154 research outputs found

    A suggested new bacteriophage genus: “Viunalikevirus”

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    We suggest a bacteriophage genus, “Viunalikevirus”, as a new genus within the family Myoviridae. To date, this genus includes seven sequenced members: Salmonella phages ViI, SFP10 and ΦSH19; Escherichia phages CBA120 and PhaxI; Shigella phage phiSboM-AG3; and Dickeya phage LIMEstone1. Their shared myovirus morphology, with comparable head sizes and tail dimensions, and genome organization are considered distinguishing features. They appear to have conserved regulatory sequences, a horizontally acquired tRNA set and the probable substitution of an alternate base for thymine in the DNA. A close examination of the tail spike region in the DNA revealed four distinct tail spike proteins, an arrangement which might lead to the umbrella-like structures of the tails visible on electron micrographs. These properties set the suggested genus apart from the recently ratified subfamily Tevenvirinae, although a significant evolutionary relationship can be observed. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s00705-012-1360-5) contains supplementary material, which is available to authorized users

    Heritage Work: the Preservations and Performances of Thames Sailing Barges

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    ‘Heritage’ represents a series of contested and contingent relationships in the preservation and performance of the past. It is a relationship made all the more complex by taking into account the work that goes into both aspects: preserving what would otherwise be lost, and actively seeking public exposure and support. Work has been central to studies of heritage practices in the context of deindustrialisation: how working identities and communities use or become used in the development of heritage-led regeneration. This article examines what it is to engage in forms of work defined by their personal, community and commercial heritage appeal. It presents a study of those who live and work on Thames sailing barges – historic cargo vessels whose future survival relies on the impetus to preserve them as part of an industrial heritage, and in their fulfilment of a number of (often problematic) performative roles

    Genetically manipulated phages with improved pH resistance for oral administration in veterinary medicine

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    Orally administered phages to control zoonotic pathogens face important challenges, mainly related to the hostile conditions found in the gastrointestinal tract (GIT). These include temperature, salinity and primarily pH, which is exceptionally low in certain compartments. Phage survival under these conditions can be jeopardized and undermine treatment. Strategies like encapsulation have been attempted with relative success, but are typically complex and require several optimization steps. Here we report a simple and efficient alternative, consisting in the genetic engineering of phages to display lipids on their surfaces. Escherichia coli phage T7 was used as a model and the E. coli PhoE signal peptide was genetically fused to its major capsid protein (10A), enabling phospholipid attachment to the phage capsid. The presence of phospholipids on the mutant phages was confirmed by High Performance Thin Layer Chromatography, Dynamic Light Scattering and phospholipase assays. The stability of phages was analysed in simulated GIT conditions, demonstrating improved stability of the mutant phages with survival rates 102107 pfu.mL1 higher than wild-type phages. Our work demonstrates that phage engineering can be a good strategy to improve phage tolerance to GIT conditions, having promising application for oral administration in veterinary medicine.This work was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2013 unit and COMPETE 2020 (POCI-01-0145-FEDER-006684) and under the scope of the Project PTDC/BBB-BSS/6471/2014 (POCI-01-0145-FEDER-016678). Franklin L. Nobrega and Ana Rita Costa acknowledge FCT for grants SFRH/BD/86462/2012 and SFRH/BPD/94648/2013, respectively. Melvin F. Siliakus acknowledges funding from the Biobased Ecologically Balanced Sustainable Industrial Chemistry (BE-BASIC) foundation. Electron microscopy work was performed at the Wageningen Electron Microscopy Centre (WEMC) of Wageningen University

    The Embodied and Situated Nature of Moods

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    This is the final version of the article. Available from Springer via the DOI in this record.In this paper I argue that it is misleading to regard the brain as the physical basis or “core machinery” of moods. First, empirical evidence shows that brain activity not only influences, but is in turn influenced by, physical activity taking place in other parts of the organism (such as the endocrine and immune systems). It is therefore not clear why the core machinery of moods ought to be restricted to the brain. I propose, instead, that moods should be conceived as embodied, i.e., their physical basis should be enlarged so as to comprise not just brain but also bodily processes. Second, I emphasise that moods are also situated in the world. By this I do not simply mean that moods are influenced by the world, but that they are complexly interrelated with it, in at least three different ways: they are shaped by cultural values and norms; they are materially and intersubjectively “scaffolded”; and they can even “experientially incorporate” parts of the world, i.e., include the experience of parts of the world as part of oneself

    Enumeration and Diversity of Campylobacters and Bacteriophages Isolated during the Rearing Cycles of Free-Range and Organic Chickens

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    Campylobacters and Campylobacter-specific bacteriophages were isolated and enumerated during the rearing cycle of free-range (56 days) and organic chickens (73 days) at 3-day intervals from hatching until slaughter. In both flocks Campylobacter jejuni was the initial colonizer but Campylobacter coli was detected more frequently from 5 weeks of age. The diversity of the Campylobacter isolates was examined by pulsed-field gel electrophoresis of SmaI-digested genomic DNA and antimicrobial resistance typing. Bacteriophages were isolated from 51% (19 of 37 birds) of Campylobacter-positive organic birds (log(10) 2.5 to log(10) 5.7 PFU/g of cecal contents). The bacteriophages were all typical group III Campylobacter bacteriophages in terms of genomic size but could be characterized in terms of their host range and placed into five different groups. In contrast to the organic birds, anti-Campylobacter activity (bacteriocin-like) was observed in 26% (10 of 38 birds) of Campylobacter-positive free-range birds, and only one bacteriophage was isolated. Appearance of either bacteriophages or anti-Campylobacter activity was associated with changes in the levels of colonization and the predominant genotypes and species isolated. The frequency and potential influence of naturally occurring bacteriophages and/or inhibitory substances on the diversity and fluctuations of populations of campylobacters have not previously been reported in either free-range or organic chickens

    Bacteriophage Therapy To Reduce Campylobacter jejuni Colonization of Broiler Chickens

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    Colonization of broiler chickens by the enteric pathogen Campylobacter jejuni is widespread and difficult to prevent. Bacteriophage therapy is one possible means by which this colonization could be controlled, thus limiting the entry of campylobacters into the human food chain. Prior to evaluating the efficacy of phage therapy, experimental models of Campylobacter colonization of broiler chickens were established by using low-passage C. jejuni isolates HPC5 and GIIC8 from United Kingdom broiler flocks. The screening of 53 lytic bacteriophage isolates against a panel of 50 Campylobacter isolates from broiler chickens and 80 strains isolated after human infection identified two phage candidates with broad host lysis. These phages, CP8 and CP34, were orally administered in antacid suspension, at different dosages, to 25-day-old broiler chickens experimentally colonized with the C. jejuni broiler isolates. Phage treatment of C. jejuni-colonized birds resulted in Campylobacter counts falling between 0.5 and 5 log(10) CFU/g of cecal contents compared to untreated controls over a 5-day period postadministration. These reductions were dependent on the phage-Campylobacter combination, the dose of phage applied, and the time elapsed after administration. Campylobacters resistant to bacteriophage infection were recovered from phage-treated chickens at a frequency of <4%. These resistant types were compromised in their ability to colonize experimental chickens and rapidly reverted to a phage-sensitive phenotype in vivo. The selection of appropriate phage and their dose optimization are key elements for the success of phage therapy to reduce campylobacters in broiler chickens

    A biocontrol option to control a foodborne pathogen, using bacteriophages to control Campylobacter in poultry

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    Campylobacter is a leading cause of foodborne illnesses both in Australia and internationally, and is frequently found in poultry. There is a need for sustainable options to support current farm management strategies that address food-safety. The use of bacteriophages provides a safe biocontrol option. A collaborative study by the Department of Agriculture and Fisheries (QLD), the University of Nottingham (UK) and the Institute of Environmental Science and Research (NZ) is focused on the control of Campylobacter in broiler chickens. Campylobacter bacteriophages were sourced from Queensland poultry farms and following extensive screening, suitable candidates to be used in cocktails were identified. This followed an on-farm proof of concept study on a small sample of chickens, using selected cocktail candidates, to provide an understanding of the hurdles for practical application. The trial demonstrated a 2-log CFU/g reduction of Campylobacter in the caeca of treated birds compared to non-treated (p < 0.05). Another important finding of this study was the absence of bacteriophage resistance, a concern with phage therapy. Work at ESR has addressed approaches to select and adapt bacteriophage cocktails to particular hosts, which included screening against NZ and Australian hosts. This approach enabled the formulation of high performing bacteriophage cocktails for Australian and international markets. Work in the UK is exploring the understanding of the host-bacteriophage relationships to ensure safety to meet regulatory requirements and support potential scale-up options. In summary, the work in progress via international collaborations is aimed at delivering a safe biocontrol option that can meet both commercial and regulatory needs aiming at controlling on-farm Campylobacter
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