RESUMO
Conventional breeding efforts for iron (Fe) and zinc (Zn) biofortification of bread wheat (Triticum aestivum L.) have been hindered by a lack of genetic variation for these traits and a negative correlation between grain Fe and Zn concentrations and yield. We have employed genetic engineering to constitutively express (CE) the rice (Oryza sativa) nicotianamine synthase 2 (OsNAS2) gene and upregulate biosynthesis of two metal chelators - nicotianamine (NA) and 2'-deoxymugineic acid (DMA) - in bread wheat, resulting in increased Fe and Zn concentrations in wholemeal and white flour. Here we describe multi-location confined field trial (CFT) evaluation of a low-copy transgenic CE-OsNAS2 wheat event (CE-1) over 3 years and demonstrate higher concentrations of NA, DMA, Fe, and Zn in CE-1 wholemeal flour, white flour, and white bread and higher Fe bioavailability in CE-1 white flour relative to a null segregant (NS) control. Multi-environment models of agronomic and grain nutrition traits revealed a negative correlation between grain yield and grain Fe, Zn, and total protein concentrations, yet no correlation between grain yield and grain NA and DMA concentrations. White flour Fe bioavailability was positively correlated with white flour NA concentration, suggesting that NA-chelated Fe should be targeted in wheat Fe biofortification efforts.
Assuntos
Oryza , Triticum , Ácido Azetidinocarboxílico/análogos & derivados , Pão/análise , Grão Comestível/metabolismo , Farinha/análise , Oryza/genética , Oryza/metabolismo , Melhoramento Vegetal , Triticum/genética , Triticum/metabolismo , Zinco/metabolismoRESUMO
Our systematic review assessed the impact of botanical fermented food (BFF) consumption on glucose, lipid, anthropometric, inflammatory and gut microbiota parameters, in adults with metabolic syndrome (MetS), MetS components or type 2 diabetes mellitus (T2DM). Embase, MEDLINE, Cochrane CENTRAL and Google Scholar were searched with no language limits, from inception to 31 August 2022, for eligible randomised controlled trials (RCTs). Two independent reviewers screened 6873 abstracts and extracted relevant data. Risk of bias (ROB) was assessed using the Cochrane Collaboration's ROB2 tool. The final review included twenty-six RCTs, with thirty-one reports published between 2001 and 2022. Significant (p < 0·05) within-group and between-group changes in cardiometabolic outcome means were reported in twenty-three and nineteen studies, respectively. Gut microbiota composition was assessed in four studies, with two finding significant between-group differences. No significant difference between groups of any measured outcomes was observed in five studies. There were fourteen studies at low ROB; ten were of some concern; and two were at high ROB. In 73% of included studies, BFF consumption by participants with obesity, MetS or T2DM led to significant between-group improvements in discrete cardiometabolic outcomes, including fasting blood glucose, lipid profile, blood pressure, waist circumference, body fat percentage and C-reactive protein. BFF consumption increased the abundance of beneficial gut bacteria, such as Bifidobacterium and LAB, whilst reducing potential pathogens such as Bacteroides. To determine the clinical significance of BFFs as therapeutic dietary adjuncts, their safety, tolerability and affordability must be balanced with the limited power and magnitude of these preliminary findings.
RESUMO
Sparkling wine is an alcoholic beverage enjoyed around the world. The sensory properties of sparkling wine depend on a complex interplay between the chemical and biochemical components in the final product. Glycoproteins have been linked to positive and negative qualities in sparkling wine, but the glycosylation profiles of sparkling wine have not been previously investigated in detail. We analyzed the glycoproteome of sparkling wines using protein- and glycopeptide-centric approaches. We developed an automated workflow that created ion libraries to analyze sequential window acquisition of all theoretical mass spectra data-independent acquisition mass spectrometry data based on glycopeptides identified by Byonic (Protein Metrics; version 2.13.17). We applied our workflow to three pairs of experimental sparkling wines to assess the effects of aging on lees and of different yeast strains used in the liqueur de tirage for secondary fermentation. We found that aging a cuvée on lees for 24 months compared with 8 months led to a dramatic decrease in overall protein abundance and an enrichment in large glycans at specific sites in some proteins. Secondary fermentation of a Riesling wine with Saccharomyces cerevisiae yeast strain Siha4 produced more yeast proteins and glycoproteins than with S. cerevisiae yeast strain DV10. The abundance and glycosylation profiles of grape glycoproteins were also different between grape varieties. To our knowledge, this work represents the first in-depth study into protein- and peptide-specific glycosylation in sparkling wines and describes a quantitative glycoproteomic sequential window acquisition of all theoretical mass spectra/data-independent acquisition workflow that is broadly applicable to other sample types.
Assuntos
Proteínas Fúngicas/análise , Glicopeptídeos/análise , Glicoproteínas/análise , Proteínas de Plantas/análise , Saccharomyces cerevisiae , Vitis/química , Vinho/análise , Fermentação , Proteínas Fúngicas/metabolismo , Glicopeptídeos/metabolismo , Glicoproteínas/metabolismo , Glicosilação , Proteínas de Plantas/metabolismo , Polissacarídeos/metabolismo , Proteômica , Saccharomyces cerevisiae/metabolismoRESUMO
We investigated the effects of (poly)phenol-rich sugarcane extract (PRSE), sugarcane fibre (SCFiber), and the combination of them (PRSE + SCFiber) on the gut microbiota and short-chain fatty acids (SCFA) production using in vitro digestion and pig faecal fermentation. Measuring total phenolic content and antioxidant activity through the in vitro digestion stages showed that PRSE + SCFiber increased the delivery of (poly)phenols to the in vitro colonic fermentation stage compared to PRSE alone. The PRSE + SCFiber modulated the faecal microbiota profile by enhancing the relative abundances of Prevotella, Lactobacillus, and Blautia, and reducing the relative abundance of Streptococcus. PRSE + SCFiber also mitigated the inhibitory effects of PRSE on SCFA production. These results suggest that the inclusion of sugarcane fibre with PRSE could increase the availability of phenolic compounds in the colon and modulate the gut microbiota towards a more favourable profile.
Assuntos
Fibras na Dieta , Fezes , Microbioma Gastrointestinal , Saccharum , Animais , Fibras na Dieta/administração & dosagem , Fibras na Dieta/análise , Fibras na Dieta/metabolismo , Digestão , Grão Comestível/química , Ácidos Graxos Voláteis/biossíntese , Fezes/química , Fezes/microbiologia , Fermentação , Suínos , Polifenóis/farmacologia , Extratos Vegetais/farmacologia , Microbioma Gastrointestinal/fisiologiaRESUMO
Microbial ecology and activity in wine production influences grapevine health and productivity, conversion of sugar to ethanol during fermentation, wine aroma, wine quality and distinctiveness. Fungi in the vineyard ecosystem are not well described. Here, we characterized the spatial and temporal dynamics of fungal communities associated with the grapevine (grapes, flowers, leaves, and roots) and soils over an annual growth cycle in two vineyards to investigate the influences of grape habitat, plant developmental stage (flowering, fruit set, veraison, and harvest), vineyards, and climatic conditions. Fungi were influenced by both the grapevine habitat and plant development stage. The core microbiome was prioritized over space and time, and the identified core members drove seasonal community succession. The developmental stage of veraison, where the grapes undergo a dramatic change in metabolism and start accumulating sugar, coincided with a distinct shift in fungal communities. Co-occurrence networks showed strong correlations between the plant microbiome, the soil microbiome, and weather indices. Our study describes the complex ecological dynamics that occur in microbial assemblages over a growing season and highlight succession of the core community in vineyards.
Assuntos
Fungos/fisiologia , Micobioma , Vitis , Vinho , Fungos/classificação , Vitis/microbiologiaRESUMO
Angiotensin-I-converting enzyme (ACE) inhibitory peptides are able to inhibit the activity of ACE, which is the key enzymatic factor mediating systemic hypertension. ACE-inhibitory peptides can be obtained from edible proteins and have the function of antihypertension. The amino acid sequences and the secondary structures of ACE-inhibitory peptides determine the inhibitory activities and stability. The resistance of ACE-inhibitory peptides to digestive enzymes and peptidase affect their antihypertensive bioactivity in vivo. In this paper, the mechanism of ACE-inhibition, sources of the inhibitory peptides, structure-activity relationships, stability during digestion, absorption and transportation of ACE-inhibitory peptides, and consumption of ACE-inhibitory peptides are reviewed, which provide guidance to the development of new functional foods and production of antihypertensive nutraceuticals and pharmaceuticals.
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Inibidores da Enzima Conversora de Angiotensina , Peptidil Dipeptidase A , Angiotensinas , Disponibilidade Biológica , Peptídeos , Peptidil Dipeptidase A/metabolismoRESUMO
Grapes are an important global horticultural product, and are mainly used for winemaking. Typically, grapes and wines are rich in various phytochemicals, including phenolics, terpenes, pyrazines, and benzenoids, with different compounds responsible for different nutritional and sensory properties. Among these compounds, sesquiterpenes, a subcategory of the terpenes, are attracting increasing interest as they affect aroma and have potential health benefits. The characteristics of sesquiterpenes in grapes and wines in terms of classification, biosynthesis pathway, and active functions have not been extensively reviewed. This paper summarizes 97 different sesquiterpenes reported in grapes and wines and reviews their biosynthesis pathways and relevant bio-regulation mechanisms. This review further discusses the functionalities of these sesquiterpenes including their aroma contribution to grapes and wines and potential health benefits, as well as how winemaking processes affect sesquiterpene concentrations.
Assuntos
Sesquiterpenos/química , Vitis/química , Vinho/análise , Fermentação , Frutas/químicaRESUMO
The gut microbiota plays a prominent role in human health. Alterations in the gut microbiota are linked to the development of chronic diseases such as obesity, inflammatory bowel disease, metabolic syndrome, and certain cancers. We know that diet plays an important role to initiate, shape, and modulate the gut microbiota. Long-term dietary patterns are shown to be closely related with the gut microbiota enterotypes, specifically long-term consumption of carbohydrates (related to Prevotella abundance) or a diet rich in protein and animal fats (correlated to Bacteroides). Short-term consumption of solely animal- or plant-based diets have rapid and reproducible modulatory effects on the human gut microbiota. These alterations in microbiota profile by dietary alterations can be due to impact of different dietary macronutrients, carbohydrates, protein, and fat, which have diverse modulatory effects on gut microbial composition. Food-derived phenolics, which encompass structural variants of flavonoids, hydroxybenzoic acids, hydroxycinnamic acids, coumarins, stilbenes, ellagitannins, and lignans can modify the gut microbiota. Gut microbes have been shown to act on dietary fibers and phenolics to produce functional metabolites that contribute to gut health. Here, we discuss recent studies on the impacts of phenolics and phenolic fiber-rich foods on the human gut microbiota and provide an insight into potential synergistic roles between their bacterial metabolic products in the regulation of the intestinal microbiota.
Assuntos
Bactérias/metabolismo , Fibras na Dieta , Microbioma Gastrointestinal/fisiologia , Fenóis/química , Animais , Bactérias/classificação , HumanosRESUMO
OBJECTIVE: Human intestinal epithelial organoids (IEOs) are increasingly being recognised as a highly promising translational research tool. However, our understanding of their epigenetic molecular characteristics and behaviour in culture remains limited. DESIGN: We performed genome-wide DNA methylation and transcriptomic profiling of human IEOs derived from paediatric/adult and fetal small and large bowel as well as matching purified human gut epithelium. Furthermore, organoids were subjected to in vitro differentiation and genome editing using CRISPR/Cas9 technology. RESULTS: We discovered stable epigenetic signatures which define regional differences in gut epithelial function, including induction of segment-specific genes during cellular differentiation. Established DNA methylation profiles were independent of cellular environment since organoids retained their regional DNA methylation over prolonged culture periods. In contrast to paediatric and adult organoids, fetal gut-derived organoids showed distinct dynamic changes of DNA methylation and gene expression in culture, indicative of an in vitro maturation. By applying CRISPR/Cas9 genome editing to fetal organoids, we demonstrate that this process is partly regulated by TET1, an enzyme involved in the DNA demethylation process. Lastly, generating IEOs from a child diagnosed with gastric heterotopia revealed persistent and distinct disease-associated DNA methylation differences, highlighting the use of organoids as disease-specific research models. CONCLUSIONS: Our study demonstrates striking similarities of epigenetic signatures in mucosa-derived IEOs with matching primary epithelium. Moreover, these results suggest that intestinal stem cell-intrinsic DNA methylation patterns establish and maintain regional gut specification and are involved in early epithelial development and disease.
Assuntos
Metilação de DNA , Epigênese Genética , Células Epiteliais/metabolismo , Mucosa Intestinal/citologia , Mucosa Intestinal/metabolismo , Organoides/metabolismo , Transcriptoma , Diferenciação Celular , Células Cultivadas , Repetições Palindrômicas Curtas Agrupadas e Regularmente Espaçadas , HumanosRESUMO
BACKGROUND & AIMS: We analyzed DNA methylation patterns and transcriptomes of primary intestinal epithelial cells (IEC) of children newly diagnosed with inflammatory bowel diseases (IBD) to learn more about pathogenesis. METHODS: We obtained mucosal biopsies (N = 236) collected from terminal ileum and ascending and sigmoid colons of children (median age 13 years) newly diagnosed with IBD (43 with Crohn's disease [CD], 23 with ulcerative colitis [UC]), and 30 children without IBD (controls). Patients were recruited and managed at a hospital in the United Kingdom from 2013 through 2016. We also obtained biopsies collected at later stages from a subset of patients. IECs were purified and analyzed for genome-wide DNA methylation patterns and gene expression profiles. Adjacent microbiota were isolated from biopsies and analyzed by 16S gene sequencing. We generated intestinal organoid cultures from a subset of samples and genome-wide DNA methylation analysis was performed. RESULTS: We found gut segment-specific differences in DNA methylation and transcription profiles of IECs from children with IBD vs controls; some were independent of mucosal inflammation. Changes in gut microbiota between IBD and control groups were not as large and were difficult to assess because of large amounts of intra-individual variation. Only IECs from patients with CD had changes in DNA methylation and transcription patterns in terminal ileum epithelium, compared with controls. Colon epithelium from patients with CD and from patients with ulcerative colitis had distinct changes in DNA methylation and transcription patterns, compared with controls. In IECs from patients with IBD, changes in DNA methylation, compared with controls, were stable over time and were partially retained in ex-vivo organoid cultures. Statistical analyses of epithelial cell profiles allowed us to distinguish children with CD or UC from controls; profiles correlated with disease outcome parameters, such as the requirement for treatment with biologic agents. CONCLUSIONS: We identified specific changes in DNA methylation and transcriptome patterns in IECs from pediatric patients with IBD compared with controls. These data indicate that IECs undergo changes during IBD development and could be involved in pathogenesis. Further analyses of primary IECs from patients with IBD could improve our understanding of the large variations in disease progression and outcomes.
Assuntos
Colite Ulcerativa/genética , Colo Sigmoide/metabolismo , Doença de Crohn/genética , Metilação de DNA , Epigênese Genética , Células Epiteliais/metabolismo , Íleo/metabolismo , Mucosa Intestinal/metabolismo , Transcrição Gênica , Transcriptoma , Adolescente , Fatores Etários , Biópsia , Estudos de Casos e Controles , Colite Ulcerativa/diagnóstico , Colite Ulcerativa/microbiologia , Colo Sigmoide/microbiologia , Doença de Crohn/diagnóstico , Doença de Crohn/microbiologia , Diagnóstico Diferencial , Inglaterra , Células Epiteliais/microbiologia , Feminino , Microbioma Gastrointestinal , Perfilação da Expressão Gênica/métodos , Estudo de Associação Genômica Ampla , Humanos , Íleo/microbiologia , Mucosa Intestinal/microbiologia , Masculino , Organoides , Valor Preditivo dos Testes , Prognóstico , Estudos Prospectivos , Ribotipagem , Fatores de Tempo , Técnicas de Cultura de TecidosRESUMO
Streptococcus suis is one of the most important zoonotic bacterial pathogens of pigs, causing significant economic losses to the global swine industry. S. suis is also a very successful colonizer of mucosal surfaces, and commensal strains can be found in almost all pig populations worldwide, making detection of the S. suis species in asymptomatic carrier herds of little practical value in predicting the likelihood of future clinical relevance. The value of future molecular tools for surveillance and preventative health management lies in the detection of strains that genetically have increased potential to cause disease in presently healthy animals. Here we describe the use of genome-wide association studies to identify genetic markers associated with the observed clinical phenotypes (i) invasive disease and (ii) asymptomatic carriage on the palatine tonsils of pigs on UK farms. Subsequently, we designed a multiplex PCR to target three genetic markers that differentiated 115 S. suis isolates into disease-associated and non-disease-associated groups, that performed with a sensitivity of 0.91, a specificity of 0.79, a negative predictive value of 0.91, and a positive predictive value of 0.79 in comparison to observed clinical phenotypes. We describe evaluation of our pathotyping tool, using an out-of-sample collection of 50 previously uncharacterized S. suis isolates, in comparison to existing methods used to characterize and subtype S. suis isolates. In doing so, we show our pathotyping approach to be a competitive method to characterize S. suis isolates recovered from pigs on UK farms and one that can easily be updated to incorporate global strain collections.
Assuntos
Portador Sadio/veterinária , Infecções Estreptocócicas/veterinária , Streptococcus suis/isolamento & purificação , Streptococcus suis/patogenicidade , Doenças dos Suínos/microbiologia , Animais , Portador Sadio/microbiologia , Inglaterra , Marcadores Genéticos/genética , Genoma Bacteriano/genética , Técnicas de Diagnóstico Molecular , Reação em Cadeia da Polimerase Multiplex , Tonsila Palatina/microbiologia , Infecções Estreptocócicas/microbiologia , Streptococcus suis/genética , Suínos , Virulência/genética , País de GalesRESUMO
Quorum sensing is a well-described mechanism of intercellular signalling among bacteria, which involves cell-density-dependent chemical signal molecules. The concentration of these quorum-sensing molecules increases in proportion to cell density until a threshold value is exceeded, which triggers a community-wide response. In this review, we propose that intercellular signalling mechanisms can be associated with a corresponding ecological interaction type based on similarities between how the interaction affects the signal receiver and producer. Thus, we do not confine quorum sensing, a specific form of intercellular signalling, to only cooperative behaviours. Instead, we define it as cell-density-dependent responses that occur at a critical concentration of signal molecules and through a specific signalling pathway. For fungal species, the medically important yeast Candida albicans has a well-described quorum sensing system, while this system is not well described in Saccharomyces cerevisiae, which is involved in food and beverage fermentations. The more precise definition for quorum sensing proposed in this review is based on the studies suggesting that S. cerevisiae may undergo intercellular signalling through quorum sensing. Through this lens, we conclude that there is a lack of evidence to support a specific signalling mechanism and a critical signal concentration of these behaviours in S. cerevisiae, and, thus, these features require further investigation.
Assuntos
Interações Microbianas , Microbiota , Percepção de Quorum , Saccharomyces cerevisiae/fisiologia , Transdução de Sinais , Candida albicans/fisiologia , Saccharomyces cerevisiae/genéticaRESUMO
The visual properties of sparkling wine including foam and bubbles are an indicator of sparkling wine quality. Foam properties, particularly foam height (FH) and foam stability (TS), are significantly influenced by the chemical composition of the wine. This review investigates our current knowledge of specific chemical compounds and, the mechanisms by which they influence the foam properties of sparkling wines. Grape and yeast proteins, amino acids, polysaccharides, phenolic compounds, organic acids, fatty acids, ethanol and sugar are examined with respect to their contribution to foam characteristics in sparkling wines made with the Traditional, Transfer, and Charmat and carbonation methods. Contradictory results have been identified that appear to be due to the analytical methods used to measure and quantify compounds and foam. Biopolymer complexes are discussed and absent knowledge with regards to thaumatin-like proteins (TLPs), polysaccharides, amino acids, oak-derived phenolic compounds and organic acids are identified. Future research is also likely to concentrate on visual analysis of sparkling wines by in-depth imaging analysis and specific sensory analysis techniques.
Assuntos
Bebidas Gaseificadas/análise , Vinho/análise , Aminoácidos/análise , Dióxido de Carbono , Ácidos Graxos/análise , Fenóis/análise , Polissacarídeos/análise , Proteínas/análise , Saccharomyces cerevisiae/metabolismo , Vitis/químicaRESUMO
The disease course of children with ulcerative colitis (UC) varies substantially. Published data on predictors of disease outcomes in children remain scarce. We validate clinical predictors of outcomes in 93 children with UC in a single centre (age range: 2-18 years, minimum follow-up: 18 months). We stratified children into 3 groups according to their disease course, that is, 1â=âmild (38/93, 40.9%), 2â=âmoderate (38/93, 40.9%), 3â=âsevere (17, 18.2%). Comparison of clinical and biochemical parameters was performed between groups using Chi-square, Mann-Whitney, and log-rank tests. Predictors of a severe disease course included pancolitis (P 0.01), low albumin (P 0.005), low haemoglobin at diagnosis (P 0.04), paediatric ulcerative colitis activity index (PUCAI) at 3 months, and nonresponse to steroids at 3 months (P 0.0001). In our cohort, failure to achieve remission at 3 months implied an 80% likelihood to require biologics or major surgery within 18 months. A specific 3-month review point is recommended to guide future management.
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Colite Ulcerativa/tratamento farmacológico , Fármacos Gastrointestinais/uso terapêutico , Infliximab/uso terapêutico , Adolescente , Criança , Pré-Escolar , Colite Ulcerativa/patologia , Feminino , Fármacos Gastrointestinais/administração & dosagem , Humanos , Infliximab/administração & dosagem , Masculino , Prontuários Médicos , Prognóstico , Estudos Prospectivos , Indução de Remissão , Sensibilidade e Especificidade , Índice de Gravidade de Doença , Resultado do TratamentoRESUMO
BACKGROUND: Beer quality is mainly defined by its colour, foamability and foam stability, which are influenced by the chemical composition of the product such as proteins, carbohydrates, pH and alcohol. Traditional methods to assess specific chemical compounds are usually time-consuming and costly. This study used rapid methods to evaluate 15 foam and colour-related parameters using a robotic pourer (RoboBEER) and chemical fingerprinting using near infrared spectroscopy (NIR) from six replicates of 21 beers from three types of fermentation. Results from NIR were used to create partial least squares regression (PLS) and artificial neural networks (ANN) models to predict four chemometrics such as pH, alcohol, Brix and maximum volume of foam. RESULTS: The ANN method was able to create more accurate models (R2 = 0.95) compared to PLS. Principal components analysis using RoboBEER parameters and NIR overtones related to protein explained 67% of total data variability. Additionally, a sub-space discriminant model using the absorbance values from NIR wavelengths resulted in the successful classification of 85% of beers according to fermentation type. CONCLUSION: The method proposed showed to be a rapid system based on NIR spectroscopy and RoboBEER outputs of foamability that can be used to infer the quality, production method and chemical parameters of beer with minimal laboratory equipment. © 2017 Society of Chemical Industry.
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Cerveja/normas , Análise de Alimentos/métodos , Processamento de Imagem Assistida por Computador/instrumentação , Processamento de Imagem Assistida por Computador/métodos , Aprendizado de Máquina , Espectrofotometria Infravermelho/métodos , Algoritmos , Análise de Alimentos/instrumentaçãoRESUMO
Haemophilus parasuis is a diverse bacterial species that is found in the upper respiratory tracts of pigs and can also cause Glässer's disease and pneumonia. A previous pangenome study of H. parasuis identified 48 genes that were associated with clinical disease. Here, we describe the development of a generalized linear model (termed a pathotyping model) to predict the potential virulence of isolates of H. parasuis based on a subset of 10 genes from the pangenome. A multiplex PCR (mPCR) was constructed based on these genes, the results of which were entered into the pathotyping model to yield a prediction of virulence. This new diagnostic mPCR was tested on 143 field isolates of H. parasuis that had previously been whole-genome sequenced and a further 84 isolates from the United Kingdom from cases of H. parasuis-related disease in pigs collected between 2013 and 2014. The combination of the mPCR and the pathotyping model predicted the virulence of an isolate with 78% accuracy for the original isolate collection and 90% for the additional isolate collection, providing an overall accuracy of 83% (81% sensitivity and 93% specificity) compared with that of the "current standard" of detailed clinical metadata. This new pathotyping assay has the potential to aid surveillance and disease control in addition to serotyping data.
Assuntos
Infecções por Haemophilus/diagnóstico , Infecções por Haemophilus/veterinária , Haemophilus parasuis/genética , Haemophilus parasuis/patogenicidade , Técnicas de Diagnóstico Molecular/métodos , Doenças dos Suínos/diagnóstico , Animais , Genoma/genética , Infecções por Haemophilus/microbiologia , Haemophilus parasuis/isolamento & purificação , Reação em Cadeia da Polimerase Multiplex , Suínos , Doenças dos Suínos/microbiologia , Virulência/genéticaRESUMO
Haemophilus parasuis causes Glässer's disease and pneumonia in pigs. Indirect hemagglutination (IHA) is typically used to serotype this bacterium, distinguishing 15 serovars with some nontypeable isolates. The capsule loci of the 15 reference strains have been annotated, and significant genetic variation was identified between serovars, with the exception of serovars 5 and 12. A capsule locus and in silico serovar were identified for all but two nontypeable isolates in our collection of >200 isolates. Here, we describe the development of a multiplex PCR, based on variation within the capsule loci of the 15 serovars of H. parasuis, for rapid molecular serotyping. The multiplex PCR (mPCR) distinguished between all previously described serovars except 5 and 12, which were detected by the same pair of primers. The detection limit of the mPCR was 4.29 × 10(5) ng/µl bacterial genomic DNA, and high specificity was indicated by the absence of reactivity against closely related commensal Pasteurellaceae and other bacterial pathogens of pigs. A subset of 150 isolates from a previously sequenced H. parasuis collection was used to validate the mPCR with 100% accuracy compared to the in silico results. In addition, the two in silico-nontypeable isolates were typeable using the mPCR. A further 84 isolates were analyzed by mPCR and compared to the IHA serotyping results with 90% concordance (excluding those that were nontypeable by IHA). The mPCR was faster, more sensitive, and more specific than IHA, enabling the differentiation of 14 of the 15 serovars of H. parasuis.
Assuntos
Técnicas de Genotipagem/métodos , Haemophilus parasuis/classificação , Haemophilus parasuis/genética , Reação em Cadeia da Polimerase Multiplex/métodos , Sorotipagem/métodos , Animais , Cápsulas Bacterianas/genética , Loci Gênicos , Infecções por Haemophilus/diagnóstico , Infecções por Haemophilus/microbiologia , Infecções por Haemophilus/veterinária , Haemophilus parasuis/isolamento & purificação , Sensibilidade e Especificidade , Suínos , Doenças dos Suínos/diagnóstico , Doenças dos Suínos/microbiologia , Fatores de TempoRESUMO
Haemophilus parasuis is a common inhabitant of the upper respiratory tract of pigs, and the causative agent of Glässer's disease. This disease is characterized by polyserositis and arthritis, produced by the severe inflammation caused by the systemic spread of the bacterium. After an initial colonization of the upper respiratory tract, H. parasuis enters the lung during the early stages of pig infection. In order to study gene expression at this location, we sequenced the ex vivo and in vivo H. parasuis Nagasaki transcriptome in the lung using a metatranscriptomic approach. Comparison of gene expression under these conditions with that found in conventional plate culture showed generally reduced expression of genes associated with anabolic and catabolic pathways, coupled with up-regulation of membrane-related genes involved in carbon acquisition, iron binding and pathogenesis. Some of the up-regulated membrane genes, including ABC transporters, virulence-associated autotransporters (vtaAs) and several hypothetical proteins, were only present in virulent H. parasuis strains, highlighting their significance as markers of disease potential. Finally, the analysis also revealed the presence of numerous antisense transcripts with possible roles in gene regulation. In summary, this data sheds some light on the scarcely studied in vivo transcriptome of H. parasuis, revealing nutritional virulence as an adaptive strategy for host survival, besides induction of classical virulence factors.
Assuntos
Infecções por Haemophilus/veterinária , Haemophilus parasuis/genética , Haemophilus parasuis/patogenicidade , Pneumopatias/veterinária , Doenças dos Suínos/genética , Transcriptoma , Animais , Infecções por Haemophilus/genética , Infecções por Haemophilus/microbiologia , Haemophilus parasuis/metabolismo , Pneumopatias/genética , Pneumopatias/microbiologia , Análise de Sequência de DNA/veterinária , Suínos , Doenças dos Suínos/microbiologia , Regulação para Cima , Virulência , Fatores de VirulênciaRESUMO
BACKGROUND: Haemophilus parasuis is the etiologic agent of Glässer's disease in pigs and causes devastating losses to the farming industry. Whilst some hyper-virulent isolates have been described, the relationship between genetics and disease outcome has been only partially established. In particular, there is weak correlation between serovar and disease phenotype. We sequenced the genomes of 212 isolates of H. parasuis and have used this to describe the pan-genome and to correlate this with clinical and carrier status, as well as with serotype. RESULTS: Recombination and population structure analyses identified five groups with very high rates of recombination, separated into two clades of H. parasuis with no signs of recombination between them. We used genome-wide association methods including discriminant analysis of principal components (DAPC) and generalised linear modelling (glm) to look for genetic determinants of this population partition, serovar and pathogenicity. We were able to identify genes from the accessory genome that were significantly associated with phenotypes such as potential serovar specific genes including capsule genes, and 48 putative virulence factors that were significantly different between the clinical and non-clinical isolates. We also show that the presence of many previously suggested virulence factors is not an appropriate marker of virulence. CONCLUSIONS: These genes will inform the generation of new molecular diagnostics and vaccines, and refinement of existing typing schemes and show the importance of the accessory genome of a diverse species when investigating the relationship between genotypes and phenotypes.