Individual animal tests for ovine Johne's disease.

Routine diagnostic tests for ovine paratuberculosis have poor sensitivity in the early stages of the disease, and transmission often occurs before detection. Currently there are no tests to accurately confirm early infection in individual sheep. Such tests are required to provide trading opportunities for producers who may have valuable stock at low risk of infection. Surgical biopsy is one means of disease detection using relatively sensitive laboratory procedures, but was unproven. 77 sheep grazing on a heavily infected farm were examined at 12, 18 and 24 months of age by histopathology and culture of biopsied ileum and mesenteric lymph nodes. Results from biopsy were compared to those from routine tests (ELISA, AGID, IFN-γ, skin testing, faecal culture and direct PCR) applied at six-monthly intervals, and to necropsy findings at three years of age. A total of 170 biopsies were performed without serious complications, and the samples collected were adequate for culture and histological assessment of paratuberculosis. Overall, 36% of sheep were shown to be uninfected at 3 years of age. Of these, 16 were uninfected at all sampling times and 11 sheep had recovered. (ie. They had been infected at an earlier sampling.) The remaining 64% of sheep were classified at necropsy as infected. Biopsy was consistently the most sensitive nonlethal technique for identification of infected sheep, although even at 36 months it detected only 2/3 of infected sheep. It may be useful as an additional tool in the management for individual valuable sheep from infected stud flocks

Evaluation of the limitations and methods to improve rapid phage-based detection of viable Mycobacterium avium subsp. paratuberculosis in the blood of experimentally infected cattle

Background Disseminated infection and bacteraemia is an underreported and under-researched aspect of Johne’s disease. This is mainly due to the time it takes for Mycobacterium avium subsp. paratuberculosis (MAP) to grow and lack of sensitivity of culture. Viable MAP cells can be detected in the blood of cattle suffering from Johne’s disease within 48 h using peptide-mediated magnetic separation (PMMS) followed by bacteriophage amplification. The aim of this study was to demonstrate the first detection of MAP in the blood of experimentally exposed cattle using the PMMS-bacteriophage assay and to compare these results with the immune response of the animal based on serum ELISA and shedding of MAP by faecal culture. Results Using the PMMS-phage assay, seven out of the 19 (37 %) MAP-exposed animals that were tested were positive for viable MAP cells although very low numbers of MAP were detected. Two of these animals were positive by faecal culture and one was positive by serum ELISA. There was no correlation between PMMS-phage assay results and the faecal and serum ELISA results. None of the control animals (10) were positive for MAP using any of the four detection methods. Investigations carried out into the efficiency of the assay; found that the PMMS step was the limiting factor reducing the sensitivity of the phage assay. A modified method using the phage assay directly on isolated peripheral blood mononuclear cells (without PMMS) was found to be superior to the PMMS isolation step. Conclusions This proof of concept study has shown that viable MAP cells are present in the blood of MAP-exposed cattle prior to the onset of clinical signs. Although only one time point was tested, the ability to detect viable MAP in the blood of subclinically infected animals by the rapid phage-based method has the potential to increase the understanding of the pathogenesis of Johne’s disease progression by warranting further research on the presence of MAP in blood

A review of the impact of food design on the mealtimes of people with swallowing disability who require texture-modified food

Texture-modified foods are a common component of interventions provided to people with dysphagia (swallowing disorders) to maintain their respiratory health, nutritional health and to reduce the risk of aspiration-related illness or choking on food. However, the unsightly and unappetizing appearance of texture-modified foods may negatively impact on the mealtime experience and acceptance of texture-modified foods of persons with dysphagia. The aim of this review was to determine what is known about the impact of specific elements of food design – food struc-ture and visual appeal – on the mealtime experiences of people with dysphagia. This review of 35 studies presents evidence on how the physical characteristics of texture-modified foods for people with dysphagia can be considered during food production, formulation or service to improve their mealtime experience. Overall, the visual appeal, texture, taste, aroma, temperature, mealtime environment and mealtime assistance all impact upon mealtime experiences and should be considered carefully in the design of a person’s mealtime plan and food-related dysphagia interventions to improve their mealtime-related quality of life. Further research needs to include the views of people with dysphagia, particularly those with life-long conditions, who might require texture-modified food for an extended period over their lifespan

Full Genome Characterization of the Culicoides-Borne Marsupial Orbiviruses: Wallal Virus, Mudjinbarry Virus and Warrego Viruses

Viruses belonging to the species Wallal virus and Warrego virus of the genus Orbivirus were identified as causative agents of blindness in marsupials in Australia during 1994/5. Recent comparisons of nucleotide (nt) and amino acid (aa) sequences have provided a basis for the grouping and classification of orbivirus isolates. However, full-genome sequence data are not available for representatives of all Orbivirus species. We report full-genome sequence data for three additional orbiviruses: Wallal virus (WALV); Mudjinabarry virus (MUDV) and Warrego virus (WARV). Comparisons of conserved polymerase (Pol), sub-core-shell 'T2' and core-surface 'T13' proteins show that these viruses group with other Culicoides borne orbiviruses, clustering with Eubenangee virus (EUBV), another orbivirus infecting marsupials. WARV shares <70% aa identity in all three conserved proteins (Pol, T2 and T13) with other orbiviruses, consistent with its classification within a distinct Orbivirus species. Although WALV and MUDV share <72.86%/67.93% aa/nt identity with other orbiviruses in Pol, T2 and T13, they share >99%/90% aa/nt identities with each other (consistent with membership of the same virus species - Wallal virus). However, WALV and MUDV share <68% aa identity in their larger outer capsid protein VP2(OC1), consistent with membership of different serotypes within the species - WALV-1 and WALV-2 respectively

Encephalomyocarditis virus may use different pathways to initiateinfection of primary human cardiomyocytes

Encephalomyocarditis virus (EMCV) caninfect a wide range of vertebrate species including swineand non-human primates, but few data are available forhumans. We therefore wanted to gain further insight intothe mechanisms involved in EMCV infection of humancells. For this purpose, we analyzed the permissiveness ofprimary human cardiomyocytes towards two strains ofEMCV; a pig myocardial strain (B279/95) and a rat strain(1086C). In this study, we show that both strains productivelyinfect primary human cardiomyocytes and inducecomplete cytolysis. Binding and infection inhibitionexperiments indicated that attachment and infection areindependent of sialic acid and heparan sulfate for B279/95and dependent for 1086C. Sequence comparison betweenthe two strains and three-dimensional analysis of the capsidrevealed that six of the seven variable residues are surfaceexposed,suggesting a role for these amino acids in binding.Moreover, analysis of variants isolated from the 1086Cstrain revealed the importance of lysine 231 of VP1 in theattachment of EMCV to cell-surface sialic acid residues.Together, these results show a potential for EMCV strainsto use at least two different binding possibilities to initiateinfection and provide new insights into the mechanismsinvolved in primary human cell recognition by EMCV

Encephalomyocarditis virus infection in an Italian zoo

A fatal Encephalomyocarditis virus (EMCV) infection epidemic involving fifteen primates occurred between October 2006 and February 2007 at the Natura Viva Zoo. This large open-field zoo park located near Lake Garda in Northern Italy hosts one thousand animals belonging to one hundred and fifty different species, including various lemur species. This lemur collection is the most relevant and rich in Italy. A second outbreak between September and November 2008 involved three lemurs. In all cases, the clinical signs were sudden deaths generally without any evident symptoms or only with mild unspecific clinical signs. Gross pathologic changes were characterized by myocarditis (diffuse or focal pallor of the myocardium), pulmonary congestion, emphysema, oedema and thoracic fluid. The EMCV was isolated and recognized as the causative agent of both outbreaks. The first outbreak in particular was associated with a rodent plague, confirming that rats are an important risk factor for the occurrence of the EMCV infection