The role of Fusobacterium necrophorum in sheep and the environment in the severity and persistence of footrot

Ovine footrot is an infectious cause of lameness in sheep that has significant economic impact for the UK sheep farming industry. It is also a major concern for animal health and welfare. The causal agent is Dichelobacter nodosus, and Fusobacterium necrophorum is an opportunistic secondary pathogen that increases disease severity. The primary reservoirs for F. necrophorum in sheep were believed to be sheep faeces and the environment, however, no studies had demonstrated the presence of F. necrophorum at either of these sites. Two longitudinal studies (Study A and Study B) were conducted to determine reservoir sites of F. necrophorum in ovine footrot. Study A included 10 sheep sampled on four occasions at two week intervals. Study B included 40 sheep sampled weekly for 20 weeks. Samples collected from sheep and their environment were foot swabs, mouth swabs, faeces, soil and grass. Quantitative PCR was used to detect and quantify F. necrophorum. A multiple locus variable number tandem repeat analysis (MLVA) community typing scheme for F. necrophorum was developed and validated, and used to analyse samples from Study A and Study B. Contrary to prior assumption, the environment was not a significant reservoir of F. necrophorum. F. necrophorum persisted in sheep, primarily on feet with footrot. MLVA indicated that the strains of F. necrophorum found on the feet of sheep were closely related, and they may therefore share characteristics that make them well adapted to feet and footrot. Mouths and faeces were an intermittent reservoir for the strains of F. necrophorum involved in footrot. Mouths and faeces may therefore facilitate persistence of F. necrophorum in the absence of footrot, or facilitate transmission of F. necrophorum between flocks. Mouths were a persistent reservoir for strains of F. necrophorum not involved in footrot

“I didn’t see a sheep”: perspectives of lecturers and students at veterinary schools in Great Britain on learning about lameness in sheep

Introduction: Great Britain has over 15 million ewes. Lameness is one of the top three most economically important diseases for the sheep industry, costing about £80 million per annum. The prevalence of lameness reduced from 10% to 5% between 2004 and 2013 but further reduction is unlikely because many farmers and agricultural students still believe in, and use, ineffective practices to control lameness. Unfortunately, many veterinary practitioners consider themselves insufficiently knowledgeable to work confidently with sheep farmers, and many sheep farmers agree with them. Another route to improve control of lameness is to ensure that all new veterinary graduates are competent to advise farmers. Methods: Our study investigated how veterinary students are taught about management of lameness in sheep. Ten lecturers from eight veterinary schools were interviewed, and 33 students from four veterinary schools participated in four focus groups; all were recorded, transcribed, and analysed using directed qualitative content analysis. Results: Teaching time and opportunities for students to gain clinical experience of lameness were very limited. Students were not confident they could diagnose causes of lameness and listed many practices, including ineffective ones, to manage footrot. Discussion: We conclude that GB veterinary students are graduating without evidence-based understanding and clinical experience necessary to advise farmers on management of lameness in sheep. Given the importance of lameness in sheep in GB we conclude that an alternative approach to education on lameness in sheep could help to ensure that new graduate veterinarians can contribute to control of lameness in sheep

What are the Prospects of 3D Profiling Systems Applied to Firearms and Toolmark Identification?

This paper details a comparative pilot study of 3D (three dimensional) imaging technologies for potential application in forensic firearms and toolmark identification; as such it reviews the most up-to-date profiling systems. In particular, the paper focuses on the application of 3D imaging and recording technology as applied to firearm identification, being a specialised field within the discipline of toolmark identification. Each technology under test employs a different technique or scientific principle to capture topographic data i.e. focus-variation microscopy, confocal microscopy, point laser profilometry and vertical scanning interferometry. To qualitatively establish the capabilities and limitations of each technology investigated, standard reference samples were used and a set of specific operational criteria devised for successful application in this field. The reference standard crucially included and centred on was the National Institute of Standards and Technology (NIST) 'standard bullet'. This was to ensure that evaluation represented the practical examination of ballistic samples i.e. fired cartridge cases and bullets. It is concluded that focus-variation microscopy has potentially the most promising approach for a forensic laboratory instrument, in terms of functionality and 3D imaging performance, and is worthy of further investigation

Comparative genome mapping of the deer mouse (Peromyscus maniculatus) reveals greater similarity to rat (Rattus norvegicus) than to the lab mouse (Mus musculus)

<p>Abstract</p> <p>Background</p> <p>Deer mice (<it>Peromyscus maniculatus</it>) and congeneric species are the most common North American mammals. They represent an emerging system for the genetic analyses of the physiological and behavioral bases of habitat adaptation. Phylogenetic evidence suggests a much more ancient divergence of <it>Peromyscus </it>from laboratory mice (<it>Mus</it>) and rats (<it>Rattus</it>) than that separating latter two. Nevertheless, early karyotypic analyses of the three groups suggest <it>Peromyscus </it>to be exhibit greater similarities with <it>Rattus </it>than with <it>Mus</it>.</p> <p>Results</p> <p>Comparative linkage mapping of an estimated 35% of the deer mouse genome was done with respect to the Rattus and Mus genomes. We particularly focused on regions that span synteny breakpoint regions between the rat and mouse genomes. The linkage analysis revealed the Peromyscus genome to have a higher degree of synteny and gene order conservation with the Rattus genome.</p> <p>Conclusion</p> <p>These data suggest that: 1. the <it>Rattus </it>and <it>Peromyscus </it>genomes more closely represent ancestral Muroid and rodent genomes than that of <it>Mus</it>. 2. the high level of genome rearrangement observed in Muroid rodents is especially pronounced in <it>Mus</it>. 3. evolution of genome organization can operate independently of more commonly assayed measures of genetic change (e.g. SNP frequency).</p

Best practice versus farm practice: Perspectives of lecturers and students at agricultural colleges in England on management of lameness in sheep

We use the concepts of trust and knowledge to explore translation of scientific evidence about treatment of ovine footrot to students studying at agricultural colleges. We explore the role of different forms of trust (companion, competence and commitment) in facilitating relationships between students and informants. We also investigate how students acquire knowledge, and how this influences their practices for treating footrot. We find that despite being taught evidence-based practice (antibiotic treatment and no foot trimming) at college, most students would still use traditional farm practice (foot trimming) to treat footrot. Students develop tacit knowledge of traditional practices from farmers whilst working on sheep farms and these farmers have a strong influence on students' practices; students have high levels of companion trust for “known farmers". College lecturers who demonstrate competence gain students' trust, but where this does not occur there is a failure in communication between lecturer and student. Students acquire explicit classroom knowledge of evidence-based practice at college because there is limited practical experiential learning. This explicit knowledge is typically insufficient to change behaviour, unless students trust their lecturer. Our findings indicate that farming experience dominates over classroom experience and so college education alone will not ensure uptake of evidence-based practice

Distance tuneable integral membrane protein containing floating bilayers via in situ directed self-assembly

Model membranes allow for structural and biophysical studies on membrane biochemistry at the molecular level, albeit on systems of reduced complexity which can limit biological accuracy. Floating supported bilayers offer a means of producing planar lipid membrane models not adhered to a surface, which allows for improved accuracy compared to other model membranes. Here we communicate the incorporation of an integral membrane protein complex, the multidomain β-barrel assembly machinery (Bam), into our recently developed in situ self-assembled floating supported bilayers. Using neutron reflectometry and quartz crystal microbalance measurements we show this sample system can be fabricated using a two-step self-assembly process. We then demonstrate the complexity of the model membrane and tuneability of the membrane-to-surface distance using changes in the salt concentration of the bulk solution. Results demonstrate an easily fabricated, biologically accurate and tuneable membrane assay system which can be utilized for studies on integral membrane proteins within their native lipid matrix

Distance tuneable integral membrane protein containing floating bilayers via in situ directed self-assembly

Model membranes allow for structural and biophysical studies on membrane biochemistry at the molecular level, albeit on systems of reduced complexity which can limit biological accuracy. Floating supported bilayers offer a means of producing planar lipid membrane models not adhered to a surface, which allows for improved accuracy compared to other model membranes. Here we communicate the incorporation of an integral membrane protein complex, the multidomain β-barrel assembly machinery (Bam), into our recently developed in situ self-assembled floating supported bilayers. Using neutron reflectometry and quartz crystal microbalance measurements we show this sample system can be fabricated using a two-step self-assembly process. We then demonstrate the complexity of the model membrane and tuneability of the membrane-to-surface distance using changes in the salt concentration of the bulk solution. Results demonstrate an easily fabricated, biologically accurate and tuneable membrane assay system which can be utilized for studies on integral membrane proteins within their native lipid matrix