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1.
Environ Microbiol ; 23(1): 484-498, 2021 01.
Artículo en Inglés | MEDLINE | ID: mdl-33258525

RESUMEN

The heterogeneous nature of lotic habitats plays an important role in the complex ecological and evolutionary processes that structure the microbial communities within them. Due to such complexity, our understanding of lotic microbial ecology still lacks conceptual frameworks for the ecological processes that shape these communities. We explored how bacterial community composition and underlying ecological assembly processes differ between lotic habitats by examining community composition and inferring community assembly processes across four major habitat types (free-living, particle-associated, biofilm on benthic stones and rocks, and sediment). This was conducted at 12 river sites from headwater streams to the main river in the River Thames, UK. Our results indicate that there are distinct differences in the bacterial communities between four major habitat types, with contrasting ecological processes shaping their community assembly processes. While the mobile free-living and particle-associated communities were consistently less diverse than the fixed sediment and biofilm communities, the latter two communities displayed higher homogeneity across the sampling sites. This indicates that the relative influence of deterministic environmental filtering is elevated in sediment and biofilm communities compared with free-living and particle-associated communities, where stochastic processes play a larger role.


Asunto(s)
Bacterias/aislamiento & purificación , Microbiota , Ríos/microbiología , Bacterias/clasificación , Bacterias/genética , Ecosistema , Filogenia , Ríos/química , Reino Unido
2.
Neurobiol Dis ; 125: 92-106, 2019 05.
Artículo en Inglés | MEDLINE | ID: mdl-30685352

RESUMEN

Intellectual disability is the most limiting hallmark of Down syndrome, for which there is no gold-standard clinical treatment yet. The endocannabinoid system is a widespread neuromodulatory system involved in multiple functions including learning and memory processes. Alterations of this system contribute to the pathogenesis of several neurological and neurodevelopmental disorders. However, the involvement of the endocannabinoid system in the pathogenesis of Down syndrome has not been explored before. We used the best-characterized preclinical model of Down syndrome, the segmentally trisomic Ts65Dn model. In male Ts65Dn mice, cannabinoid type-1 receptor (CB1R) expression was enhanced and its function increased in hippocampal excitatory terminals. Knockdown of CB1R in the hippocampus of male Ts65Dn mice restored hippocampal-dependent memory. Concomitant with this result, pharmacological inhibition of CB1R restored memory deficits, hippocampal synaptic plasticity and adult neurogenesis in the subgranular zone of the dentate gyrus. Notably, the blockade of CB1R also normalized hippocampal-dependent memory in female Ts65Dn mice. To further investigate the mechanisms involved, we used a second transgenic mouse model overexpressing a single gene candidate for Down syndrome cognitive phenotypes, the dual specificity tyrosine-phosphorylation-regulated kinase 1A (DYRK1A). CB1R pharmacological blockade similarly improved cognitive performance, synaptic plasticity and neurogenesis in transgenic male Dyrk1A mice. Our results identify CB1R as a novel druggable target potentially relevant for the improvement of cognitive deficits associated with Down syndrome.


Asunto(s)
Encéfalo/efectos de los fármacos , Antagonistas de Receptores de Cannabinoides/farmacología , Cognición/efectos de los fármacos , Síndrome de Down/metabolismo , Receptor Cannabinoide CB1/antagonistas & inhibidores , Animales , Encéfalo/metabolismo , Disfunción Cognitiva/genética , Modelos Animales de Enfermedad , Femenino , Masculino , Ratones , Ratones Transgénicos , Neurogénesis/efectos de los fármacos , Fenotipo , Piperidinas/farmacología , Pirazoles/farmacología , Receptor Cannabinoide CB1/efectos de los fármacos , Rimonabant/farmacología
3.
Mol Ecol ; 25(13): 3101-19, 2016 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-27095076

RESUMEN

Organisms continuously release DNA into their environments via shed cells, excreta, gametes and decaying material. Analysis of this 'environmental DNA' (eDNA) is revolutionizing biodiversity monitoring. eDNA outperforms many established survey methods for targeted detection of single species, but few studies have investigated how well eDNA reflects whole communities of organisms in natural environments. We investigated whether eDNA can recover accurate qualitative and quantitative information about fish communities in large lakes, by comparison to the most comprehensive long-term gill-net data set available in the UK. Seventy-eight 2L water samples were collected along depth profile transects, gill-net sites and from the shoreline in three large, deep lakes (Windermere, Bassenthwaite Lake and Derwent Water) in the English Lake District. Water samples were assayed by eDNA metabarcoding of the mitochondrial 12S and cytochrome b regions. Fourteen of the 16 species historically recorded in Windermere were detected using eDNA, compared to four species in the most recent gill-net survey, demonstrating eDNA is extremely sensitive for detecting species. A key question for biodiversity monitoring is whether eDNA can accurately estimate abundance. To test this, we used the number of sequence reads per species and the proportion of sampling sites in which a species was detected with eDNA (i.e. site occupancy) as proxies for abundance. eDNA abundance data consistently correlated with rank abundance estimates from established surveys. These results demonstrate that eDNA metabarcoding can describe fish communities in large lakes, both qualitatively and quantitatively, and has great potential as a complementary tool to established monitoring methods.


Asunto(s)
Biodiversidad , Código de Barras del ADN Taxonómico/métodos , ADN/genética , Peces/genética , Lagos , Animales , Citocromos b/genética , Monitoreo del Ambiente/métodos , Reino Unido
4.
J Clin Microbiol ; 52(8): 3011-6, 2014 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-24920767

RESUMEN

Spontaneously expectorated sputum is traditionally used as the sampling method for the investigation of lower airway infections. While guidelines exist for the handling of these samples for culture-based diagnostic microbiology, there is no comparable consensus on their handling prior to culture-independent analysis. The increasing incorporation of culture-independent approaches in diagnostic microbiology means that it is of critical importance to assess potential biases. The aim of this study was to assess the impact of delayed freezing on culture-independent microbiological analyses and to identify acceptable parameters for sample handling. Sputum samples from eight adult cystic fibrosis (CF) patients were collected and aliquoted into sterile Bijou bottles. Aliquots were stored at room temperature before being frozen at -80 °C for increasing intervals, up to a 72-h period. Samples were treated with propidium monoazide to distinguish live from dead cells prior to DNA extraction, and 16S rRNA gene pyrosequencing was used to characterize their bacterial compositions. Substantial variation was observed in samples with high-diversity bacterial communities over time, whereas little variation was observed in low-diversity communities dominated by recognized CF pathogens, regardless of time to freezing. Partitioning into common and rare species demonstrated that the rare species drove changes in similarity. The percentage abundance of anaerobes over the study significantly decreased after 12 h at room temperature (P = 0.008). Failure to stabilize samples at -80 °C within 12 h of collection results in significant changes in the detected community composition.


Asunto(s)
Bacterias/clasificación , Bacterias/aislamiento & purificación , Infecciones Bacterianas/microbiología , Fibrosis Quística/complicaciones , Infecciones del Sistema Respiratorio/microbiología , Manejo de Especímenes/métodos , Esputo/microbiología , Adulto , Bacterias/genética , Análisis por Conglomerados , ADN Ribosómico/química , ADN Ribosómico/genética , Humanos , Datos de Secuencia Molecular , Filogenia , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN , Temperatura , Factores de Tiempo
5.
Environ Microbiol ; 14(9): 2293-307, 2012 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-22591022

RESUMEN

Since industrialization global CO(2) emissions have increased, and as a consequence oceanic pH is predicted to drop by 0.3-0.4 units before the end of the century - a process coined 'ocean acidification'. Consequently, there is significant interest in how pH changes will affect the ocean's biota and integral processes. We investigated marine picoplankton (0.2-2 µm diameter) community response to predicted end of century CO(2) concentrations, via a 'high-CO(2) ' (∼ 750 ppm) large-volume (11 000 l) contained seawater mesocosm approach. We found little evidence of changes occurring in bacterial abundance or community composition due to elevated CO(2) under both phytoplankton pre-bloom/bloom and post-bloom conditions. In contrast, significant differences were observed between treatments for a number of key picoeukaryote community members. These data suggested a key outcome of ocean acidification is a more rapid exploitation of elevated CO(2) levels by photosynthetic picoeukaryotes. Thus, our study indicates the need for a more thorough understanding of picoeukaryote-mediated carbon flow within ocean acidification experiments, both in relation to picoplankton carbon sources, sinks and transfer to higher trophic levels.


Asunto(s)
Fenómenos Fisiológicos Bacterianos , Biodiversidad , Agua de Mar/química , Bacterias/clasificación , Bacterias/genética , Carbono/metabolismo , Dióxido de Carbono/química , Eucariontes/fisiología , Concentración de Iones de Hidrógeno , Océanos y Mares , Filogenia , Fitoplancton/fisiología
6.
Sci Rep ; 12(1): 14331, 2022 08 22.
Artículo en Inglés | MEDLINE | ID: mdl-35995928

RESUMEN

We use a national citizen science monitoring scheme to quantify how agricultural intensification affects honeybee diet breadth (number of plant species). To do this we used DNA metabarcoding to identify the plants present in 527 honey samples collected in 2019 across Great Britain. The species richness of forage plants was negatively correlated with arable cropping area, although this was only found early in the year when the abundance of flowering plants was more limited. Within intensively farmed areas, honeybee diets were dominated by Brassica crops (including oilseed rape). We demonstrate how the structure and complexity of honeybee foraging relationships with plants is negatively affected by the area of arable crops surrounding hives. Using information collected from the beekeepers on the incidence of an economically damaging bee disease (Deformed Wing Virus) we found that the occurrence of this disease increased where bees foraged in agricultural land where there was a high use of foliar insecticides. Understanding impacts of land use on resource availability is fundamental to assessing long-term viability of pollinator populations. These findings highlight the importance of supporting temporally timed resources as mitigation strategies to support wider pollinator population viability.


Asunto(s)
Ciencia Ciudadana , Plaguicidas , Animales , Abejas , Productos Agrícolas , Plaguicidas/toxicidad , Polinización , Virus ARN , Estaciones del Año
7.
MethodsX ; 8: 101303, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34434823

RESUMEN

Worldwide honeybees (Apis mellifera L.) are one of the most widely kept domesticated animals, supporting domestic and commercial livelihoods through the production of honey and wax, as well as in the delivery of pollination services to crops. Quantifying which plant species are foraged upon by honeybees provides insights into their nutritional status as well as patterns of landscape scale habitat utilization. Here we outline a rapid and reproducible methodology for identifying environmental DNA (eDNA) originating principally from pollen grains suspended within honey. The process is based on a DNA extraction incorporating vacuum filtration prior to universal eukaryotic internal transcribed spacer 2 region (ITS2) amplicon generation, sequencing and identification. To provide a pre-cursor to sequence phylotyping, we outline systems for error-corrected processing amplicon sequence variant abundance tables that removes chimeras. This methodology underpins the new UK National Honey Monitoring Scheme.•We compare the efficacy and speed of centrifugation and filtration systems for removing pollen from honey samples as a precursor to plant DNA barcoding.•We introduce the 'HONEYPI' informatics pipeline, an open access resource implemented in python 2.7, to ensure long-term reproducibility during the process of amplicon sequence variant classification.

8.
Microbiome ; 9(1): 19, 2021 01 22.
Artículo en Inglés | MEDLINE | ID: mdl-33482913

RESUMEN

BACKGROUND: The plant microbiome plays a vital role in determining host health and productivity. However, we lack real-world comparative understanding of the factors which shape assembly of its diverse biota, and crucially relationships between microbiota composition and plant health. Here we investigated landscape scale rhizosphere microbial assembly processes in oilseed rape (OSR), the UK's third most cultivated crop by area and the world's third largest source of vegetable oil, which suffers from yield decline associated with the frequency it is grown in rotations. By including 37 conventional farmers' fields with varying OSR rotation frequencies, we present an innovative approach to identify microbial signatures characteristic of microbiomes which are beneficial and harmful to the host. RESULTS: We show that OSR yield decline is linked to rotation frequency in real-world agricultural systems. We demonstrate fundamental differences in the environmental and agronomic drivers of protist, bacterial and fungal communities between root, rhizosphere soil and bulk soil compartments. We further discovered that the assembly of fungi, but neither bacteria nor protists, was influenced by OSR rotation frequency. However, there were individual abundant bacterial OTUs that correlated with either yield or rotation frequency. A variety of fungal and protist pathogens were detected in roots and rhizosphere soil of OSR, and several increased relative abundance in root or rhizosphere compartments as OSR rotation frequency increased. Importantly, the relative abundance of the fungal pathogen Olpidium brassicae both increased with short rotations and was significantly associated with low yield. In contrast, the root endophyte Tetracladium spp. showed the reverse associations with both rotation frequency and yield to O. brassicae, suggesting that they are signatures of a microbiome which benefits the host. We also identified a variety of novel protist and fungal clades which are highly connected within the microbiome and could play a role in determining microbiome composition. CONCLUSIONS: We show that at the landscape scale, OSR crop yield is governed by interplay between complex communities of both pathogens and beneficial biota which is modulated by rotation frequency. Our comprehensive study has identified signatures of dysbiosis within the OSR microbiome, grown in real-world agricultural systems, which could be used in strategies to promote crop yield. Video abstract.


Asunto(s)
Brassica napus/crecimiento & desarrollo , Brassica napus/microbiología , Productos Agrícolas/crecimiento & desarrollo , Productos Agrícolas/microbiología , Microbiota/genética , Aceite de Brassica napus , Microbiología del Suelo , Hongos/genética , Hongos/aislamiento & purificación , Raíces de Plantas/microbiología , Rizosfera
9.
Brain Stimul ; 13(2): 494-498, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-31919001

RESUMEN

BACKGROUND: Vagus nerve stimulation (VNS) using non-invasive approaches have attracted great attention due to their anti-epileptic, anti-depressive and pro-cognitive effects. It has been proposed that auricular transcutaneous VNS (atVNS) could benefit intellectual disability disorders, but preclinical data supporting this idea is limited. OBJECTIVE: To develop an atVNS device for mice and to test its efficacy on memory performance in naïve mice and in a mouse model for intellectual disability. METHODS: Naïve outbreed CD-1 mice and a model for fragile X syndrome, the Fmr1 knockout (Fmr1KO), were used to assess the effect of atVNS in the novel object-recognition memory performance. RESULTS: We found that atVNS significantly improves memory persistence in naïve mice. Notably, atVNS was efficacious in normalizing the object-recognition memory deficit in the Fmr1KO model. CONCLUSION: Our data show that atVNS improves memory persistence in naïve mice and in a model of intellectual disability and support further studies taking advantage of preclinical mouse models of cognitive disorders.


Asunto(s)
Discapacidad Intelectual/fisiopatología , Estimulación del Nervio Vago/métodos , Animales , Proteína de la Discapacidad Intelectual del Síndrome del Cromosoma X Frágil/genética , Discapacidad Intelectual/genética , Discapacidad Intelectual/terapia , Masculino , Ratones , Estimulación Eléctrica Transcutánea del Nervio/métodos
10.
Microbiome ; 8(1): 45, 2020 04 02.
Artículo en Inglés | MEDLINE | ID: mdl-32238195

RESUMEN

BACKGROUND: Chronic infection and concomitant airway inflammation is the leading cause of morbidity and mortality for people living with cystic fibrosis (CF). Although chronic infection in CF is undeniably polymicrobial, involving a lung microbiota, infection surveillance and control approaches remain underpinned by classical aerobic culture-based microbiology. How to use microbiomics to direct clinical management of CF airway infections remains a crucial challenge. A pivotal step towards leveraging microbiome approaches in CF clinical care is to understand the ecology of the CF lung microbiome and identify ecological patterns of CF microbiota across a wide spectrum of lung disease. Assessing sputum samples from 299 patients attending 13 CF centres in Europe and the USA, we determined whether the emerging relationship of decreasing microbiota diversity with worsening lung function could be considered a generalised pattern of CF lung microbiota and explored its potential as an informative indicator of lung disease state in CF. RESULTS: We tested and found decreasing microbiota diversity with a reduction in lung function to be a significant ecological pattern. Moreover, the loss of diversity was accompanied by an increase in microbiota dominance. Subsequently, we stratified patients into lung disease categories of increasing disease severity to further investigate relationships between microbiota characteristics and lung function, and the factors contributing to microbiota variance. Core taxa group composition became highly conserved within the severe disease category, while the rarer satellite taxa underpinned the high variability observed in the microbiota diversity. Further, the lung microbiota of individual patient were increasingly dominated by recognised CF pathogens as lung function decreased. Conversely, other bacteria, especially obligate anaerobes, increasingly dominated in those with better lung function. Ordination analyses revealed lung function and antibiotics to be main explanators of compositional variance in the microbiota and the core and satellite taxa. Biogeography was found to influence acquisition of the rarer satellite taxa. CONCLUSIONS: Our findings demonstrate that microbiota diversity and dominance, as well as the identity of the dominant bacterial species, in combination with measures of lung function, can be used as informative indicators of disease state in CF. Video Abstract.


Asunto(s)
Bacterias/clasificación , Fibrosis Quística/microbiología , Pulmón/microbiología , Pulmón/fisiopatología , Microbiota , Adulto , Antibacterianos/uso terapéutico , Bacterias/efectos de los fármacos , Fibrosis Quística/tratamiento farmacológico , Progresión de la Enfermedad , Europa (Continente) , Femenino , Humanos , Inflamación , Pulmón/efectos de los fármacos , Masculino , Pruebas de Función Respiratoria , Análisis de Secuencia de ADN , Esputo/microbiología , Estados Unidos , Adulto Joven
11.
Environ Microbiol ; 11(12): 3132-9, 2009 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-19659500

RESUMEN

Very few marine microbial communities are well characterized even with the weight of research effort presently devoted to it. Only a small proportion of this effort has been aimed at investigating temporal community structure. Here we present the first report of the application of high-throughput pyrosequencing to investigate intra-annual bacterial community structure. Microbial diversity was determined for 12 time points at the surface of the L4 sampling site in the Western English Channel. This was performed over 11 months during 2007. A total of 182 560 sequences from the V6 hyper-variable region of the small-subunit ribosomal RNA gene (16S rRNA) were obtained; there were between 11 327 and 17 339 reads per sample. Approximately 7000 genera were identified, with one in every 25 reads being attributed to a new genus; yet this level of sampling far from exhausted the total diversity present at any one time point. The total data set contained 17 673 unique sequences. Only 93 (0.5%) were found at all time points, yet these few lineages comprised 50% of the total reads sequenced. The most abundant phylum was Proteobacteria (50% of all sequenced reads), while the SAR11 clade comprised 21% of the ubiquitous reads and approximately 12% of the total sequenced reads. In contrast, 78% of all operational taxonomic units were only found at one time point and 67% were only found once, evidence of a large and transient rare assemblage. This time series shows evidence of seasonally structured community diversity. There is also evidence for seasonal succession, primarily reflecting changes among dominant taxa. These changes in structure were significantly correlated to a combination of temperature, phosphate and silicate concentrations.


Asunto(s)
Bacterias/clasificación , Biodiversidad , Monitoreo del Ambiente/métodos , Agua de Mar/microbiología , Océano Atlántico , Bacterias/genética , Filogenia , Proteobacteria/clasificación , Proteobacteria/genética , ARN Ribosómico 16S/genética , Estaciones del Año , Agua de Mar/química , Análisis de Secuencia de ADN
12.
Appl Environ Microbiol ; 75(22): 7173-81, 2009 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-19783743

RESUMEN

The bacterioneuston is the community of Bacteria present in surface microlayers, the thin surface film that forms the interface between aquatic environments and the atmosphere. In this study we compared bacterial cell abundances and bacterial community structures of the bacterioneuston and the bacterioplankton (from the subsurface water column) during a phytoplankton bloom mesocosm experiment. Bacterial cell abundance, determined by flow cytometry, followed a typical bacterioplankton response to a phytoplankton bloom, with Synechococcus and high-nucleic acid content (HNA) bacterial cell numbers initially falling, probably due to selective protist grazing. Subsequently HNA and low-nucleic acid content bacterial cells increased in abundance, but Synechococcus cells did not. There was no significant difference between bacterioneuston and bacterioplankton cell abundances during the experiment. Conversely, distinct and consistent differences between the bacterioneuston and the bacterioplankton community structures were observed. This was monitored simultaneously by Bacteria 16S rRNA gene terminal restriction fragment length polymorphism and denaturing gradient gel electrophoresis. The conserved patterns of community structure observed in all of the mesocosms indicate that the bacterioneuston is distinctive and nonrandom.


Asunto(s)
Bacterias/crecimiento & desarrollo , Biodiversidad , Agua Dulce/microbiología , Fitoplancton/crecimiento & desarrollo , Plancton/microbiología , Microbiología del Agua , Bacterias/clasificación , Bacterias/genética , Recuento de Colonia Microbiana , ADN Bacteriano/genética , Agua Dulce/química , Variación Genética , Datos de Secuencia Molecular , Océanos y Mares , Filogenia , Dinámica Poblacional , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN , Homología de Secuencia de Ácido Nucleico
13.
J Phys Chem A ; 113(6): 1040-8, 2009 Feb 12.
Artículo en Inglés | MEDLINE | ID: mdl-19146395

RESUMEN

This study explores how the electron transfer in a class of donor-bridge-acceptor (DBA) supermolecules is affected by the dynamical response of the solvent. These DBA molecules have a pendant group juxtaposed between the donor and acceptor groups (Figure 1). The pendant provides intermediate electronic coupling strengths of a few hundred wavenumbers by way of its nonbonded contacts with the donor and acceptor and it can be tuned by substituents added to the pendant. This design allows the measurement of electron transfer rates from a regime in which the mechanism is nonadiabatic to a regime in which the solvent friction modifies the rate substantially. The rate constants and mechanistic parameters are compared with the expectations of models for solvent dynamical effects on the reaction rate.

14.
Nat Commun ; 9(1): 3033, 2018 08 02.
Artículo en Inglés | MEDLINE | ID: mdl-30072764

RESUMEN

Soil microbial communities play a crucial role in ecosystem functioning, but it is unknown how co-occurrence networks within these communities respond to disturbances such as climate extremes. This represents an important knowledge gap because changes in microbial networks could have implications for their functioning and vulnerability to future disturbances. Here, we show in grassland mesocosms that drought promotes destabilising properties in soil bacterial, but not fungal, co-occurrence networks, and that changes in bacterial communities link more strongly to soil functioning during recovery than do changes in fungal communities. Moreover, we reveal that drought has a prolonged effect on bacterial communities and their co-occurrence networks via changes in vegetation composition and resultant reductions in soil moisture. Our results provide new insight in the mechanisms through which drought alters soil microbial communities with potential long-term consequences, including future plant community composition and the ability of aboveground and belowground communities to withstand future disturbances.


Asunto(s)
Bacterias/metabolismo , Sequías , Hongos/metabolismo , Microbiología del Suelo , Biomasa , Ecosistema , Modelos Biológicos , Plantas/microbiología , Suelo
15.
Ecol Evol ; 7(3): 855-862, 2017 02.
Artículo en Inglés | MEDLINE | ID: mdl-28168022

RESUMEN

Climate change can influence soil microorganisms directly by altering their growth and activity but also indirectly via effects on the vegetation, which modifies the availability of resources. Direct impacts of climate change on soil microorganisms can occur rapidly, whereas indirect effects mediated by shifts in plant community composition are not immediately apparent and likely to increase over time. We used molecular fingerprinting of bacterial and fungal communities in the soil to investigate the effects of 17 years of temperature and rainfall manipulations in a species-rich grassland near Buxton, UK. We compared shifts in microbial community structure to changes in plant species composition and key plant traits across 78 microsites within plots subjected to winter heating, rainfall supplementation, or summer drought. We observed marked shifts in soil fungal and bacterial community structure in response to chronic summer drought. Importantly, although dominant microbial taxa were largely unaffected by drought, there were substantial changes in the abundances of subordinate fungal and bacterial taxa. In contrast to short-term studies that report high resistance of soil fungi to drought, we observed substantial losses of fungal taxa in the summer drought treatments. There was moderate concordance between soil microbial communities and plant species composition within microsites. Vector fitting of community-weighted mean plant traits to ordinations of soil bacterial and fungal communities showed that shifts in soil microbial community structure were related to plant traits representing the quality of resources available to soil microorganisms: the construction cost of leaf material, foliar carbon-to-nitrogen ratios, and leaf dry matter content. Thus, our study provides evidence that climate change could affect soil microbial communities indirectly via changes in plant inputs and highlights the importance of considering long-term climate change effects, especially in nutrient-poor systems with slow-growing vegetation.

16.
ISME J ; 11(3): 663-675, 2017 03.
Artículo en Inglés | MEDLINE | ID: mdl-27983724

RESUMEN

Infection by gastrointestinal helminths of humans, livestock and wild animals is common, but the impact of such endoparasites on wild hosts and their gut microbiota represents an important overlooked component of population dynamics. Wild host gut microbiota and endoparasites occupy the same physical niche spaces with both affecting host nutrition and health. However, associations between the two are poorly understood. Here we used the commonly parasitized European shag (Phalacrocorax aristotelis) as a model wild host. Forty live adults from the same colony were sampled. Endoscopy was employed to quantify helminth infection in situ. Microbiota from the significantly distinct proventriculus (site of infection), cloacal and faecal gastrointestinal tract microbiomes were characterised using 16S rRNA gene-targeted high-throughput sequencing. We found increasingly strong associations between helminth infection and microbiota composition progressing away from the site of infection, observing a pronounced dysbiosis in microbiota when samples were partitioned into high- and low-burden groups. We posit this dysbiosis is predominately explained by helminths inducing an anti-inflammatory environment in the proventriculus, diverting host immune responses away from themselves. This study, within live wild animals, provides a vital foundation to better understand the mechanisms that underpin the three-way relationship between helminths, microbiota and hosts.


Asunto(s)
Infecciones por Ascaridida/veterinaria , Ascaridoidea/clasificación , Ascaridoidea/aislamiento & purificación , Enfermedades de las Aves/parasitología , Aves , Tracto Gastrointestinal/parasitología , Animales , Infecciones por Ascaridida/parasitología , Ascaridoidea/genética , Aves/clasificación , Femenino , Masculino
17.
Front Microbiol ; 7: 1247, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27555839

RESUMEN

Despite several lines of observational evidence, there is a lack of consensus on whether higher fungal:bacterial (F:B) ratios directly cause higher soil carbon (C) storage. We employed RNA sequencing, protein profiling and isotope tracer techniques to evaluate whether differing F:B ratios are associated with differences in C storage. A mesocosm (13)C labeled foliar litter decomposition experiment was performed in two soils that were similar in their physico-chemical properties but differed in microbial community structure, specifically their F:B ratio (determined by PLFA analyses, RNA sequencing and protein profiling; all three corroborating each other). Following litter addition, we observed a consistent increase in abundance of fungal phyla; and greater increases in the fungal dominated soil; implicating the role of fungi in litter decomposition. Litter derived (13)C in respired CO2 was consistently lower, and residual (13)C in bulk SOM was higher in high F:B soil demonstrating greater C storage potential in the F:B dominated soil. We conclude that in this soil system, the increased abundance of fungi in both soils and the altered C cycling patterns in the F:B dominated soils highlight the significant role of fungi in litter decomposition and indicate that F:B ratios are linked to higher C storage potential.

18.
ISME J ; 10(5): 1081-91, 2016 May.
Artículo en Inglés | MEDLINE | ID: mdl-26555248

RESUMEN

Pulmonary symptoms in cystic fibrosis (CF) begin in early life with chronic lung infections and concomitant airway inflammation leading to progressive loss of lung function. Gradual pulmonary function decline is interspersed with periods of acute worsening of respiratory symptoms known as CF pulmonary exacerbations (CFPEs). Cumulatively, CFPEs are associated with more rapid disease progression. In this study multiple sputum samples were collected from adult CF patients over the course of CFPEs to better understand how changes in microbiota are associated with CFPE onset and management. Data were divided into five clinical periods: pre-CFPE baseline, CFPE, antibiotic treatment, recovery, and post-CFPE baseline. Samples were treated with propidium monoazide prior to DNA extraction, to remove the impact of bacterial cell death artefacts following antibiotic treatment, and then characterised by 16S rRNA gene-targeted high-throughput sequencing. Partitioning CF microbiota into core and rare groups revealed compositional resistance to CFPE and resilience to antibiotics interventions. Mixed effects modelling of core microbiota members revealed no significant negative impact on the relative abundance of Pseudomonas aeruginosa across the exacerbation cycle. Our findings have implications for current CFPE management strategies, supporting reassessment of existing antimicrobial treatment regimens, as antimicrobial resistance by pathogens and other members of the microbiota may be significant contributing factors.


Asunto(s)
Fibrosis Quística/microbiología , Fibrosis Quística/fisiopatología , Microbiota , Infecciones del Sistema Respiratorio/microbiología , Esputo/microbiología , Adolescente , Adulto , Antibacterianos/uso terapéutico , Enfermedad Crónica , Fibrosis Quística/complicaciones , Fibrosis Quística/tratamiento farmacológico , ADN Bacteriano/genética , Femenino , Humanos , Pulmón/microbiología , Pulmón/fisiopatología , Masculino , Persona de Mediana Edad , Pseudomonas aeruginosa/genética , Pseudomonas aeruginosa/aislamiento & purificación , ARN Ribosómico 16S/genética , Infecciones del Sistema Respiratorio/complicaciones , Adulto Joven
19.
FEMS Microbiol Ecol ; 91(3)2015 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-25764559

RESUMEN

Microbial biofilms are common on lithic surfaces, including stone buildings. However, the ecology of these communities is poorly understood. Few studies have focused on the spatial characteristics of lithobiontic biofilms, despite the fact that spatial structure has been demonstrated to influence ecosystem function (and hence biodegradation) and community diversity. Furthermore, relatively few studies have utilized molecular techniques to characterize these communities, even though molecular methods have revealed unexpected microbial diversity in other habitats. This study investigated (1) the spatial structure and (2) the taxonomic composition of an epilithic biofilm using molecular techniques, namely amplicon pyrosequencing and terminal restriction fragment length polymorphism. Dispersion indices and Mantel correlograms were used to test for the presence of spatial structure in the biofilm. Diversity metrics and rank-abundance distributions (RADs) were also generated. The study revealed spatial structure on a centimetre scale in eukaryotic microbes (fungi and algae), but not the bacteria. Fungal and bacterial communities were highly diverse; algal communities much less so. The RADs were characterized by a distinctive 'hollow' (concave up) profile and long tails of rare taxa. These findings have implications for understanding the ecology of epilithic biofilms and the spatial heterogeneity of stone biodeterioration.


Asunto(s)
Bacterias/clasificación , Biopelículas/clasificación , Hongos/fisiología , Microbiota/genética , Bacterias/genética , Fenómenos Fisiológicos Bacterianos , Secuencia de Bases , Biodegradación Ambiental , Chlorophyta/microbiología , Ecosistema , Hongos/clasificación , Hongos/genética , Polimorfismo de Longitud del Fragmento de Restricción , Análisis de Secuencia de ADN
20.
Methods Ecol Evol ; 6(8): 973-980, 2015 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-27570615

RESUMEN

Studying fungal biodiversity using data generated from Illumina MiSeq sequencing platforms poses a number of bioinformatic challenges with the analysis typically involving a large number of tools for each analytical step from quality filtering to generating identified operational taxonomic unit (OTU) abundance tables.Here, we introduce PIPITS, an open-source stand-alone suite of software for automated processing of Illumina MiSeq sequences for fungal community analysis. PIPITS exploits a number of state of the art applications to process paired-end reads from quality filtering to producing OTU abundance tables.We provide detailed descriptions of the pipeline and show its utility in the analysis of 9 396 092 sequences generated on the MiSeq platform from Illumina MiSeq. PIPITS is the first automated bioinformatics pipeline dedicated for fungal ITS sequences which incorporates ITSx to extract subregions of ITS and exploits the latest RDP Classifier to classify sequences against the curated UNITE fungal data set.

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