum (Heliconiaceae), flowers of Pimenta dioica (Myrtaceae), roots and leaves of sugar cane (Saccharum spp.) in Brazil, leaves of Cratoxylum maingayi, Arundinaria pusilla and Vitis vinifera in Thailand, soil samples in Taiwan, and prairie soil in the USA. Sequence analysis of the D1/D2 domains of the large subunit of the rRNA gene showed that the novel species differs from Hannaella coprosmaensis and Hannaella oryzae by 36 and 46 nt substitutions, respectively. A novel species is suggested to accommodate these isolates, for which the name Hannaella pagnoccae sp. nov. is proposed. The type strain is BI118(T) (â=âCBS 11142(T)â=âATCC MYA-4530(T)).
Asunto(s)
Basidiomycota/clasificación , Heliconiaceae/microbiología , Myrtaceae/microbiología , Filogenia , Saccharum/microbiología , Microbiología del Suelo , Secuencia de Bases , Basidiomycota/genética , Basidiomycota/aislamiento & purificación , ADN de Hongos/genética , ADN Espaciador Ribosómico/genética , Flores/microbiología , Datos de Secuencia Molecular , Técnicas de Tipificación Micológica , Hojas de la Planta/microbiología , Raíces de Plantas/microbiología , Análisis de Secuencia de ADN , TaiwánRESUMEN
We have screened BRCA2 c.156_157insAlu founder mutation in a cohort of 168 women with diagnosis of breast cancer referred for genetic counseling because of risk of being carriers of hereditary breast and ovarian cancer syndrome. Portuguese founder mutation BRCA2 c.156_157insAlu was identified in three unrelated breast cancer probands. Genotyping identified a common haplotype between markers D13S260 and D13S171, and allele sizes were compatible to those described in the Portuguese families. Allele sizes of marker D13S1246, however, were concordant in two families, suggesting that the haplotype may be larger in a subset of families. Tumor phenotypes in Brazilian families seem to reinforce the high prevalence of breast cancer among affected males. However, an apparent excess of gastrointestinal and tongue neoplasias were also observed in these families. Although these tumors are not part of the phenotypic spectrum of hereditary breast and ovarian cancer syndrome, they might be accounted for by other risk alleles contained in the founder haplotype region.
Asunto(s)
Proteína BRCA2/genética , Neoplasias de la Mama/complicaciones , Efecto Fundador , Neoplasias Gastrointestinales/etiología , Mutación de Línea Germinal/genética , Neoplasias Ováricas/complicaciones , Neoplasias de la Lengua/etiología , Adulto , Anciano , Proteína BRCA1/genética , Secuencia de Bases , Brasil/epidemiología , Neoplasias de la Mama/epidemiología , Neoplasias de la Mama/genética , ADN/análisis , ADN/genética , Femenino , Neoplasias Gastrointestinales/epidemiología , Predisposición Genética a la Enfermedad , Pruebas Genéticas , Heterocigoto , Humanos , Persona de Mediana Edad , Datos de Secuencia Molecular , Neoplasias Ováricas/epidemiología , Neoplasias Ováricas/genética , Linaje , Fenotipo , Reacción en Cadena de la Polimerasa , Pronóstico , Neoplasias de la Lengua/epidemiologíaRESUMEN
Two novel yeast species, Candida aechmeae sp. nov. and Candida vrieseae sp. nov., were isolated from bromeliads in Itapuã Park, Rio Grande do Sul, Brazil. These species are genetically isolated from all other currently recognized ascomycetous yeasts based on their sequence divergence in the D1/D2 domain of the LSU rRNA gene. C. aechmeae sp. nov. is phylogenetically close to Candida ubatubensis, a species also isolated from bromeliads in Brazil, but the novel species can be differentiated on the basis of differences in the D1/D2 domain and positive results for the assimilation of l-arabinose, raffinose, inulin and citrate. Candida vrieseae sp. nov. is phylogenetically placed in a clade near Candida membranifaciens that is composed of several species associated with insects, but the novel species can be differentiated from them by the D1/D2 and ITS gene sequences, positive results for the assimilation of nitrite and a negative result for the assimilation of ethylamine. The type strain for Candida aechmeae sp. nov. is BI153(T) (=CBS 10831(T)=NRRL Y-48456(T)) and the type strain for C. vrieseae sp. nov. is BI146(T) (=CBS 10829(T)=NRRL Y-48461(T)).
Asunto(s)
Bromelia/microbiología , Candida/clasificación , Candida/aislamiento & purificación , Brasil , Candida/genética , Candida/metabolismo , ADN de Hongos/genética , ADN Ribosómico/genética , Datos de Secuencia Molecular , Filogenia , ARN Ribosómico 16S/genéticaRESUMEN
The Heteroduplex Mobility Assay (HMA) method using the PCR amplified D1/D2 region of the 26S rDNA was tested for the differentiation of clinically relevant Candida species. Strains belonging to the same species are not expected to form heteroduplexes in this assay when their PCR products are mixed. D1/D2 HMA experiments between all Candida type strains tested showed heteroduplex formation, including Candida albicans and Candida dubliniensis. There was no heteroduplex formation when most clinical and non-type strains were tested against the type strain of their presumptive species, except when C. albicans WVE and C. dubliniensis TAI were analysed. Additional HMA experiments, phenotypic characterisation, and D1/D2 sequencing identified these isolates as Candida tropicalis and Candida parapsilosis, respectively. HMA provides a rapid and relatively simple molecular tool for the differentiation of potentially pathogenic Candida species.
Asunto(s)
Candida/clasificación , Candida/genética , ADN de Hongos/genética , ADN Ribosómico/genética , Análisis Heterodúplex/métodos , Secuencia de Bases , Candida/aislamiento & purificación , Candida albicans/clasificación , Candida albicans/genética , Candida albicans/aislamiento & purificación , Candida tropicalis/clasificación , Candida tropicalis/genética , Candida tropicalis/aislamiento & purificación , Cartilla de ADN/genética , ADN de Hongos/aislamiento & purificación , ADN Ribosómico/aislamiento & purificación , Humanos , ARN de Hongos/genética , ARN Ribosómico/genética , Especificidad de la EspecieRESUMEN
Two killer yeast strains (HB55 and HB88) capable of inhibiting human pathogenic fungi were isolated from leaves of Hibiscus rosa-sinensis in Brazil. These isolates were identified by conventional methods and sequencing of the D1/D2 region of the 26S rDNA as Kodamaea ohmeri. They inhibited all Cryptococcus neoformans (vars. neoformans, grubii and gattii) strains tested, including reference, clinical and environmental isolates. The killer phenotype was not cured by thermal treatment.
Asunto(s)
Antibiosis , Cryptococcus neoformans/crecimiento & desarrollo , Saccharomycetales/crecimiento & desarrollo , Brasil , ADN de Hongos/química , ADN de Hongos/genética , ADN Ribosómico/química , ADN Ribosómico/genética , Microbiología Ambiental , Hibiscus/microbiología , Técnicas de Tipificación Micológica , Hojas de la Planta/microbiología , ARN Ribosómico/genética , Saccharomycetales/clasificación , Saccharomycetales/aislamiento & purificación , Análisis de Secuencia de ADNRESUMEN
The internal transcribed spacer (ITS) region of rDNA was used for taxonomic inferences in ascomycetous yeasts. The Debaryomyces species had a 640-690 ITS size. The analyzed Candida species can be differentiated by its distinct ITS size. The enzymatic digestion of the ITS region show large homogeneity in Debaryomyces, with polymorphism for only two enzymes. The ITS size and the enzymatic restriction method were used in Brazilian isolates, detecting some Debaryomyces misidentifications in cultures previously identified by conventional methods.