RESUMO
The novel HLA-DPB1*14:01:15 allele differs from DPB1*14:01:01:01 by change of C > T in exon 3.
Assuntos
Alelos , Sequência de Bases , Éxons , Cadeias beta de HLA-DP , Teste de Histocompatibilidade , Doadores de Tecidos , Humanos , Cadeias beta de HLA-DP/genética , Brasil , Análise de Sequência de DNA/métodos , Medula Óssea , Alinhamento de Sequência , Códon , Transplante de Medula ÓsseaRESUMO
HLA-DQB1*02:211 allele differs from DQB1*02:02:01:02 by change of C â A in exon 2.
Assuntos
Alelos , Éxons , Cadeias beta de HLA-DQ , Doadores de Tecidos , Humanos , Cadeias beta de HLA-DQ/genética , Brasil , Teste de Histocompatibilidade , Transplante de Medula Óssea , Sequência de Bases , Análise de Sequência de DNA/métodos , Códon , Medula ÓsseaRESUMO
The new HLA-DRB3*03:69 allele differs from DRB3*03:01:01:03 by change of C â G in exon 3.
Assuntos
Alelos , Éxons , Cadeias HLA-DRB3 , Sequenciamento de Nucleotídeos em Larga Escala , Teste de Histocompatibilidade , Humanos , Sequência de Bases , Códon , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Teste de Histocompatibilidade/métodos , Cadeias HLA-DRB3/genética , Alinhamento de Sequência , Análise de Sequência de DNA/métodosRESUMO
The new HLA-DPA1*01:182 allele differs from HLA-DPA1*01:03:01:04 by a single mismatch in exon 4.
Assuntos
Medula Óssea , Cadeias alfa de HLA-DP , Humanos , Alelos , Brasil , Teste de HistocompatibilidadeRESUMO
We identified two new HLA-DRB3 alleles in Brazilian individuals using next generation sequencing.
Assuntos
Medula Óssea , Humanos , Cadeias HLA-DRB3 , Alelos , BrasilRESUMO
HLA-A*68:190:02 differs from A*68:190:01 by a single synonymous nucleotide change in exon 2.
Assuntos
Medula Óssea , Humanos , Alelos , Brasil , Éxons/genéticaRESUMO
Four new HLA-B alleles were identified in Brazilian individuals using next generation sequencing.
Assuntos
Medula Óssea , Doadores de Tecidos , Humanos , Brasil , Alelos , Transplante de Medula Óssea , Sequenciamento de Nucleotídeos em Larga Escala , Antígenos HLA-B/genéticaRESUMO
The occurrence of black aspergilli in onions has been reported as frequent, and this group of fungi harbors potentially toxigenic species. In addition, Aspergillus niger has been reported as the causative agent of black mold rot, an important postharvest disease that causes damage throughout the world. Brazil stands out as one of the world's largest onion producers. However, few studies have been conducted to investigate the mycobiota in Brazilian onions. For this reason, we investigated the mycobiota of 48 market (n = 25) and field (n = 23) onion bulb samples. Nineteen soil samples were collected from the same fields and evaluated. In field onions and soil samples, Penicillium spp. was the prevalent fungal group, whereas in market samples A. section Nigri was the most frequent group. Due to the taxonomic complexity of this group, species identification was supported by phylogenetic data (CaM gene). A. welwitschiae was the most prevalent species in market samples. Black aspergillus strains were evaluated for fumonisin B2 (FB2) and ochratoxin A (OTA) production. Overall, 53% and 2.2% of the strains produced FB2 and OTA, respectively. The occurrence of FB2 and OTA was also investigated in onion bulb samples but none showed contamination with these mycotoxins.
Assuntos
Aspergillus/isolamento & purificação , Microbiologia de Alimentos , Cebolas/microbiologia , Microbiologia do Solo , Aspergillus/classificação , Aspergillus/genética , Aspergillus/metabolismo , Brasil , Humanos , Micobioma/genética , Micotoxinas/análise , Micotoxinas/metabolismo , Cebolas/química , Penicillium/classificação , Penicillium/genética , Penicillium/isolamento & purificação , FilogeniaRESUMO
The aim of this study was to isolate Aspergillus section Nigri from onion samples bought in supermarkets and to analyze the fungal isolates by means of molecular data in order to differentiate A. niger and A. welwitschiae species from the other non-toxigenic species of black aspergilli, and detect genes involved in the biosynthesis of ochratoxin A and fumonisin B2. Aspergillus section Nigri were found in 98% (94/96) of the onion samples. Based on the results of multiplex PCR (performed on 500 randomly selected strains), 97.4% of the Aspergillus section Nigri strains were recognized as A. niger/A. welwitschiae. Around half of them were subjected to partial sequencing of the CaM gene to distinguish one from the other. A total of 97.9% of the isolates were identified as A. welwitschiae and only 2.1% as A. niger. The fum8 gene, involved in fumonisin B2 biosynthesis, was found in 36% of A. welwitschiae isolates, but radH and pks genes, involved in ochratoxin A biosynthesis, were found in only 2.8%. The presence/absence of fum8 gene in the A. welwitschiae genome is closely associated with ability/inability of the isolates to produce fumonisin in vitro. Based on these results, we suggest that in-depth studies are conducted to investigate the presence of fumonisins in onion bulbs.
Assuntos
Aspergillus niger/genética , Microbiologia de Alimentos , Genoma Bacteriano , Micotoxinas/metabolismo , Cebolas/microbiologia , Aspergillus niger/classificação , Aspergillus niger/isolamento & purificação , Vias Biossintéticas/fisiologia , Contaminação de Alimentos/análise , Fumonisinas/metabolismo , Micotoxinas/classificação , Ocratoxinas/biossíntese , Filogenia , PrevalênciaRESUMO
The garlic contains sulfur bioactive compounds responsible for medicinal properties. The decrease of these compounds due to inadequate storage conditions reduces the beneficial properties and favors infection by microorganisms. Several studies have shown high frequency of garlic infected with Aspergillus section Nigri that potentially produce mycotoxin. Garlic samples were collected in markets of Brazil and a total of 32 samples (of 36) had the fungal infection with predominant genus Aspergillus (50.3%), Penicillium (34.7%), and Fusarium (11%). A total of 63% (649/1031) of infection with Aspergillus section Nigri, of which 60 isolates were selected for analysis of genetic variability that resulted in 4 clusters. Representatives of clusters were identified by the calmodulin gene. Isolates from cluster I were subdivided into A-I and identified as A. niger (16 isolates) and the isolates of clusters B-I, II, and III were identified as A. welwitschiae (43 isolates). Besides, an isolate of the IV-cluster was identified by A. luchuensis. Further, we used the multiplex PCR to verify genotypes of 59 isolates, and none of these had OTA production-associated genotype. Moreover, 19 A. welwitschiae and 15 A. niger were FB2 production-associated genotype. Our study is the first report to the incidence of garlic infection in Brazil and to show that A. welwitschiae causes most of these infections.
Assuntos
Aspergillus , Fumonisinas/metabolismo , Alho/microbiologia , Ocratoxinas/metabolismo , Aspergillus/genética , Aspergillus/metabolismo , Aspergillus/patogenicidade , Brasil , Microbiologia de Alimentos , GenótipoRESUMO
The presence of Aspergillus section Flavi and aflatoxins in sugarcane as well as in by-products, such as molasses, sugar, yeast cream and dried yeast, collected from different fields and processing plants in São Paulo state, were investigated throughout the sugarcane production chain. A total of 246 samples was collected and analyzed and 226 isolates of Aspergillus section Flavi were isolated. Aspergillus section Flavi strains were found in sugarcane juice, milled sugarcane, stalk, soil and dried yeast samples. Among the isolates of Aspergillus section Flavi submitted to polyphasic identification (nâ¯=â¯57), Aspergillus novoparasiticus and Aspergillus arachidicola were predominantly found. A significant proportion of the isolates (84.5%) were found to have morphological and physiological characteristics of A. novoparasiticus. Most samples, with the exception of sugar, showed some aflatoxin contamination. The highest level was in dried yeast with an average of 2.55⯵g/kg and maximum value of 10.19⯵g/kg. This is the first report of contamination of sugarcane by A. novoparasiticus.
Assuntos
Aflatoxinas/análise , Aspergillus/isolamento & purificação , Contaminação de Alimentos/análise , Saccharum/microbiologia , Aspergillus/classificação , Microbiologia de Alimentos , Microbiologia do SoloRESUMO
This study investigated the presence of Aspergillus species belonging to Aspergillus section Nigri on Vitis labrusca and its hybrid grapes grown in Brazil. The ability of the fungi isolates to produce ochratoxin A (OTA) and fumonisin B2 (FB2) as well as the presence of these mycotoxins in the grapes were also studied. Eighty-eight samples were collected from the main grape producing states in Brazil: Rio Grande do Sul (n=30), Pernambuco (n=21), São Paulo (n=21) and Paraná (n=16). The highest average contamination level by A. section Nigri occurred on the grapes from Pernambuco (66.3%). A total of 2042 A. section Nigri isolates was analyzed and clustered in three groups according to morphology characterization: A. section Nigri uniseriate (79.3%), A. niger "aggregate" (18.3%) and A. carbonarius (2.4%). In order to precisely identify the Aspergillus species, two hundred and forty-eight strains were subjected to DNA sequencing. Among the A. section Nigri uniseriate group, the following species were found: A. japonicus, A. uvarum, A. brunneoviolaceus, A. aculeatus and A. labruscus. Within the A. niger "aggregate", the following species were found: A.niger sensu stricto, A. welwitschiae and A. vadensis. Regarding mycotoxin-production capacity, 3.2% of the total A. section Nigri isolates (2042) were positive for OTA production and from A. niger "aggregate" (373) tested, 42.1% were FB2 producers. However, none of the 88 grape samples were contaminated with these mycotoxins.
Assuntos
Aspergillus/isolamento & purificação , Contaminação de Alimentos/análise , Fumonisinas/análise , Micotoxinas/análise , Ocratoxinas/análise , Vitis/microbiologia , Aspergillus/classificação , Aspergillus/genética , Brasil , Microbiologia de Alimentos/métodos , Micotoxinas/biossíntese , Ocratoxinas/biossínteseRESUMO
Maize is one of the most important commercial crops cultivated throughout the world, mostly in tropical and subtropical countries. It is highly susceptible to mycotoxins, toxic secondary metabolites produced by fungi. In this study, we assessed freshly harvested corn produced in Brazil for aflatoxin contamination and the presence of Aspergillus. B type aflatoxins (AFB1+AFB2) were detected in 56% of 16 grain samples, while G type aflatoxins (AFG1+AFG2) were detected in 25%. Of the total number of grains (n=1920) evaluated for the presence of fungi species, 4.7% were infected with Aspergillus species, 74.5% and 16.7% respectively with Fusarium and Penicillium species and 4.1% with other fungi genera. In total, 89 Aspergillus isolates were identified, most (86 isolates) characterized as belonging to Aspergillus section Flavi, and the remainder to Aspergillus section Cremei (2 isolates) and Aspergillus section Terrei (1 isolate). All the isolates of section Flavi were subjected to molecular analysis. They were found to belong to six species, including Aspergillus novoparasiticus, Aspergillus arachidicola and Aspergillus pseudocaelatus, all aflatoxins B and G producing species, which are herein described for the first time infecting corn kernels.
Assuntos
Aflatoxina B1/análise , Aflatoxinas/análise , Aspergillus flavus/isolamento & purificação , Aspergillus flavus/metabolismo , Fusarium/isolamento & purificação , Penicillium/isolamento & purificação , Zea mays/microbiologia , Análise do Polimorfismo de Comprimento de Fragmentos Amplificados , Aspergillus flavus/patogenicidade , Sequência de Bases , Brasil , DNA Fúngico/genética , Análise de Sequência de DNA , Tubulina (Proteína)/genéticaRESUMO
We present the multiplex PCR data for the presence/absence of genes involved in OTA and FB2 biosynthesis in Aspergillus niger/Aspergillus welwitschiae strains isolated from different food substrates in Brazil. Among the 175 strains analyzed, four mPCR profiles were found: Profile 1 (17%) highlights strains harboring in their genome the pks, radH and the fum8 genes. Profile 2 (3.5%) highlights strains harboring genes involved in OTA biosynthesis i.e. radH and pks. Profile 3 (51.5%) highlights strains harboring the fum8 gene. Profile 4 (28%) highlights strains not carrying the genes studied herein. This research content is supplemental to our original research article, "Prospecting for the incidence of genes involved in ochratoxin and fumonisin biosynthesis in Brazilian strains of A. niger and A. welwitschiae" [1].
RESUMO
Aspergillus niger "aggregate" is an informal taxonomic rank that represents a group of species from the section Nigri. Among A. niger "aggregate" species Aspergillus niger sensu stricto and its cryptic species Aspergillus welwitschiae (=Aspergillus awamori sensu Perrone) are proven as ochratoxin A and fumonisin B2 producing species. A. niger has been frequently found in tropical and subtropical foods. A. welwitschiae is a new species, which was recently dismembered from the A. niger taxon. These species are morphologically very similar and molecular data are indispensable for their identification. A total of 175 Brazilian isolates previously identified as A. niger collected from dried fruits, Brazil nuts, coffee beans, grapes, cocoa and onions were investigated in this study. Based on partial calmodulin gene sequences about one-half of our isolates were identified as A. welwitschiae. This new species was the predominant species in onions analyzed in Brazil. A. niger and A. welwitschiae differ in their ability to produce ochratoxin A and fumonisin B2. Among A. niger isolates, approximately 32% were OTA producers, but in contrast only 1% of the A. welwitschiae isolates revealed the ability to produce ochratoxin A. Regarding fumonisin B2 production, there was a higher frequency of FB2 producing isolates in A. niger (74%) compared to A. welwitschiae (34%). Because not all A. niger and A. welwitschiae strains produce ochratoxin A and fumonisin B2, in this study a multiplex PCR was developed for detecting the presence of essential genes involved in ochratoxin (polyketide synthase and radHflavin-dependent halogenase) and fumonisin (α-oxoamine synthase) biosynthesis in the genome of A. niger and A. welwitschiae isolates. The frequency of strains harboring the mycotoxin genes was markedly different between A. niger and A. welwitschiae. All OTA producing isolates of A. niger and A. welwitschiae showed in their genome the pks and radH genes, and 95.2% of the nonproducing isolates did not contain these genes. The α-oxoamine synthase gene was detected in 100% and 36% of the A. niger and A. welwitschiae isolates, respectively. The loss of ochratoxin A production in A. niger and A. welwitschiae is highly associated with gene deletions within the ochratoxin biosynthetic gene cluster. The loss of fumonisin production in A. welwitschiae is associated with gene deletions within the fumonisin biosynthetic gene cluster, but this is not the case with A. niger.
Assuntos
Aspergillus/genética , Microbiologia de Alimentos , Fumonisinas , Ocratoxinas , Aspergillus/isolamento & purificação , Aspergillus/metabolismo , Aspergillus niger/genética , Aspergillus niger/metabolismo , Brasil , Família Multigênica/genética , Reação em Cadeia da Polimerase Multiplex , Ocratoxinas/biossínteseRESUMO
We designed a primer pair (BtubNomF/BtubNomR) specifically for amplifying Aspergillus nomius DNA. In vitro assays confirmed BtubNomF/BtubNomR specificity, corroborating its usefulness in detecting and identifying A. nomius. We then investigated the occurrence of A. nomius in floral visitors of Bertholletia excelsa trees by means of PCR, and A. nomius was detected in the following bees: Xylocopa frontalis, Bombus transversalis, Centris denudans, C. ferruginea, and Epicharis flava. The presence of A. nomius in bees visiting Brazil nuts opens up new avenues for obtaining novel insights into the process whereby Brazil nuts are contaminated by aflatoxin-producing fungi.
Assuntos
Aspergillus/isolamento & purificação , Abelhas/microbiologia , Bertholletia/microbiologia , Flores/microbiologia , Animais , Aspergillus/genética , Abelhas/fisiologia , BrasilRESUMO
The exploitation of the Brazil nut is one of the most important activities of the extractive communities of the Amazon rainforest. However, its commercialization can be affected by the presence of aflatoxins produced by fungi, namely Aspergillus section Flavi. In the present study, we investigated a collection of Aspergillus nomius strains isolated from Brazil nuts using different approaches, including morphological characters, RAPD and AFLP profiles, partial ß-tubulin and calmodulin nucleotide sequences, aflatoxin patterns, as well as tolerance to low water activity in cultured media. Results showed that most of the isolates do belong to A. nomius species, but a few were re-identified as Aspergillus pseudonomius, a very recently described species. The results of the analyses of molecular variance, as well as the high pairwise FST values between A. nomius and A. pseudonomius suggested the isolation between these two species and the inexistence of gene flow. Fixed interspecific nucleotide polymorphisms at ß-tubulin and calmodulin loci are presented. All A. pseudonomius strains analyzed produced aflatoxins AFB1, AFB2, AFG1 and AFG2. This study contains the first-ever report on the occurrence in Brazil nuts of A. pseudonomius. The G-type aflatoxins and the mycotoxin tenuazonic acid are reported here for the first time in A. pseudonomius.
Assuntos
Aspergillus/fisiologia , Bertholletia/microbiologia , Microbiologia de Alimentos , Aflatoxinas/isolamento & purificação , Aspergillus/genética , Aspergillus/isolamento & purificação , Variação Genética , Ácido Tenuazônico/isolamento & purificaçãoRESUMO
Approximately 70 % of Aspergillus westerdijkiae strains are able to produce ochratoxin A (OTA), a nephrotoxic and carcinogenic mycotoxin which have been found in cereal and food commodities. Despite of its importance there is, up to now, no information available about which genes are differentially expressed between A. westerdijkiae ochratoxin-producing and non-producing strains. Using cDNA RDA approach we successfully sequenced 231 raw ESTs expected to be enriched in the ochratoxin-producing strain. BLASTX searches against the public databases showed that of these, 205 ESTs (79 %) exhibited significant similarities with proteins of known functions, 28 ESTs (11 %) had matches to hypothetical proteins, and the remaining 27 ESTs (10 %) had no significant hits. EST alignment resulted in a total of 14 non-redundant consensus sequences. Three putative genes encoding oxidoreductases were validated as up-expressed in the OTA producer strain using RT-qPCR approach. The expression of the putative genes encoding a cytochrome P450 family protein, 3-hydroxyphenylacetate-6-hydroxylase, and endoplasmic reticulum oxidoreductin were higher (32-, 2.8- and 20-fold respectively) in the OTA producer strain compared to the non-producer strain.