Heterogeneity of infection and extreme shedding patterns are common features of animal infectious diseases. Individual hosts that are super-shedders are key targets for control strategies. Nevertheless, the mechanisms associated with the emergence of super-shedders remain largely unknown. During chicken salmonellosis, a high heterogeneity of infection is observed when animal-to-animal cross-contaminations and reinfections are reduced. We hypothesized that unlike super-shedders, low-shedders would be able to block the first Salmonella colonization thanks to a different gut microbiota. The present study demonstrates that (i) axenic and antibiotic-treated chicks are more prone to become super-shedders; (ii) super or low-shedder phenotypes can be acquired through microbiota transfer; (iii) specific gut microbiota taxonomic features determine whether the chicks develop a low- and super-shedder phenotype after Salmonella infection in isolator; (iv) partial protection can be conferred by inoculation of four commensal bacteria prior to Salmonella infection. This study demonstrates the key role plays by gut microbiota composition in the heterogeneity of infection and pave the way for developing predictive biomarkers and protective probiotics.
- MeSH
- Escherichia coli O157 * MeSH
- fenotyp MeSH
- kur domácí MeSH
- Salmonella MeSH
- střevní mikroflóra * MeSH
- vylučování bakterií z těla MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Co-production of two or more desirable compounds from low-cost substrates by a single microbial catalyst could greatly improve the economic competitiveness of many biotechnological processes. However, reports demonstrating the adoption of such co-production strategy are still scarce. In this study, the ability of genome-edited strain Pseudomonas putida EM42 to simultaneously valorize d-xylose and d-cellobiose - two important lignocellulosic carbohydrates - by converting them into the platform chemical d-xylonate and medium-chain-length polyhydroxyalkanoates, respectively, was investigated. Biotransformation experiments performed with P. putida resting cells showed that promiscuous periplasmic glucose oxidation route can efficiently generate extracellular xylonate with a high yield. Xylose oxidation was subsequently coupled to the growth of P. putida with cytoplasmic β-glucosidase BglC from Thermobifida fusca on d-cellobiose. This disaccharide turned out to be a better co-substrate for xylose-to-xylonate biotransformation than monomeric glucose. This was because unlike glucose, cellobiose did not block oxidation of the pentose by periplasmic glucose dehydrogenase Gcd, but, similarly to glucose, it was a suitable substrate for polyhydroxyalkanoate formation in P. putida. Co-production of extracellular xylose-born xylonate and intracellular cellobiose-born medium-chain-length polyhydroxyalkanoates was established in proof-of-concept experiments with P. putida grown on the disaccharide. This study highlights the potential of P. putida EM42 as a microbial platform for the production of xylonate, identifies cellobiose as a new substrate for mcl-PHA production, and proposes a fresh strategy for the simultaneous valorization of xylose and cellobiose.
Cistus ladanifer scrublands, traditionally considered as unproductive, have nonetheless been observed to produce large quantities of king bolete (Boletus edulis) fruitbodies. These pyrophytic scrublands are prone to wildfires, which severely affect fungi, hence the need for fire prevention in producing C. ladanifer scrublands. In addition, B. edulis productions have severely decreased in the last years. A deeper understanding of the B. edulis life cycle and of biotic and abiotic factors influencing sporocarp formation is needed to implement management practices that facilitate B. edulis production. For example, some bacteria likely are involved in sporocarp production, representing a key part in the triple symbiosis (plant-fungus-bacteria). In this study, we used soil DNA metabarcoding in C. ladanifer scrublands to (i) assess the effect of site history and fire prevention treatment on bacterial richness and community composition; (ii) test if there was any correlation between various taxonomic groups of bacteria and mycelial biomass and sporocarp production of B. edulis; and to (iii) identify indicator bacteria associated with the most productive B. edulis sites. Our results show that site history drives bacterial richness and community composition, while fire prevention treatments have a weaker, but still detectable effect, particularly in the senescent plots. Sporocarp production correlated positively with genera in Verrucomicrobia. Several genera, e.g. Azospirillum and Gemmatimonas, were identified as indicators of the most productive sites, suggesting a potential biological role in B. edulis fructification. This study provides a better understanding of the triple symbiosis (plant-fungus-bacteria) involved in C. ladanifer-B. edulis systems.
- MeSH
- Bacteria klasifikace genetika MeSH
- Basidiomycota růst a vývoj MeSH
- Cistus růst a vývoj mikrobiologie MeSH
- metagenomika MeSH
- mikrobiální interakce MeSH
- mikrobiota * MeSH
- ničivé požáry prevence a kontrola MeSH
- půdní mikrobiologie * MeSH
- taxonomické DNA čárové kódování MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Plant secondary metabolism evolved in the context of highly organized and differentiated cells and tissues, featuring massive chemical complexity operating under tight environmental, developmental and genetic control. Biotechnological demand for natural products has been continuously increasing because of their significant value and new applications, mainly as pharmaceuticals. Aseptic production systems of plant secondary metabolites have improved considerably, constituting an attractive tool for increased, stable and large-scale supply of valuable molecules. Surprisingly, to date, only a few examples including taxol, shikonin, berberine and artemisinin have emerged as success cases of commercial production using this strategy. The present review focuses on the main characteristics of plant specialized metabolism and their implications for current strategies used to produce secondary compounds in axenic cultivation systems. The search for consonance between plant secondary metabolism unique features and various in vitro culture systems, including cell, tissue, organ, and engineered cultures, as well as heterologous expression in microbial platforms, is discussed. Data to date strongly suggest that attaining full potential of these biotechnology production strategies requires being able to take advantage of plant specialized metabolism singularities for improved target molecule yields and for bypassing inherent difficulties in its rational manipulation.
- MeSH
- artemisininy izolace a purifikace metabolismus MeSH
- axenická kultura MeSH
- berberin izolace a purifikace metabolismus MeSH
- biologické přípravky izolace a purifikace metabolismus MeSH
- biotechnologie metody MeSH
- buněčné kultury MeSH
- fytonutrienty biosyntéza izolace a purifikace MeSH
- metabolické inženýrství metody MeSH
- naftochinony izolace a purifikace metabolismus MeSH
- paclitaxel biosyntéza izolace a purifikace MeSH
- rostlinné buňky chemie metabolismus MeSH
- rostliny chemie genetika metabolismus MeSH
- sekundární metabolismus MeSH
- techniky tkáňových kultur MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
Microorganisms are not commonly found in the planktonic state but predominantly form dual- and multispecies biofilms in almost all natural environments. Bacteria in multispecies biofilms cooperate, compete or have neutral interactions according to the involved species. Here, the development of mono- and dual-species biofilms formed by Staphylococcus aureus and other foodborne pathogens such as Salmonella enterica subsp. enterica serovar Enteritidis, potentially pathogenic Raoultella planticola and non-pathogenic Escherichia coli over the course of 24, 48 and 72 h was studied. Biofilm formation was evaluated by the crystal violet assay (CV), enumeration of colony-forming units (CFU cm-2) and visualization using confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM). In general, Gram-negative bacterial species and S. aureus interacted in a competitive manner. The tested Gram-negative bacteria grew better in mixed dual-species biofilms than in their mono-species biofilms as determined using the CV assay, CFU ml-2enumeration, and CLSM and SEM visualization. In contrast, the growth of S. aureus biofilms was reduced when cultured in dual-species biofilms. CLSM images revealed grape-like clusters of S. aureus and monolayers of Gram-negative bacteria in both mono- and dual-species biofilms. S. aureus clusters in dual-species biofilms were significantly smaller than clusters in S. aureus mono-species biofilms.
- MeSH
- barvení a značení MeSH
- biofilmy růst a vývoj MeSH
- Enterobacteriaceae růst a vývoj fyziologie MeSH
- genciánová violeť analýza MeSH
- konfokální mikroskopie MeSH
- mikrobiální interakce * MeSH
- mikroskopie elektronová rastrovací MeSH
- počet mikrobiálních kolonií MeSH
- Staphylococcus aureus růst a vývoj fyziologie MeSH
- Publikační typ
- časopisecké články MeSH
Here, we compared the abilities of polysaccharides L900/2 and L900/3, which were previously isolated from Lactobacillus rhamnosus LOCK 0900, to modulate the immune response to bystander antigens in a mouse model of ovalbumin (OVA) sensitization. In vivo, both polysaccharides reduced the levels of OVA-specific IgE, IgE-dependent basophil degranulation and IgG2a antibodies, but had no effect on the levels of OVA-specific IgA or IgG1. Interestingly, both polysaccharides triggered recall cellular responses with distinct properties. L900/3 significantly suppressed the OVA-induced upregulations of IL-4, IL-5, IL-10 and IL-13 in re-stimulated spleen cells and mesenteric lymph nodes. Our findings support and expand on our previous in vitro studies by demonstrating that polymer L900/3 might modulate the Th1/Th2 balance and could be a promising candidate molecule for preventing allergic sensitization.
- MeSH
- alergeny imunologie MeSH
- bakteriální polysacharidy aplikace a dávkování izolace a purifikace MeSH
- bazofily imunologie MeSH
- cytokiny biosyntéza MeSH
- degranulace buněk MeSH
- imunizace * MeSH
- imunoglobulin E krev MeSH
- imunoglobulin G krev MeSH
- imunologické faktory aplikace a dávkování izolace a purifikace MeSH
- Lacticaseibacillus rhamnosus chemie MeSH
- myši MeSH
- serpiny imunologie MeSH
- zvířata MeSH
- Check Tag
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
A statistical method was developed to test for equivalence of microbial communities analysed by next-generation sequencing of amplicons. The test uses Bray-Curtis distances between the microbial community structures and is based on a two-sample jackknife procedure. This approach was applied to investigate putative effects of the antifungal biocontrol strain RU47 on fungal communities in three arable soils which were analysed by high-throughput ITS amplicon sequencing. Two contrasting workflows to produce abundance tables of operational taxonomic units from sequence data were applied. For both, the developed test indicated highly significant equivalence of the fungal communities with or without previous exposure to RU47 for all soil types, with reference to fungal community differences in conjunction with field site or cropping history. However, minor effects of RU47 on fungal communities were statistically significant using highly sensitive multivariate tests. Nearly all fungal taxa responding to RU47 increased in relative abundance indicating the absence of ecotoxicological effects. Use of the developed equivalence test is not restricted to evaluate effects on soil microbial communities by inoculants for biocontrol, bioremediation or other purposes, but could also be applied for biosafety assessment of compounds like pesticides, or genetically engineered plants.
- MeSH
- biologická kontrola škůdců metody MeSH
- biostatistika metody MeSH
- DNA fungální chemie genetika MeSH
- fylogeneze MeSH
- houby klasifikace růst a vývoj izolace a purifikace MeSH
- mezerníky ribozomální DNA chemie genetika MeSH
- očkovadla agrotechnická * MeSH
- Pseudomonas růst a vývoj MeSH
- půdní mikrobiologie * MeSH
- sekvenční analýza DNA MeSH
- shluková analýza MeSH
- společenstvo * MeSH
- Publikační typ
- časopisecké články MeSH
To find an effective drug for Zika virus, it is important to understand how numerous proteins which are critical for the virus' structure and function interact with their counterparts. One approach to inhibiting the flavivirus is to deter its ability to bind onto glycoproteins; however, the crystal structures of envelope proteins of the ever-evolving viral strains that decipher glycosidic or drug-molecular interactions are not always available. To fill this gap, we are reporting a holistic, simulation-based approach to predict compounds that will inhibit ligand binding onto a structurally unresolved protein, in this case the Zika virus envelope protein (ZVEP), by developing a three-dimensional general structure and analyzing sites at which ligands and small drug-like molecules interact. By examining how glycan molecules and small-molecule probes interact with a freshly resolved ZVEP homology model, we report the susceptibility of ZVEP to inhibition via two small molecules, ZINC33683341 and ZINC49605556-by preferentially binding onto the primary receptor responsible for the virus' virulence. Antiviral activity was confirmed when ZINC33683341 was tested in cell culture. We anticipate the results to be a starting point for drug discovery targeting Zika virus and other emerging pathogens.
- MeSH
- antivirové látky chemie farmakologie MeSH
- Cercopithecus aethiops MeSH
- knihovny malých molekul chemie farmakologie MeSH
- molekulární modely MeSH
- počítačová simulace MeSH
- polysacharidy metabolismus MeSH
- proteiny virového obalu antagonisté a inhibitory chemie MeSH
- strukturní homologie proteinů MeSH
- vazebná místa MeSH
- Vero buňky MeSH
- virová nálož účinky léků MeSH
- virus zika účinky léků metabolismus MeSH
- vztahy mezi strukturou a aktivitou MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Celiac disease (CD) is an autoimmune enteropathy initiated and sustained by the ingestion of gluten in genetically susceptible individuals. It is caused by a dysregulated immune response toward both dietary antigens, the gluten proteins of wheat, rye, and barley, and autoantigens, the enzyme tissue transglutaminase (TG2). The small intestine is the target organ. Although routine immunochemical protocols for a laboratory diagnosis of CD are available, faster, easier-to-use, and cheaper analytical devices for CD diagnosis are currently unavailable. This review focuses on biosensors, consisting of a physicochemical transducer and a bioreceptor, as promising analytical tools for diagnosis of CD and other diseases. Examples of recently developed biosensors as well as expectations for future lines of research and development in this field are presented.
- MeSH
- biosenzitivní techniky metody MeSH
- celiakie diagnóza imunologie MeSH
- elektrochemické techniky MeSH
- gliadin imunologie MeSH
- imunohistochemie MeSH
- lidé MeSH
- proteiny vázající GTP imunologie MeSH
- protilátky metabolismus MeSH
- transglutaminasy imunologie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
Magnetic particles (MPs) are currently used as a suitable alternative for peroxidase in the construction of novel biosensors, analytic and diagnostic methods. Their better chemical and thermal stabilities predestine them as appropriate pseudo-enzymatic catalysts. In this point of view, our research was focused on preparation of simply and fast method for immobilization of glucose oxidase onto surface of MPs with peroxidase-like activity. Spectrophotometric method (wavelength 450 nm) optimized for glucose determination using modified MPs has been successfully developed. Concentration curve for optimization of method was assayed, and Michaelis-Menten constant (K m) calculated, maximum reaction rate (V max), limit of detection, and correlation coefficient were determined to be 0.13 mmol/l (2.34 mg/dl), 1.79 pkat, 3.74 µmol/l (0.067 mg/dl), and 0.996, respectively. Interferences of other sugars such as sucrose, sorbitol, deoxyribose, maltose, and fructose were determined as well as effect of substances presenting in plasma (ascorbic acid, reduced glutathione, trolox, and urea). Results in comparison with positive and negative controls showed no interferences of the other sugars and no influence of plasma substances to measuring of glucose. The constructed method showed corresponding results with linear dependence and a correlation coefficient of 0.997. Possibility of repeated use of modified MPs was successfully proved.
- MeSH
- enzymy imobilizované metabolismus MeSH
- glukosaoxidasa metabolismus MeSH
- kolorimetrie metody MeSH
- krevní glukóza metabolismus MeSH
- lidé MeSH
- magnetismus * MeSH
- peroxidasy metabolismus MeSH
- spektrofotometrie MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
