Publications by authors named "Ken Dewar"

Article Synopsis
  • Thermophily is a special trait found in some fungi, mostly in three families and a few others, making them able to live in hot environments.
  • Scientists studied many types of fungi and discovered that being able to thrive in heat is a common feature among certain groups of these fungi, but they have fewer genes for things like defense compared to those that live in normal temperatures.
  • The study also found that certain proteins in these fungi are designed to work well at high temperatures, which can be helpful for industries that need special enzymes for their processes.
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  • The study investigates the factors affecting the expansion of tandem repeats, focusing on the FGF14 (GAA)·(TTC) repeat locus in a large sample of 2,530 individuals through advanced sequencing techniques.
  • Researchers discovered a prevalent 5'-flanking variant present in over 70% of alleles, which is linked to nonpathogenic alleles and the ancestral lineage of this genetic marker.
  • This common variant is associated with greater stability of the tandem repeat during inheritance and improved accessibility of chromatin, suggesting a role in preventing pathological expansion.
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The structural arrangements of bacterial chromosomes vary widely between closely related species and can result in significant phenotypic outcomes. The appearance of large-scale chromosomal inversions that are symmetric relative to markers for the origin of replication () has been previously observed; however, the overall prevalence of replication-associated structural rearrangements (RASRs) in bacteria and their causal mechanisms are currently unknown. Here, we systematically identify the locations of RASRs in species with multiple complete-sequenced genomes and investigate potential mediating biological mechanisms.

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Insects have developed various adaptations to survive harsh winter conditions. Among freeze-intolerant species, some produce "antifreeze proteins" (AFPs) that bind to nascent ice crystals and inhibit further ice growth. Such is the case of the spruce budworm, Choristoneura fumiferana (Lepidoptera: Tortricidae), a destructive North American conifer pest that can withstand temperatures below -30°C.

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Carbapenemase-producing including KPC-2 producers, have become a major clinical problem. During an outbreak in Quebec City, Canada, KPC-2-producing and were isolated from a patient six weeks apart. We determined their complete genome sequences.

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Here, we report the complete-genome assemblies of biofilm isolates 201A and 204H. They possess six and seven plasmids, respectively, with a size ranging from 44 kb to 159 kb. Genomic comparisons place the two strains into one new species belonging to the genus as novel representatives of the group.

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Background: The olive fruit fly, Bactrocera oleae, is the most important pest in the olive fruit agribusiness industry. This is because female flies lay their eggs in the unripe fruits and upon hatching the larvae feed on the fruits thus destroying them. The lack of a high-quality genome and other genomic and transcriptomic data has hindered progress in understanding the fly's biology and proposing alternative control methods to pesticide use.

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Aims/hypothesis: Drug and surgical-based therapies in type 2 diabetes are associated with altered gut microbiota architecture. Here we investigated the role of the gut microbiome in improved glucose homeostasis following bariatric surgery.

Methods: We carried out gut microbiome analyses in gastrectomised (by vertical sleeve gastrectomy [VSG]) rats of the Goto-Kakizaki (GK) non-obese model of spontaneously occurring type 2 diabetes, followed by physiological studies in the GK rat.

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Two subspecies of Asian gypsy moth (AGM), Lymantria dispar asiatica and L. dispar japonica, pose a serious alien invasive threat to North American forests. Despite decades of research on the ecology and biology of this pest, limited AGM-specific genomic resources are currently available.

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Bacterial colonization of the urogenital tract is limited by innate defenses, including the production of antimicrobial peptides (AMPs). Uropathogenic Escherichia coli (UPEC) resist AMP-killing to cause a range of urinary tract infections (UTIs) including asymptomatic bacteriuria, cystitis, pyelonephritis, and sepsis. UPEC strains have high genomic diversity and encode numerous virulence factors that differentiate them from non-UTI-causing strains, including ompT.

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Fibromyalgia (FM) is a prevalent syndrome, characterised by chronic widespread pain, fatigue, and impaired sleep, that is challenging to diagnose and difficult to treat. The microbiomes of 77 women with FM and that of 79 control participants were compared using 16S rRNA gene amplification and whole-genome sequencing. When comparing FM patients with unrelated controls using differential abundance analysis, significant differences were revealed in several bacterial taxa.

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Leishmania donovani is responsible for visceral leishmaniasis, a neglected and lethal parasitic disease with limited treatment options and no vaccine. The study of L. donovani has been hindered by the lack of a high-quality reference genome and this can impact experimental outcomes including the identification of virulence genes, drug targets and vaccine development.

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In the version of this article published, in the Online Methods eight citations to supplementary material refer to the wrong supplementary items. See the correction notice for full details.

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Background: The number of invasive group A (iGAS) infections due to hitherto extremely rare type strains has increased in several Canadian provinces since late 2015. We hypothesized that the cases recorded in the different provinces are linked and caused by strains of an clone that recently emerged and expanded explosively.

Methods: We analyzed both active and passive surveillance data for iGAS infections and used whole-genome sequencing to investigate the phylogenetic relationships of the strains responsible for these invasive infections country-wide.

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By analyzing multitissue gene expression and genome-wide genetic variation data in samples from a vervet monkey pedigree, we generated a transcriptome resource and produced the first catalog of expression quantitative trait loci (eQTLs) in a nonhuman primate model. This catalog contains more genome-wide significant eQTLs per sample than comparable human resources and identifies sex- and age-related expression patterns. Findings include a master regulatory locus that likely has a role in immune function and a locus regulating hippocampal long noncoding RNAs (lncRNAs), whose expression correlates with hippocampal volume.

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Vervet monkeys are among the most widely distributed nonhuman primates, show considerable phenotypic diversity, and have long been an important biomedical model for a variety of human diseases and in vaccine research. Using whole-genome sequencing data from 163 vervets sampled from across Africa and the Caribbean, we find high diversity within and between taxa and clear evidence that taxonomic divergence was reticulate rather than following a simple branching pattern. A scan for diversifying selection across taxa identifies strong and highly polygenic selection signals affecting viral processes.

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The gypsy moth, Lymantria dispar L., is one of the most destructive forest pests in the world. While the subspecies established in North America is the European gypsy moth (L.

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The Syst-OMICS consortium is sequencing 4,500 genomes and building an analysis pipeline for the study of genome evolution, antibiotic resistance and virulence genes. Metadata, including phenotypic as well as genomic data, for isolates of the collection are provided through the Foodborne Syst-OMICS database (SalFoS), at https://salfos.ibis.

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We report here the complete genome sequence of a panresistant strain, isolated from a patient with respiratory failure in Canada. No carbapenemase genes were identified. Carbapenem resistance is attributable to a frameshift in the gene; the basis for colistin resistance remains undetermined.

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Sequencing of the bla-carrying C. freundii B38 using the PacBio SMRT technique revealed that the genome contained a chromosome of 5,134,500 bp and three plasmids, pOZ172 (127,005 bp), pOZ181 (277,592 bp), and pOZ182 (18,467 bp). Plasmid pOZ172 was identified as IncFIIY, like pP10164-NDM and pNDM-EcGN174.

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Article Synopsis
  • * A specific GBS strain, NGBS375, has a unique genetic makeup, combining elements from different strains, which affects its virulence during infection.
  • * Although strain NGBS375 causes less severe infections compared to a more virulent strain, it has a similar ability to provoke an immune response, suggesting that its lower virulence is likely due to its limited growth and spread in the bloodstream.
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African green monkeys (AGMs) are natural primate hosts of simian immunodeficiency virus (SIV). Interestingly, features of the envelope-specific antibody responses in SIV-infected AGMs are distinct from that of HIV-infected humans and SIV-infected rhesus monkeys, including gp120-focused responses and rapid development of autologous neutralization. Yet, the lack of genetic tools to evaluate B-cell lineages hinders potential use of this unique non-human primate model for HIV vaccine development.

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Background: Clostridium difficile infection (CDI) is the leading infectious cause of nosocomial diarrhea. Hospitalized patients are at increased risk of developing CDI because they are exposed to C. difficile spores through contact with the hospital environment and often receive antibiotics and other medications that can disrupt the integrity of the indigenous intestinal microbiota and impair colonization resistance.

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  • Strains of serotype 2 Streptococcus suis cause infections in both pigs and humans, and this study explored genetic diversity within the common ST25 lineage using whole-genome sequencing.
  • The analysis of 51 strains from Canada, the U.S., and Thailand revealed significant genomic rearrangements and indicated that lateral gene transfer and recombination contribute to the genetic diversity of ST25.
  • The research identified two distinct clades corresponding to Thai and North American strains with unique antimicrobial resistance patterns and highlighted the limitations of multilocus sequence typing (MLST) for understanding S. suis evolution.
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Clustered regularly interspaced short palindromic repeats with CRISPR-associated gene (CRISPR-Cas) systems are widely recognized as critical genome defense systems that protect microbes from external threats such as bacteriophage infection. Several isolates of the intracellular pathogen Legionella pneumophila possess multiple CRISPR-Cas systems (type I-C, type I-F and type II-B), yet the targets of these systems remain unknown. With the recent observation that at least one of these systems (II-B) plays a non-canonical role in supporting intracellular replication, the possibility remained that these systems are vestigial genome defense systems co-opted for other purposes.

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