RESUMO
The ribosomal RNA 5.8S is one of the four rRNAs that constitute ribosomes. In human cells, like in all eukaryotes, it derives from the extensive processing of a long precursor containing the sequence of 18S, 5.8S and 28S rRNAs. It has been confirmed also in human cells the presence of three isoforms of 5.8S rRNA: one more abundant called 5.8S short, one called 5.8S long bearing 5 extra-nucleotides at its 5' end and one 10 nucleotide shorter called 5.8S cropped. So far, little is known about 5.8S long specific role in cell biology and its function in human pathology. The lack of studies on the three 5.8S isoforms could be due to the techniques usually applied to study ribosome biogenesis, such as Northern blot with radioactively labelled probes, that require strict protective measures, and abundant and high-quality samples. To overcome this issue, we optimized a method that combines primer extension with a fluorescently labeled reverse primer designed on the 3' of 5.8S rRNA sequence and fragment analysis. The resulting electropherogram shows the peaks corresponding to the three isoforms of 5.8S rRNA. The estimation of the area underneath the peaks allows to directly quantify the isoforms and to express their relative abundance. The relative abundance of 5.8S long and 5.8S short remains constant using scalar dilution of RNA and in samples subjected to partial degradation. 5.8S cropped abundance varies significantly in lower concentrate RNA samples. This method allows to analyze rapidly and safely the abundance of 5.8S rRNA isoforms in samples that have been so far considered not suitable such as poorly concentrated samples, RNA derived from frozen tissue or unique samples.
Assuntos
RNA Ribossômico 5,8S/análise , Northern Blotting , Linhagem Celular , Células HeLa , Humanos , RNA , Isoformas de RNARESUMO
Tritrichomonas foetus is a causative agent of feline trichomonosis, resulting in large-bowel diarrhea in cats. Feline trichomonosis has been reported in the USA, Europe and some Asian countries but there is limited information for Thailand. This study investigated the prevalence of T. foetus infection in cats in the Bangkok metropolitan area and evaluated the in vitro efficacy of metronidazole (MDZ) and ronidazole (RDZ) against T. foetus Thai isolates. In total, 215 fecal samples were collected from 121 owned cats and 94 stray cats. All fecal samples were cultivated in InPouch™ TF-feline medium. Afterward, polymerase chain reaction (PCR) assays targeting the 5.8S rRNA gene, the ITS regions and DNA sequencing were used for the confirmation of T. foetus. The overall prevalence of T. foetus infection was 4.18% (9/215) based on cultivation and PCR. The sequencing results showed 100% homology to T. foetus sequences from GenBank. The average minimal lethal concentrations (MLCs) of MDZ were 333.33 and 66.67 µg/ml at 24 and 48 h, respectively. The average MLCs of RDZ were 29.16 and 12.5 µg/ml at 24 and 48 h, respectively. The MLC of the MDZ results revealed that T. foetus Thai isolates had a tendency to be MDZ-resistant. To the best of the authors' knowledge, this study was the first using in vitro cultivation and molecular techniques to report and confirm the presence of T. foetus in cats living in the Bangkok metropolitan area. Further studies are needed to determine the genuine infection rate of T. foetus in a greater population sample and the infection status in cats with signs of diarrhea in Thailand.
Assuntos
Doenças do Gato/epidemiologia , Infecções Protozoárias em Animais/epidemiologia , Tritrichomonas foetus/efeitos dos fármacos , Tritrichomonas foetus/isolamento & purificação , Animais , Doenças do Gato/parasitologia , Gatos , Cidades , DNA de Protozoário/análise , Resistência a Medicamentos/genética , Técnicas In Vitro , Prevalência , Infecções Protozoárias em Animais/parasitologia , RNA Ribossômico 5,8S/análise , Tailândia/epidemiologiaRESUMO
Spoilage caused by yeasts is a constant, widespread problem in the beverage industry that can result in major economic losses. Fruit juices provide an environment that allows the proliferation of yeast. Some factories in South Africa are not equipped with laboratory facilities to identify spoilage yeasts and outsourcing becomes a prolonged process which obstructs corrective action planning. This study aimed to establish yeast diversity and apply a rapid method for preliminary identification of spoilage yeasts associated with a small-scale fruit juice bottling factory. Yeast population in the factory was determined by isolation from the production environment, process equipment and spoiled products. PCR-RFLP analysis targeting the 5.8S-ITS region and D1/D2 sequencing was used for identification. A total of 207 yeasts belonging to 10 different genera (Candida, Lodderomyces, Wickerhamomyces, Yarrowia, Zygosaccharomyces, Zygoascus, Cryptococcus, Filobasidium, Rhodotorula/Cystobasidium and Trichosporon) were isolated and identified from the production environment and processing equipment. Candida intermedia, C. parapsilosis and Lodderomyces elongisporus were widely distributed in the factory. Zygosaccharomyces bailii, Z. bisporus, Zygoascus hellenicus and Saccharomyces cerevisiae were isolated from the spoiled products. The data provided a yeast control panel that was used successfully to identify unknown yeasts in spoiled products from this factory using polymerase chain reaction-restriction length polymorphism (PCR-RFLP) comparative analysis.
Assuntos
Contaminação de Alimentos/análise , Sucos de Frutas e Vegetais/microbiologia , Reação em Cadeia da Polimerase/métodos , Polimorfismo de Fragmento de Restrição , Leveduras/classificação , Leveduras/isolamento & purificação , Biodiversidade , DNA Fúngico , Manipulação de Alimentos , Técnicas de Tipagem Micológica , RNA Ribossômico/análise , RNA Ribossômico/genética , RNA Ribossômico 5,8S/análise , RNA Ribossômico 5,8S/genética , Análise de Sequência , Leveduras/genética , Leveduras/crescimento & desenvolvimentoRESUMO
Platelets are anucleate and mostly ribosome-free cells within the bloodstream, derived from megakaryocytes within bone marrow and crucial for cessation of bleeding at sites of injury. Inherited thrombocytopenias are a group of disorders characterized by a low platelet count and are frequently associated with excessive bleeding. SLFN14 is one of the most recently discovered genes linked to inherited thrombocytopenia where several heterozygous missense mutations in SLFN14 were identified to cause defective megakaryocyte maturation and platelet dysfunction. Yet, SLFN14 was recently described as a ribosome-associated protein resulting in rRNA and ribosome-bound mRNA degradation in rabbit reticulocytes. To unveil the cellular function of SLFN14 and the link between SLFN14 and thrombocytopenia, we examined SLFN14 (WT/mutants) in in vitro models. Here, we show that all SLFN14 variants colocalize with ribosomes and mediate rRNA endonucleolytic degradation. Compared to SLFN14 WT, expression of mutants is dramatically reduced as a result of post-translational degradation due to partial misfolding of the protein. Moreover, all SLFN14 variants tend to form oligomers. These findings could explain the dominant negative effect of heterozygous mutation on SLFN14 expression in patients' platelets. Overall, we suggest that SLFN14 could be involved in ribosome degradation during platelet formation and maturation.
Assuntos
Endorribonucleases/genética , Endorribonucleases/metabolismo , RNA Ribossômico/metabolismo , Trombocitopenia/genética , Animais , Células Cultivadas , Células HEK293 , Humanos , Mutação de Sentido Incorreto , RNA Ribossômico 5,8S/análise , Coelhos , Ribossomos/química , Ribossomos/metabolismoRESUMO
Dunaliella, a commercially important chlorophyte, is globally distributed in saline habitats. Morphological species have not been definitively reconciled with phylogenetic analyses. Considerable genetic diversity continues to be discovered in new isolates, especially from soil and benthic habitats. Twenty-nine new isolates from Great Salt Lake, Utah, many from benthic or supralittoral habitats, were phylogenetically analyzed using ITS1+5.8S+ITS2 in comparison to a broad sampling of available sequences. A few new isolates align in one branch of a bifurcated monophyletic Dunaliella salina clade and several cluster within monophyletic D. viridis. Several others align with relatively few unnamed strains from other locations, comprising a diverse clade that may represent two or more new species. The overall Dunaliella clade is relatively robust, but the nearest outgroups are ambiguously placed with extremely long branches. About half of the isolates, all from benthic or supralittoral habitats, have been persistently sarcinoid in liquid media since isolation. This trait is spread across the Dunaliella phylogeny. The morphology of two sarcinoid strains was documented with light microscopy, revealing an extensive glycocalyx. Clumping behavior of unicellular and sarcinoid strains was unaffected by presence or absence of Mg2+ or Ca2+ , addition of lectin-inhibiting monosaccharides, or water-soluble factors from morphologically opposite strains. Results from this investigation have significantly expanded our current understanding of Dunaliella diversity, but it seems likely that much remains to be discovered with additional sampling.
Assuntos
Clorofíceas/classificação , Filogenia , Clorofíceas/genética , DNA Espaçador Ribossômico/análise , Lagos , RNA de Algas/análise , RNA de Plantas/análise , RNA Ribossômico 5,8S/análise , UtahRESUMO
The family Ceratocoryaceae includes the genera Ceratocorys, Protoceratium, and Schuettiella, whose phylogenetic relationships are poorly known. Here, the new non-yessotoxin-producing species of the genus Ceratocorys, Ceratocorys mariaovidiorum sp. nov., previously reported as the toxic Protoceratium reticulatum, is described from examinations by light and scanning electron microscopy, molecular phylogeny, and toxin analyses. The species description is made from culture samples of strains CCMP1740 and CCMP404 from USA waters. Ceratocorys mariaovidiorum is globular and has thick and strongly reticulated plates with one pore within each reticule, just like P. reticulatum, but the key difference between the two species is the presence of five precingular plates in C. mariaovidiorum instead of six as in P. reticulatum. The thecal plate formula is Po, 4', 0a, 5â³, 6c, ~7s, 5â´, 0p, 2''''. The apical pore plate is oval with a λ-shaped pore. The first apical plate is narrow with a ventral pore on the right anterior side; it contacts the apical pore plate and its contact with the anterior sulcal plate is slight or absent. The fourth precingular plate of other Gonyaulacales is absent. Ceratocorys mariaovidiorum may have small spines on the second antapical plate. A phylogenetic study based on internal transcribed spacer/5.8SrDNA supports the morphological classification of C. mariaovidiorum as a new species of Ceratocorys and in a different clade from P. reticulatum.
Assuntos
Dinoflagellida/classificação , Dinoflagellida/genética , DNA Espaçador Ribossômico/análise , Dinoflagellida/citologia , Dinoflagellida/ultraestrutura , Microscopia Eletrônica de Varredura , Filogenia , RNA de Algas/análise , RNA de Protozoário/análise , RNA Ribossômico 5,8S/análise , Estados UnidosRESUMO
The grape yeast biota from several wine-producing areas, with distinct soil types and grapevine training systems, was assessed on five islands of Azores Archipelago, and differences in yeast communities composition associated with the geographic origin of the grapes were explored. Fifty-seven grape samples belonging to the Vitis vinifera grapevine cultivars Verdelho dos Açores (Verdelho), Arinto da Terceira (Arinto) and Terrantez do Pico (Terrantez) were collected in two consecutive years and 40 spontaneous fermentations were achieved. A total of 1710 yeast isolates were obtained from freshly crushed grapes and 1200 from final stage of fermentations. Twenty-eight species were identified, Hanseniaspura uvarum, Pichia terricola and Metschnikowia pulcherrima being the three most representative species isolated. Candida carpophila was encountered for the first time as an inhabitant of grape or wine-associated environments. In both sampling years, a higher proportion of H. uvarum in fresh grapes from Verdelho cultivar was observed, in comparison with Arinto cultivar. Qualitatively significant differences were found among yeast communities from several locations on five islands of the Archipelago, particularly in locations with distinctive agro-ecological compositions. Our results are in agreement with the statement that grape-associated microbial biogeography is non-randomly associated with interactions of climate, soil, cultivar, and vine training systems in vineyard ecosystems. Our observations strongly support a possible linkage between grape yeast and wine typicality, reinforcing the statement that different viticultural terroirs harbor distinctive yeast biota, in particular in vineyards with very distinctive environmental conditions.
Assuntos
DNA Fúngico/análise , DNA Espaçador Ribossômico/análise , Ecossistema , RNA Ribossômico 5,8S/análise , Vitis/microbiologia , Vinho/microbiologia , Leveduras/classificação , Biodiversidade , DNA Fúngico/genética , DNA Espaçador Ribossômico/genética , Técnicas de Tipagem Micológica/métodos , RNA Ribossômico 5,8S/genética , Análise de Sequência de DNA/métodos , Leveduras/genética , Leveduras/isolamento & purificaçãoRESUMO
CONTEXT: Invasive fungal infections are an important cause of morbidity and mortality among immunocompromised patients. OBJECTIVE: To design and evaluate a multiplexed assay aimed at quantitative detection and differentiation of the 5 molds that are most commonly responsible for pulmonary infections. DESIGN: Using labeled primer polymerase chain reaction chemistry, an assay was designed to target the 5.8S and 28S ribosomal RNA genes of Aspergillus spp, Fusarium spp, Scedosporium spp, and members of the order Mucorales ( Rhizopus oryzae , Rhizopus microsporus, Cunninghamella bertholletiae, Mucor circinelloides, Lichtheimia corymbifera, and Rhizomucor pusillus). This assay was split into 2 multiplexed reactions and was evaluated using both samples seeded with purified nucleic acid from 42 well-characterized clinical fungal isolates and 105 archived samples (47 blood [45%], 42 bronchoalveolar lavage fluid [40%], and 16 tissue [15%]) collected from rabbit models of invasive pulmonary fungal infections. RESULTS: Assay detection sensitivity was less than 25 copies of the target sequence per reaction for Aspergillus spp, 5 copies for Fusarium spp and Scedosporium spp, and 10 copies for the Mucorales. The assay showed quantitative linearity from 5 × 10(1) to 5 × 10(5) copies of target sequence per reaction. Sensitivities and specificities for bronchoalveolar lavage fluid, tissue, and blood samples were 0.86 and 0.99, 0.60 and 1.00, and 0.46 and 1.00, respectively. CONCLUSIONS: Labeled primer polymerase chain reaction permits rapid, quantitative detection and differentiation of common agents of invasive fungal infection. The assay described herein shows promise for clinical implementation that may have a significant effect on the rapid diagnosis and treatment of patients' severe infections caused by these pulmonary fungal pathogens.
Assuntos
Pneumopatias Fúngicas/diagnóstico , Pneumopatias Fúngicas/microbiologia , Reação em Cadeia da Polimerase Multiplex/métodos , Reação em Cadeia da Polimerase em Tempo Real/métodos , Animais , Aspergillus/genética , Modelos Animais de Doenças , Feminino , Fusarium/genética , Genes Fúngicos , Humanos , Técnicas de Diagnóstico Molecular/métodos , Técnicas de Diagnóstico Molecular/estatística & dados numéricos , Mucorales/genética , Reação em Cadeia da Polimerase Multiplex/estatística & dados numéricos , Técnicas de Tipagem Micológica/métodos , Técnicas de Tipagem Micológica/estatística & dados numéricos , RNA Fúngico/análise , RNA Fúngico/genética , RNA Ribossômico 28S/análise , RNA Ribossômico 28S/genética , RNA Ribossômico 5,8S/análise , RNA Ribossômico 5,8S/genética , Coelhos , Reação em Cadeia da Polimerase em Tempo Real/estatística & dados numéricos , Scedosporium/genética , Sensibilidade e EspecificidadeRESUMO
The number of sequences from both formally described taxa and uncultured environmental DNA deposited in the International Nucleotide Sequence Databases has increased substantially over the last two decades. Although the majority of these sequences represent authentic gene copies, there is evidence of DNA artifacts in these databases as well. These include lab artifacts, such as PCR chimeras, and biological artifacts such as pseudogenes or other paralogous sequences. Sequences that fall in basal positions in phylogenetic trees and appear distant from known sequences are particularly suspect. Phylogenetic analyses suggest that a novel sequence type (NS1) found in two boreal forest soil clone libraries belongs to the fungal kingdom but does not fall unambiguously within any known phylum. We have evaluated this sequence type using an array of secondary-structure analyses. To our knowledge, such analyses have never been used on environmental ribosomal sequences. Ribosomal secondary structure was modeled for four rRNA loci (ITS1, 5.8S, ITS2, 5' LSU). These models were analyzed for the presence of conserved domains, conserved nucleotide motifs, and compensatory base changes. Minimal free energy (MFE) foldings and GC contents of sequences representing the major fungal clades, as well as NS1, were also compared. NS1 displays secondary rRNA structures consistent with other fungi and many, but not all, conserved nucleotide motifs found across eukaryotes. However, our analyses show that many other authentic sequences from basal fungi lack more of these conserved motifs than does NS1. Together our findings suggest that NS1 represents an authentic gene copy. The methods described here can be used on any rRNA-coding sequence, not just environmental fungal sequences. As new-generation sequencing methods that yield shorter sequences become more widely implemented, methods that evaluate sequence authenticity should also be more widely implemented. For fungi, the adjacent 5.8S and ITS2 loci should be prioritized. This region is not only suited to distinguishing between closely related species, but it is also more informative in terms of expected secondary structure.
Assuntos
Conformação de Ácido Nucleico , RNA Ribossômico/análise , Solo/análise , Árvores , Alaska , Composição de Bases , Teorema de Bayes , DNA Fúngico/análise , DNA Espaçador Ribossômico/genética , Bases de Dados Genéticas , Funções Verossimilhança , Modelos Genéticos , Modelos Moleculares , Filogenia , RNA Ribossômico 5,8S/análise , Análise de Sequência de DNARESUMO
Two recently described pathogenic Candida species, C. nivariensis and C. bracarensis, share many phenotypic characteristics with C. glabrata and are easily misidentified as such. The aim of this study was to determine the occurrence of these cryptic species in Italy. One thousand yeast isolates collected in 14 Italian regions and identified as C. glabrata by phenotypic and biochemical methods were included in this study: 928 were screened on CHROMagar and 72 were analysed by a multiplex PCR. None of these cryptic species was identified despite the nationwide distribution and the variety of biological origin of the isolates.
Assuntos
Candida/isolamento & purificação , Genes Fúngicos , RNA Fúngico/análise , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Candida/classificação , Candida/genética , Candidíase/sangue , Candidíase/microbiologia , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Recém-Nascido , Itália , Masculino , Pessoa de Meia-Idade , Técnicas de Tipagem Micológica , Fenótipo , RNA Fúngico/genética , RNA Ribossômico 5,8S/análise , Adulto JovemRESUMO
We developed a reference karyotype for B. vulgaris which is applicable to all beet cultivars and provides a consistent numbering of chromosomes and genetic linkage groups. Linkage groups of sugar beet were assigned to physical chromosome arms by FISH (fluorescent in situ hybridization) using a set of 18 genetically anchored BAC (bacterial artificial chromosome) markers. Genetic maps of sugar beet were correlated to chromosome arms, and North-South orientation of linkage groups was established. The FISH karyotype provides a technical platform for genome studies and can be applied for numbering and identification of chromosomes in related wild beet species. The discrimination of all nine chromosomes by BAC probes enabled the study of chromosome-specific distribution of the major repetitive components of sugar beet genome comprising pericentromeric, intercalary and subtelomeric satellites and 18S-5.8S-25S and 5S rRNA gene arrays. We developed a multicolor FISH procedure allowing the identification of all nine sugar beet chromosome pairs in a single hybridization using a pool of satellite DNA probes. Fiber-FISH was applied to analyse five chromosome arms in which the furthermost genetic marker of the linkage group was mapped adjacently to terminal repetitive sequences on pachytene chromosomes. Only on two arms telomere arrays and the markers are physically linked, hence these linkage groups can be considered as terminally closed making the further identification of distal informative markers difficult. The results support genetic mapping by marker localization, the anchoring of contigs and scaffolds for the annotation of the sugar beet genome sequence and the analysis of the chromosomal distribution patterns of major families of repetitive DNA.
Assuntos
Beta vulgaris/genética , Cromossomos de Plantas/genética , Ligação Genética , Genoma de Planta , Hibridização in Situ Fluorescente/métodos , Sequências de Repetição em Tandem , Cromossomos Artificiais Bacterianos/genética , Sondas de DNA/genética , DNA de Plantas/análise , DNA de Plantas/genética , DNA Satélite/análise , DNA Satélite/genética , Marcadores Genéticos , Cariótipo , Estágio Paquíteno , Mapeamento Físico do Cromossomo/métodos , RNA Ribossômico/análise , RNA Ribossômico/genética , RNA Ribossômico 18S/análise , RNA Ribossômico 18S/genética , RNA Ribossômico 5,8S/análise , RNA Ribossômico 5,8S/genética , Padrões de Referência , Telômero/genéticaRESUMO
To assess the position of Kuro-Koji molds in black Aspergillus, we performed sequence analysis of approximately 2500 nucleotides of partial gene fragments, such as histone 3, on a total of 57 Aspergillus strains, including Aspergillus kawachii NBRC 4308, 12 Kuro-Koji molds isolated from awamori breweries in Japan, Aspergillus niger ATCC 1015, and A. tubingensis ATCC10550. Sequence results showed that all black Aspergillus strains could be classified into 3 types, type N which includes A. niger ATCC 1015, type T which includes A. tubingensis ATCC 10550, and type L which includes A. kawachii NBRC 4308. Phylogenetic analysis showed these three types belong to different clusters. All 12 Kuro-Koji molds isolated from awamori breweries were classified as type L, thus we concluded type L represents the industrial Kuro-Koji molds. We found all type L strains lack the An15g07920 gene which is required for ochratoxin A biosynthesis in black Aspergillus. This sequence is present in the genome of A. niger CBS 513.88 and has homology to the polyketide synthase fragment of A. ochraceus which is involved in ochratoxin A biosynthesis. Based on the industrial importance and the safety of Kuro-Koji molds, we propose to classify the type L strains as Aspergillus luchuensis, as initially reported by Dr. Inui.
Assuntos
Aspergillus/classificação , Microbiologia Industrial , Aspergillus/genética , Aspergillus/isolamento & purificação , Aspergillus/metabolismo , Aspergillus niger/classificação , Aspergillus niger/genética , DNA Fúngico/análise , DNA Fúngico/genética , Humanos , Microbiologia Industrial/métodos , Microbiologia Industrial/normas , Japão , Ocratoxinas/biossíntese , Filogenia , RNA Ribossômico 5,8S/análise , RNA Ribossômico 5,8S/genéticaRESUMO
Two new species of Cladorrhinum, C. flexuosum and C. microsclerotigenum, are described and their sequences of the 5.8S and 28S ribosomal DNA and internal transcribed spacers 1 and 2 of the ribosomal RNA gene cluster analyzed. Cladorrhinum flexuosum, isolated from soil in Spain, forms fast-growing, dull yellow colonies, flexuous conidiophores and globose to dacryoid conidia. Cladorrhinum microsclerotigenum, isolated from Musa sp. in Turkey, strongly resembles Cladorrhinum phialophoroides in the production of abundant terminal phialides, ellipsoid conidia and microsclerotia in culture. It differs from C. phialophoroides in its ability to grow at 36 C and high number of intercalary phialides, which only infrequently occur in C. phialophoroides.
Assuntos
Sordariales/classificação , DNA Fúngico/análise , DNA Espaçador Ribossômico/análise , Dados de Sequência Molecular , Filogenia , RNA Ribossômico 28S/análise , RNA Ribossômico 5,8S/análise , Análise de Sequência de DNA , Sordariales/genética , Sordariales/ultraestrutura , Esporos Fúngicos/citologia , Esporos Fúngicos/fisiologiaRESUMO
Having more information on the yeast ecology of grapes is important for wine-makers to produce wine with high quality and typical attributes. China is a significant wine-consuming country and is becoming a serious wine-producer, but little has been reported about the yeast ecology of local ecosystems. This study provides the first step towards the exploitation of the yeast wealth in China's vine-growing regions. The aim of this study was to investigate the yeast population density and diversity on three grape varieties cultivated in four representative vine-growing regions of China. Yeast species diversity was evaluated by using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and sequence analysis of the 5.8S internal transcribed spacer (ITS) ribosomal DNA (rDNA) region of cultivable yeasts. The grapes harbored yeast populations at 10(2)-10(6)CFU/mL, consisting mostly of non-Saccharomyces species. Seventeen different yeast species belonging to eight genera were detected on the grape samples tested, including Hanseniaspora uvarum, Cryptococcus flavescens, Pichia fermentans, Candida zemplinina, Cryptococcus carnescens, Candida inconpicua, Zygosaccharomyces fermentati, Issatchenkia terricola, Candida quercitrusa, Hanseniaspora guilliermondii, Candida bombi, Zygosaccharomyces bailii, Sporidiobolus pararoseus, Cryptococcus magnus, Metschnikowia pulcherrima, Issatchenkia orientalis and Pichia guilliermondii. H. uvarum and C. flavescens were the dominant species present on the grapes. For the first time Sporidiobolus pararoseus was discovered as an inhabitant of the grape ecosystem. The yeast community on grape berries was influenced by the grape chemical composition, vine-variety and vine-growing region. This study is the first to identify the yeast communities associated with grapes in China using molecular methods. The results enrich our knowledge of wine-related microorganisms, and can be used to promote the development of the local wine industry.
Assuntos
DNA Fúngico/análise , Filogenia , Vitis/microbiologia , Vinho/microbiologia , Leveduras/classificação , China , DNA Espaçador Ribossômico/análise , Microbiologia Ambiental , Microbiologia de Alimentos , Microbiologia Industrial , Técnicas de Tipagem Micológica , Polimorfismo de Fragmento de Restrição , Densidade Demográfica , RNA Ribossômico 5,8S/análise , Análise de Sequência de DNA , Especificidade da Espécie , Leveduras/isolamento & purificaçãoRESUMO
During the course of investigation on pythiaceous fungi occurring in the Burgundian vineyards, a new species of Pythium has been isolated. This oomycete is characterized by its nonproliferating and nonsporulating, spherical to cylindrical type of sporangia (hyphal bodies) germinating through germ tubes, smooth-walled oogonia that are supplied with hypogynous, monoclinous or rarely diclinous antheridia, and smooth-walled oospores. The antheridial cells are very prominent and are reminiscent of Pythium bifurcatum, Pythium segnitium and Pythium longandrum described previously by the author. The internal transcribed spacer region of the rRNA of this new species is composed of 883 bases, which is quite different from that of the closest relatives. Morphological and molecular features of this new species, named as Pythium burgundicum, are discussed in this article.
Assuntos
Pythium/isolamento & purificação , Microbiologia do Solo , Agricultura , Sequência de Bases , DNA Fúngico/análise , DNA Fúngico/genética , DNA Espaçador Ribossômico/análise , DNA Espaçador Ribossômico/genética , França , Hifas/citologia , Dados de Sequência Molecular , Filogenia , Pythium/classificação , Pythium/fisiologia , RNA Ribossômico 5,8S/análise , RNA Ribossômico 5,8S/genética , Alinhamento de Sequência , Análise de Sequência de DNA , Especificidade da Espécie , VinhoRESUMO
The natural Saccharomyces and non-Saccharomyces yeast flora present on the grape berries significantly affect wine production. Six grape varieties, Bangalore blue, Zinfandel, Cabernet, Chenin Blanc, Sauvignon Blanc and Shiraz are being used in India for wine making. The yeast diversity was studied on the basis of morphological, colony, physiological characteristics and 5.8S-ITS sequencing of rDNA of the isolates. Eleven different species belonging to seven genera were identified as: Candida azyma, Candida quercitrusa, Debaryomyces hansenii, Hanseniaspora guilliermondii, Hanseniaspora viniae, Hanseniaspora uvarum, Issatchenkia orientalis, Issatchenkia terricola, Pichia membranifaciens, Saccharomyces cerevisiae and Zygoascus steatolyticus. H. guilliermondii was the predominant species while S. cerevisiae was observed occasionally in the six vine varieties. For the first time, C. azyma was isolated from Bangalore blue and Cabernet varieties grown in different localities. This association may be attributed to the change in cropping pattern from sugarcane to viticulture in the vine growing regions and the known association of C. azyma with sugarcane phylloplane. Further analysis of the indigenous strains and the qualitative and quantitative changes in the flora during fermentation will be useful to understand wine quality and to design preservation strategies to control wine spoilage.
Assuntos
Filogenia , Vitis/classificação , Vitis/microbiologia , Vinho/microbiologia , Leveduras/classificação , Leveduras/fisiologia , DNA Fúngico/análise , DNA Espaçador Ribossômico/análise , Fermentação , Índia , Microbiologia Industrial , Dados de Sequência Molecular , Técnicas de Tipagem Micológica , RNA Ribossômico 5,8S/análise , Análise de Sequência de DNA , Especificidade da EspécieRESUMO
The genus Pythium is important in agriculture, since it contains many plant pathogenic species, as well as species that can promote plant growth and some that have biocontrol potential. In South Africa, very little is known about the diversity of Pythium species within agricultural soil, irrigation and hydroponic systems. Therefore, the aim of the study was to characterise a selection of 85 Pythium isolates collected in South Africa from 1991 through to 2007. The isolates were characterised morphologically as well as through sequence and phylogenetic analyses of the internal transcribed spacer regions (ITS) and the 5.8S gene of the nuclear ribosomal DNA. Phylogenetic analyses showed that the isolates represented ten of the 11 published Pythium clades [Lévesque & De Cock, 2004. Molecular phylogeny and taxonomy of the genus Pythium. Mycological Research 108: 1363-1383]. Characterisation of isolates in clade D and J suggested that the phylogenetic concept of Pythium acanthicum and Pythium perplexum respectively, needs further investigation in order to enable reliable species identification within these clades. Our phylogenetic analyses of Pythium species in clade B also showed that species with globose sporangia group basal within this clade, and are not dispersed within the clade as previously reported. The 85 South African isolates represented 34 known species, of which 20 species have not been reported previously in South Africa. Additionally, three isolates (PPRI 8428, 8300 and 8418) were identified that may each represent putative new species, Pythium sp. WJB-1 to WJB-3.
Assuntos
Filogenia , Pythium/genética , Biodiversidade , DNA de Algas/genética , DNA de Algas/isolamento & purificação , DNA Espaçador Ribossômico/análise , DNA Espaçador Ribossômico/genética , Variação Genética , Doenças das Plantas/microbiologia , Pythium/citologia , Pythium/isolamento & purificação , RNA Ribossômico 5,8S/análise , RNA Ribossômico 5,8S/genética , Análise de Sequência de DNA , África do Sul , Especificidade da EspécieRESUMO
Truffles are one of the most valuable edible fungi and have drawn extensive research interests worldwide. In Taiwan, two species of truffle, Tuber formosanum and Tuber furfuraceum, have been identified and reported. Although the morphological features of these two truffles have been described, lack of molecular identification has led to difficulties with firmly establishing their relatedness to other truffles. In this study, we utilized the internal transcribed spacer (ITS) and beta-tubulin gene sequences to generate the phylogenetic relationship of T. formosanum and T. furfuraceum with other taxonomic relatives. Our analysis revealed five/three major phylogenetic clades according to the 5.8S-ITS2/beta-tubulin gene sequences and corroborated with their morphological characterization. Tuber formosanum highly resembles the Tuber indicum B complex, while T. furfuraceum is most similar to Tuber huidongense. Based on a molecular clock, we estimated that T. furfuraceum and T. formosanum would have diverged from their close relatives in mainland China between 10.2 and 4.1 Ma, respectively. Based on the results, we propose that these two Tuber species found in Taiwan might originate from the common ancestors with some truffle species in China. However, due to a long divergence time and geographical separation, they have evolved into indigenous species of Taiwan.
Assuntos
Ascomicetos/classificação , Ascomicetos/genética , Filogenia , Ascomicetos/ultraestrutura , China , DNA Fúngico/isolamento & purificação , DNA Espaçador Ribossômico/análise , DNA Espaçador Ribossômico/genética , Evolução Molecular , Dados de Sequência Molecular , Micorrizas/ultraestrutura , RNA Ribossômico 5,8S/análise , RNA Ribossômico 5,8S/genética , Alinhamento de Sequência , Análise de Sequência de DNA , Esporos/ultraestrutura , Taiwan , Tubulina (Proteína)/análise , Tubulina (Proteína)/genéticaRESUMO
In the present report, we describe the first case of a phaeohyphomycotic brain abscess in a 5-year-old boy with chronic granulomatous disease (CGD) admitted to hospital with seizures. A computed tomography (CT) scan revealed a cerebral abscess and the microbiology study showed a dark, melanin-pigmented fungus, exhibiting only sterile hyphae. This fungus was identified by the amplification and sequencing of the 5.8S RNA gene and of the adjacent internal transcriber spacer domains, ITS1 and ITS2, as Alternaria infectoria. Due to the impossibility of a surgical excision, and although several therapeutic strategies were attempted, the patient died. Limitations in the routine identification procedures and therapeutic options of this emerging opportunistic agent are highlighted in this report.
Assuntos
Alternaria/isolamento & purificação , Abscesso Encefálico/diagnóstico , Doença Granulomatosa Crônica/complicações , Micoses/diagnóstico , Alternaria/citologia , Alternaria/genética , Antifúngicos/uso terapêutico , Encéfalo/diagnóstico por imagem , Encéfalo/microbiologia , Abscesso Encefálico/tratamento farmacológico , Abscesso Encefálico/etiologia , Abscesso Encefálico/microbiologia , Caspofungina , Pré-Escolar , Equinocandinas/uso terapêutico , Evolução Fatal , Humanos , Lipopeptídeos , Masculino , Micoses/tratamento farmacológico , Micoses/etiologia , Micoses/microbiologia , Pirimidinas/uso terapêutico , RNA Fúngico/análise , RNA Ribossômico 5,8S/análise , Radiografia , Convulsões , Triazóis/uso terapêutico , VoriconazolRESUMO
The aim of this study was to identify and characterise the predominant yeasts in Champús, a traditional Colombian cereal-based beverage with a low alcoholic content. Samples of Champús from 20 production sites in the Cauca Valley region were analysed. A total of 235 yeast isolates were identified by conventional microbiological analyses and by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) of ITS1-5.8S rDNA-ITS2. The dominant species were: Saccharomyces cerevisiae, Issatchenkia orientalis, Pichia fermentans, Pichia kluyveri var. kluyveri, Zygosaccharomyces fermentati, Torulospora delbruekii, Galactomyces geotrichum and Hanseniaspora spp. Model Champús systems were inoculated with single strains of some isolated sporogenus species and the aromatic profiles were analysed by SPME. Analysis of data showed that Champús strains produced high amounts of esters. The aromatic compounds produced by Saccharomyces and non-Saccharomyces yeasts from Champús can exert a relevant influence on the sensory characteristics of the fermented beverage. The Champús strains could thus represent an important source for new yeast biotypes with potential industrial applications.