Longitudinal survey of total airborne bacterial and archaeal concentrations and bacterial diversity in enriched colony housing and aviaries for laying hens.

Conventional cages for laying hens will be banned in Canada as of 2036, and the egg industry is transitioning toward enriched colony housing and aviaries. While higher concentrations of particulate matter have been previously reported in aviaries and other cage-free housing systems, concentrations of total bacteria and archaea suspended in the air are still uncharacterized in Canadian enriched colonies and aviaries. The aim of the present study was to conduct a longitudinal survey of airborne total bacteria and of airborne total archaea in twelve enriched colonies and twelve aviaries in Eastern Canada during a whole laying period.

Genomic insights into cryptic cycles of microbial hydrocarbon production and degradation in contiguous freshwater and marine microbiomes.

Background: Cyanobacteria and eukaryotic phytoplankton produce long-chain alkanes and generate around 100 times greater quantities of hydrocarbons in the ocean compared to natural seeps and anthropogenic sources. Yet, these compounds do not accumulate in the water column, suggesting rapid biodegradation by co-localized microbial populations. Despite their ecological importance, the identities of microbes involved in this cryptic hydrocarbon cycle are mostly unknown.

Into the darkness of the microbial dark matter activities through expression profiles of populations.

form a highly diverse and widespread superphylum of uncultured microorganisms representing a third of the global microbial diversity. Most of our knowledge on putative physiology relies on metagenomic mining and metagenome-assembled genomes, but the activities and the ecophysiology of these microorganisms have been rarely explored, leaving the role of in ecosystems elusive. Using a genome-centric metatranscriptomic approach, we analyzed the diel and seasonal gene transcription profiles of 18 populations in brackish microbial mats to test whether our understanding of metabolism allows the extrapolation of their activities.

Genomic evidence of functional diversity in DPANN archaea, from oxic species to anoxic vampiristic consortia.

DPANN archaea account for half of the archaeal diversity of the biosphere, but with few cultivated representatives, their metabolic potential and environmental functions are poorly understood. The extreme geochemical and environmental conditions in meromictic ice-capped Lake A, in the Canadian High Arctic, provided an isolated, stratified model ecosystem to resolve the distribution and metabolism of uncultured aquatic DPANN archaea living across extreme redox and salinity gradients, from freshwater oxygenated conditions, to saline, anoxic, sulfidic waters. We recovered 28 metagenome-assembled genomes (MAGs) of DPANN archaea that provided genetic insights into their ecological function.

Transcriptomic evidence for versatile metabolic activities of mercury cycling microorganisms in brackish microbial mats.

Methylmercury, biomagnifying through food chains, is highly toxic for aquatic life. Its production and degradation are largely driven by microbial transformations; however, diversity and metabolic activity of mercury transformers, resulting in methylmercury concentrations in environments, remain poorly understood. Microbial mats are thick biofilms where oxic and anoxic metabolisms cooccur, providing opportunities to investigate the complexity of the microbial mercury transformations over contrasted redox conditions.

Syntrophic Hydrocarbon Degradation in a Decommissioned Off-Shore Subsea Oil Storage Structure.

Over the last decade, metagenomic studies have revealed the impact of oil production on the microbial ecology of petroleum reservoirs. However, despite their fundamental roles in bioremediation of hydrocarbons, biocorrosion, biofouling and hydrogen sulfide production, oil field and oil production infrastructure microbiomes are poorly explored. Understanding of microbial activities within oil production facilities is therefore crucial for environmental risk mitigation, most notably during decommissioning.

Genomic evidence for sulfur intermediates as new biogeochemical hubs in a model aquatic microbial ecosystem.

Background: The sulfur cycle encompasses a series of complex aerobic and anaerobic transformations of S-containing molecules and plays a fundamental role in cellular and ecosystem-level processes, influencing biological carbon transfers and other biogeochemical cycles. Despite their importance, the microbial communities and metabolic pathways involved in these transformations remain poorly understood, especially for inorganic sulfur compounds of intermediate oxidation states (thiosulfate, tetrathionate, sulfite, polysulfides). Isolated and highly stratified, the extreme geochemical and environmental features of meromictic ice-capped Lake A, in the Canadian High Arctic, provided an ideal model ecosystem to resolve the distribution and metabolism of aquatic sulfur cycling microorganisms along redox and salinity gradients.

Rapid Changes in Microbial Community Structures along a Meandering River.

Streams and rivers convey freshwater from lands to the oceans, transporting various organic particles, minerals, and living organisms. Microbial communities are key components of freshwater food webs and take up, utilize, and transform this material. However, there are still important gaps in our understanding of the dynamic of these organisms along the river channels.

Pulmonary tuberculosis: Evaluation of current diagnostic strategy.

Objective: To identify tools that will result in faster diagnosis, making the current pulmonary tuberculosis strategy more efficient.

Patients And Methods: A 4-year (2015-2018) retrospective study. The gold standard for diagnosis was a positive culture from a respiratory specimen.

Annual Protist Community Dynamics in a Freshwater Ecosystem Undergoing Contrasted Climatic Conditions: The Saint-Charles River (Canada).

Protists are key stone components of aquatic ecosystems, sustaining primary productivity and aquatic food webs. However, their diversity, ecology and structuring factors shaping their temporal distribution remain strongly misunderstood in freshwaters. Using high-throughput sequencing on water samples collected over 16 different months (including two summer and two winter periods), combined with geochemical measurements and climate monitoring, we comprehensively determined the pico- and nanoeukaryotic community composition and dynamics in a Canadian river undergoing prolonged ice-cover winters.

Microbial Community Structure and Methane Cycling Potential along a Thermokarst Pond-Peatland Continuum.

The thawing of ice-rich permafrost soils in northern peatlands leads to the formation of thermokarst ponds, surrounded by organic-rich soils. These aquatic ecosystems are sites of intense microbial activity, and CO and CH emissions. Many of the pond systems in northern landscapes and their surrounding peatlands are hydrologically contiguous, but little is known about the microbial connectivity of concentric habitats around the thermokarst ponds, or the effects of peat accumulation and infilling on the microbial communities.

Contrasting Winter Versus Summer Microbial Communities and Metabolic Functions in a Permafrost Thaw Lake.

Permafrost thawing results in the formation of thermokarst lakes, which are biogeochemical hotspots in northern landscapes and strong emitters of greenhouse gasses to the atmosphere. Most studies of thermokarst lakes have been in summer, despite the predominance of winter and ice-cover over much of the year, and the microbial ecology of these waters under ice remains poorly understood. Here we first compared the summer versus winter microbiomes of a subarctic thermokarst lake using DNA- and RNA-based 16S rRNA amplicon sequencing and qPCR.

Proposition of a safe Mycobacterium tuberculosis complex denaturation method that does not compromise the integrity of DNA for whole-genome sequencing.

Whole-genome sequencing plays now a leading role in epidemiologic studies of tuberculosis. DNA extraction of Mycobacterium tuberculosis complex (MTBC) requires complete inactivation of the strains, to be handled for further molecular procedures. In this study we compared two chloroform-based denaturation methods (one with a step of heat killing, one without) to a traditional heat inactivation method.

Contrasting Pathways for Anaerobic Methane Oxidation in Gulf of Mexico Cold Seep Sediments.

Gulf of Mexico sediments harbor numerous hydrocarbon seeps associated with high sedimentation rates and thermal maturation of organic matter. These ecosystems host abundant and diverse microbial communities that directly or indirectly metabolize components of the emitted fluid. To investigate microbial function and activities in these ecosystems, metabolic potential (metagenomic) and gene expression (metatranscriptomic) analyses of two cold seep areas of the Gulf of Mexico were carried out.

Multiple Strategies for Light-Harvesting, Photoprotection, and Carbon Flow in High Latitude Microbial Mats.

Microbial mats are ubiquitous in polar freshwater ecosystems and sustain high concentrations of biomass despite the extreme seasonal variations in light and temperature. Here we aimed to resolve genomic adaptations for light-harvesting, bright-light protection, and carbon flow in mats that undergo seasonal freeze-up. To bracket a range of communities in shallow water habitats, we sampled cyanobacterial mats in the thawed littoral zone of two lakes situated at the northern and southern limits of the Canadian Arctic permafrost zone.

Beyond the tip of the iceberg; a new view of the diversity of sulfite- and sulfate-reducing microorganisms.

Sulfite-reducing and sulfate-reducing microorganisms (SRM) play important roles in anoxic environments, linking the sulfur and carbon cycles. With climate warming, the distribution of anoxic habitats conductive to dissimilatory SRM is expanding. Consequently, we hypothesize that novel SRM are likely to emerge from the rare biosphere triggered by environmental changes.

Comparative metagenomics of hydrocarbon and methane seeps of the Gulf of Mexico.

Oil and gas percolate profusely through the sediments of the Gulf of Mexico, leading to numerous seeps at the seafloor, where complex microbial, and sometimes animal communities flourish. Sediments from three areas (two cold seeps with contrasting hydrocarbon composition and a site outside any area of active seepage) of the Gulf of Mexico were investigated and compared. Consistent with the existence of a seep microbiome, a distinct microbial community was observed in seep areas compared to sediment from outside areas of active seepage.

High-throughput sequencing of multiple amplicons for barcoding and integrative taxonomy.

Until now, the potential of NGS for the construction of barcode libraries or integrative taxonomy has been seldom realised. Here, we amplified (two-step PCR) and simultaneously sequenced (MiSeq) multiple markers from hundreds of fig wasp specimens. We also developed a workflow for quality control of the data.

Phylogenetic and functional diversity of microbial communities associated with subsurface sediments of the Sonora Margin, Guaymas Basin.

Subsurface sediments of the Sonora Margin (Guaymas Basin), located in proximity of active cold seep sites were explored. The taxonomic and functional diversity of bacterial and archaeal communities were investigated from 1 to 10 meters below the seafloor. Microbial community structure and abundance and distribution of dominant populations were assessed using complementary molecular approaches (Ribosomal Intergenic Spacer Analysis, 16S rRNA libraries and quantitative PCR with an extensive primers set) and correlated to comprehensive geochemical data.

Influence of DNA extraction method, 16S rRNA targeted hypervariable regions, and sample origin on microbial diversity detected by 454 pyrosequencing in marine chemosynthetic ecosystems.

Next-generation sequencing (NGS) opens up exciting possibilities for improving our knowledge of environmental microbial diversity, allowing rapid and cost-effective identification of both cultivated and uncultivated microorganisms. However, library preparation, sequencing, and analysis of the results can provide inaccurate representations of the studied community compositions. Therefore, all these steps need to be taken into account carefully.

Bacterial communities and syntrophic associations involved in anaerobic oxidation of methane process of the Sonora Margin cold seeps, Guaymas Basin.

The Sonora Margin cold seeps present on the seafloor a patchiness pattern of white microbial mats surrounded by polychaete and gastropod beds. These surface assemblages are fuelled by abundant organic inputs sedimenting from the water column and upward-flowing seep fluids. Elevated microbial density was observed in the underlying sediments.

Archaeal and anaerobic methane oxidizer communities in the Sonora Margin cold seeps, Guaymas Basin (Gulf of California).

Cold seeps, located along the Sonora Margin transform fault in the Guaymas Basin, were extensively explored during the 'BIG' cruise in June 2010. They present a seafloor mosaic pattern consisting of different faunal assemblages and microbial mats. To investigate this mostly unknown cold and hydrocarbon-rich environment, geochemical and microbiological surveys of the sediments underlying two microbial mats and a surrounding macrofaunal habitat were analyzed in detail.

Limited value of angiogenic factors in obese women.

We performed a case-control study assessing the predictive value of sVEGFR and PlGF for preeclampsia in a population with high obesity prevalence. Body mass index and circulating mean concentrations of sVEGFR and PlGF were significantly higher in preeclamptic women. However, a two variable model associating sVEGFR and PlGF dosages was not better than the model including only age and BMI.

[Treatment duration of extra-pulmonary tuberculosis: 6 months or more? TB-INFO database analysis].

Purpose: The recommended duration of pulmonary tuberculosis therapy is 6 months. For extrapulmonary tuberculosis, treatment duration depends on tuberculosis involvement and HIV status. The objective of this study was to describe the main characteristics of a cohort of extrapulmonary tuberculosis patients, to compare patients with a 6-month treatment to those with more than a 6-month treatment, and to analyze the compliance of medical centres with recommended duration of treatment.