Publications by authors named "Valerie E Paquet"

Background/objectives: Antibiotic resistance gene (ARG) spread is driven by horizontal gene transfer (HGT). Ciliated protozoa may contribute to this process, as their predation has been shown to facilitate HGT in certain bacteria. Here, this phenomenon was further investigated using subsp.

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The genus Flavobacterium comprises a diversity of species, including fish pathogens. Multiple techniques have been used to identify isolates of this genus, such as phenotyping, polymerase chain reaction genotyping, and in silico whole-genome taxonomy. In this study, we demonstrate that whole-genome-based taxonomy, using average nucleotide identity and molecular phylogeny, is the most accurate approach for Flavobacterium species.

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is a genus of microorganisms living in a variety of hosts and habitats across the globe. Some species are found in fish organs, and only a few, such as and , cause severe disease and losses in fish farms. The evolution of flavobacteria that are pathogenic to fish is unknown, and the protein changes accountable for the selection of their colonization to fish have yet to be determined.

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Article Synopsis
  • The study investigates the predation resistance of Aeromonas salmonicida using Dictyostelium discoideum as a host, focusing on new mesophilic isolates from Alberta, Canada.
  • Results show that while some mesophilic isolates display strong resistance to the amoeba DH1-10, they struggle against a more aggressive strain, AX2.
  • Phylogenetic analysis reveals that new isolates cluster with strains from Argentina, India, and Spain, highlighting significant diversity among mesophilic strains across different regions.
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The bacterium causes porcine exudative epidermitis in piglets, which represents both health and welfare concerns. Few genome sequences of this pathogen are published. We provide four additional ones to help future genomic analysis of .

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Aeromonas salmonicida subsp. salmonicida is a Gam-negative bacterium responsible for furunculosis in fish. Because this aquatic bacterial pathogen has a rich reservoir of antibiotic-resistant genes, it is essential to investigate antibacterial alternatives, including the use of phages.

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Plasmids that carry antibiotic resistance genes occur frequently in subsp. , an aquatic pathogen with severe consequences in salmonid farming. Here, we describe a 67 kb plasmid found in the subsp.

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All the 36 known species to date of the genus are mesophilic except the species , which includes both psychrophilic and mesophilic subspecies. For 20 years, more and more mesophilic strains have been discovered. Only subsp.

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Aeromonas salmonicida subsp. salmonicida causes furunculosis, a major infection that affects fish farms worldwide. We isolated phage vB_AsaM_LPM4 (LPM4) from a diseased fish.

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subsp. is a pathogenic bacterium responsible for furunculosis in salmonids. Following an outbreak of furunculosis, the infection can be treated with antibiotics, but it is common to observe ineffective treatment due to antibiotic resistance.

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Antimicrobial resistance (AMR) is continuing to grow across the world. Though often thought of as a mostly public health issue, AMR is also a major agricultural and environmental problem. As such, many researchers refer to it as the preeminent One Health issue.

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Worldwide, Aeromonas salmonicida is a major bacterial pathogen of fish in both marine and freshwater environments. Despite psychrophilic growth being common for this species, the number of characterized mesophilic strains is increasing. Thus, this species may serve as a model for the study of intraspecies lifestyle diversity.

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Aquaculture is a rapidly growing food production sector. Fish farmers are experiencing increasing problems with antibiotic resistance when fighting against pathogenic bacteria such as subsp. , the causative agent of furunculosis.

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Aeromonas salmonicida subspecies salmonicida, a fish pathogen, expresses various virulence factors such as an A-layer, lipases and proteases during the infection process. Not all strains of this bacterium express the same virulence factors. It is important to be able to evaluate which factors are present when characterizing strains.

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The genome sequencing of subspecies strain 2004-072 revealed a plasmid bearing a region carrying antibiotic resistance genes very similar to the one found in the plasmid pRAS1, an IncU family plasmid. This new plasmid was named pRAS1b.

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Genomic islands (Aeromonas salmonicida genomic islands, AsaGEIs) are found worldwide in many isolates of Aeromonas salmonicida subsp. salmonicida, a fish pathogen. To date, five variants of AsaGEI (1a, 1b, 2a, 2b and 2c) have been described.

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The type three secretion system (TTSS) locus of subsp. , located on the plasmid pAsa5, is known to be lost when the bacterium is grown at temperatures of 25 °C. The loss of the locus is due to the recombination of the insertion sequences flanking the TTSS region.

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Aeromonas salmonicida strains cause problematic bacterial infections in the aquaculture industry worldwide. The genus Aeromonas includes both mesophilic and psychrophilic species. Bacteriophages that infect Aeromonas spp.

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Protozoa are natural predators of bacteria, but some bacteria can evade digestion once phagocytosed. Some of these resistant bacteria can be packaged in the fecal pellets produced by protozoa, protecting them from physical stresses and biocides. Depending on the bacteria and protozoa involved in the packaging process, pellets can have different morphologies.

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The bacterial species officially has five subspecies. A large majority of the currently available sequences come from subsp. , which causes furunculosis in salmonids.

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The Gram-negative bacterium Aeromonas salmonicida subsp. salmonicida is an aquatic pathogen which causes furunculosis to salmonids, especially in fish farms. The emergence of strains of this bacterium exhibiting antibiotic resistance is increasing, limiting the effectiveness of antibiotherapy as a treatment against this worldwide disease.

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Aeromonas salmonicida subsp. salmonicida is a fish pathogen that causes furunculosis. Antibiotherapy used to treat furunculosis in fish has led to resistance.

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Mycobacteria are widespread microorganisms that live in various environments, including man-made water systems where they cohabit with protozoa. Environmental mycobacterial species give rise to many opportunistic human infections and can infect phagocytic protozoa. Protozoa such as amoebae and ciliates feeding on bacteria can sometimes get rid of non-digestible or pathogenic material by packaging it into secreted fecal pellets.

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The amoeba Dictyostelium discoideum produces and secretes multilamellar bodies (MLBs) mainly composed of amoebal membranes upon digestion of bacteria. After their secretion, the fate of these MLBs remains unknown. The aim of this study was to determine if protozoa can internalize and digest secreted D.

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Phages infecting Aeromonas salmonicida subsp. salmonicida, the causative agent of the fish disease furunculosis, have been isolated for decades but very few of them have been characterized. Here, the host range of 12 virulent phages, including three isolated in the present study, was evaluated against a panel of 65 A.

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