Genotyping and antibiotic resistance of thermophilic Campylobacter isolated from chicken and pig meat in Vietnam

Background Campylobacter species are recognized as the most common cause of foodborne bacterial gastroenteritis in humans. In this study nine Campylobacter strains isolated from chicken meat and pork in Hanoi, Vietnam, were characterized using molecular methods and tested for antibiotic resistance. Results The nine isolates (eight C. jejuni and one C. coli) were identified by multiplex PCR, and tested for the presence or absence of 29 gene loci associated with virulence, lipooligosaccharide (LOS) biosynthesis and further functions. flaA typing, multilocus sequence typing and microarray assay investigation showed a high degree of genetic diversity among these isolates. In all isolates motility genes (flaA, flaB, flhA, fliM), colonization associated genes (cadF, docB), toxin production genes (cdtA, cdtB, secD, secF), and the LOS biosynthesis gene pglB were detected. Eight gene loci (fliY, virB11, Cje1278, Cj1434c, Cj1138, Cj1438c, Cj1440c, Cj1136) could not be detected by PCR. A differing presence of the gene loci ciaB (22.2 %), Cje1280 (77.8 %), docC (66.7 %), and cgtB (55.6 %) was found. iamA, cdtC, and the type 6 secretion system were present in all C. jejuni isolates but not in C. coli. flaA typing resulted in five different genotypes within C. jejuni, MLST classified the isolates into seven sequence types (ST-5155, ST-6736, ST-2837, ST-4395, ST-5799, ST-4099 and ST-860). The microarray assay analysis showed a high genetic diversity within Vietnamese Campylobacter isolates which resulted in eight different types for C. jejuni. Antibiotic susceptibility profiles showed that all isolates were sensitive to gentamicin and most isolates (88.8 %) were sensitive to chloramphenicol, erythromycin and streptomycin. Resistance rates to nalidixic acid, tetracycline and ciprofloxacin were 88.9, 77.8 and 66.7 %, respectively. Conclusions To the best of our knowledge, this study is the first report that shows high genetic diversity and remarkable antibiotic resistance of Campylobacter strains isolated from meat in Vietnam which can be considered of high public health significance. These preliminary data show that large scale screenings are justified to assess the relevance of Campylobacter infections on human health in Vietnam

Genetics of Dispersal

Dispersal is a process of central importance for the ecological and evolutionary dynamics of populations and communities, because of its diverse consequences for gene flow and demography. It is subject to evolutionary change, which begs the question, what is the genetic basis of this potentially complex trait? To address this question, we (i) review the empirical literature on the genetic basis of dispersal, (ii) explore how theoretical investigations of the evolution of dispersal have represented the genetics of dispersal, and (iii) discuss how the genetic basis of dispersal influences theoretical predictions of the evolution of dispersal and potential consequences. Dispersal has a detectable genetic basis in many organisms, from bacteria to plants and animals. Generally, there is evidence for significant genetic variation for dispersal or dispersal-related phenotypes or evidence for the micro-evolution of dispersal in natural populations. Dispersal is typically the outcome of several interacting traits, and this complexity is reflected in its genetic architecture: while some genes of moderate to large effect can influence certain aspects of dispersal, dispersal traits are typically polygenic. Correlations among dispersal traits as well as between dispersal traits and other traits under selection are common, and the genetic basis of dispersal can be highly environment-dependent. By contrast, models have historically considered a highly simplified genetic architecture of dispersal. It is only recently that models have started to consider multiple loci influencing dispersal, as well as non-additive effects such as dominance and epistasis, showing that the genetic basis of dispersal can influence evolutionary rates and outcomes, especially under non-equilibrium conditions. For example, the number of loci controlling dispersal can influence projected rates of dispersal evolution during range shifts and corresponding demographic impacts. Incorporating more realism in the genetic architecture of dispersal is thus necessary to enable models to move beyond the purely theoretical towards making more useful predictions of evolutionary and ecological dynamics under current and future environmental conditions. To inform these advances, empirical studies need to answer outstanding questions concerning whether specific genes underlie dispersal variation, the genetic architecture of context-dependent dispersal phenotypes and behaviours, and correlations among dispersal and other traits.Peer reviewe

Major Structural Differences and Novel Potential Virulence Mechanisms from the Genomes of Multiple Campylobacter Species

Sequencing and comparative genome analysis of four strains of Campylobacter including C. lari RM2100, C. upsaliensis RM3195, and C. coli RM2228 has revealed major structural differences that are associated with the insertion of phage- and plasmid-like genomic islands, as well as major variations in the lipooligosaccharide complex. Poly G tracts are longer, are greater in number, and show greater variability in C. upsaliensis than in the other species. Many genes involved in host colonization, including racR/S, cadF, cdt, ciaB, and flagellin genes, are conserved across the species, but variations that appear to be species specific are evident for a lipooligosaccharide locus, a capsular (extracellular) polysaccharide locus, and a novel Campylobacter putative licABCD virulence locus. The strains also vary in their metabolic profiles, as well as their resistance profiles to a range of antibiotics. It is evident that the newly identified hypothetical and conserved hypothetical proteins, as well as uncharacterized two-component regulatory systems and membrane proteins, may hold additional significant information on the major differences in virulence among the species, as well as the specificity of the strains for particular hosts

Comments on paper by M. Arai "Aptian/Albian (Early Cretaceous) paleogeography of the South Atlantic: a paleontological perspective"

Institute of Geosciences and Exact Sciences Universidade Estadual Paulista-UnespInstitute of Biosciences Department of Zoology Universidade Estadual Paulista-UnespInstitute of Geosciences and Exact Sciences Universidade Estadual Paulista-UnespInstitute of Biosciences Department of Zoology Universidade Estadual Paulista-Unes

The JECAM SAR Inter-Comparison Experiment: Comparing agriculture classification results utilizing a well-established operational decision tree methodology incorporating a variety of C-band SAR and optical imagery applied to 13 worldwide, diverse agriculture systems

Synthetic Aperture Radar (SAR) data have been incorporated in operational crop inventories with many advantages, particularly the availability of data under cloudy conditions and the structural information that is gained for agricultural vegetation. The Joint Experiment for Crop Assessment and Monitoring (JECAM) is the research and development branch of GEOGLAM (Group on Earth Observations Global Agricultural Monitoring), a G20 initiative to improve the global monitoring of agriculture through the use of Earth Observation (EO) data and remote sensing. The JECAM SAR Inter-Comparison Experiment, led by Agriculture and Agri-Food Canada (AAFC), is a multi-year, multi-partner project that aims to compare global methods for SAR crop monitoring and inventory. AAFC's operational SAR/optical crop inventory decision tree-based methodology has been successfully used to classify the agriculture extent of Canada since 2011. Data sets of RADARSAT-2 and Sentinel-1 SAR imagery, and optical imagery including Landsat8 and Sentinel-2 were prepared for this experiment using a suite of best practices to ensure consistency across 13 participating sites. The results from applying AAFC's operational crop inventory methodology to the other JECAM partners' sites will be discussed for optimized data sets of: one SAR and one optical image per month of the growing season; a SAR only data set utilizing all available C-band data for a growing season; and for a “kitchen sink” data set where all available SAR and optical data for a growing season were included in the classifier. Preliminary results from other JECAM Partners' crop classification methodologies will be discussed. Finally, there will be a brief discussion on the next two components of the JECAM SAR Inter-Comparison Experiment, including the use of compact polarimetry parameters for crop identification and monitoring, and the use of multi-frequency SAR for crop classification

Accommodating Dynamic Oceanographic Processes and Pelagic Biodiversity in Marine Conservation Planning

Pelagic ecosystems support a significant and vital component of the ocean's productivity and biodiversity. They are also heavily exploited and, as a result, are the focus of numerous spatial planning initiatives. Over the past decade, there has been increasing enthusiasm for protected areas as a tool for pelagic conservation, however, few have been implemented. Here we demonstrate an approach to plan protected areas that address the physical and biological dynamics typical of the pelagic realm. Specifically, we provide an example of an approach to planning protected areas that integrates pelagic and benthic conservation in the southern Benguela and Agulhas Bank ecosystems off South Africa. Our aim was to represent species of importance to fisheries and species of conservation concern within protected areas. In addition to representation, we ensured that protected areas were designed to consider pelagic dynamics, characterized from time-series data on key oceanographic processes, together with data on the abundance of small pelagic fishes. We found that, to have the highest likelihood of reaching conservation targets, protected area selection should be based on time-specific data rather than data averaged across time. More generally, we argue that innovative methods are needed to conserve ephemeral and dynamic pelagic biodiversity

Does pebble abrasion influence detrital age population statistics? A numerical investigation of natural datasets

Pebble abrasion is a key factor controlling the release of minerals into sand, but few attempts have been made to model how it could influence the liberation of minerals into the size fraction used in detrital geochronology. We perform a series of experiments with an abrasion model to test this influence using natural and synthetic data sets. Our results demonstrate that pebble abrasion can change the zircon mixing proportions of upstream source units as well as the age distribution of mixed fluvial sands. This change is particularly significant when there is strong contrast in rock resistance within the watershed. Pebble abrasion is one of many factors that can change the mixing proportion of sands, including hillslope gravel supply, erosion rates, and mineral fertility. In our study case (Marsyandi watershed, Himalaya), the abrasion model predicts age distributions that are statistically indistinguishable from those predicted by a no‐abrasion model. However, the relative erosion rates estimated by our model largely differ from the results of a no‐abrasion model and are closer to those from other studies that suggest a strong correlation between modern erosion rates, tectonics, and precipitation intensity in the Marsyandi watershed. These findings highlight that, even in cases where there is no statistical evidence of change between the modeled age distributions, abrasion can affect the erosion rates estimated from them. Therefore, quantifying the influence of abrasion on sand production is an essential step not only to predict mixing proportions but also to accurately retrieve erosion rates from the measured grain age distributions

Comparing Notes: Recording and Criticism

This chapter charts the ways in which recording has changed the nature of music criticism. It both provides an overview of the history of recording and music criticism, from the advent of Edison’s Phonograph to the present day, and examines the issues arising from this new technology and the consequent transformation of critical thought and practice