Immunity,safety and protection of an Adenovirus 5 prime - Modified Vaccinia virus Ankara boost subunit vaccine against Mycobacterium avium subspecies paratuberculosis infection in calves

Vaccination is the most cost effective control measure for Johne’s disease caused by Mycobacterium avium subspecies paratuberculosis (MAP) but currently available whole cell killed formulations have limited efficacy and are incompatible with the diagnosis of bovine tuberculosis by tuberculin skin test. We have evaluated the utility of a viral delivery regimen of non-replicative human Adenovirus 5 and Modified Vaccinia virus Ankara recombinant for early entry MAP specific antigens (HAV) to show protection against challenge in a calf model and extensively screened for differential immunological markers associated with protection. We have shown that HAV vaccination was well tolerated, could be detected using a differentiation of infected and vaccinated animals (DIVA) test, showed no cross-reactivity with tuberculin and provided a degree of protection against challenge evidenced by a lack of faecal shedding in vaccinated animals that persisted throughout the 7 month infection period. Calves given HAV vaccination had significant priming and boosting of MAP derived antigen (PPD-J) specific CD4⁺, CD8⁺ IFN-γ producing T-cell populations and, upon challenge, developed early specific Th17 related immune responses, enhanced IFN-γ responses and retained a high MAP killing capacity in blood. During later phases post MAP challenge, PPD-J antigen specific IFN-γ and Th17 responses in HAV vaccinated animals corresponded with improvements in peripheral bacteraemia. By contrast a lack of IFN-γ, induction of FoxP3+ T cells and increased IL-1β and IL-10 secretion were indicative of progressive infection in Sham vaccinated animals. We conclude that HAV vaccination shows excellent promise as a new tool for improving control of MAP infection in cattle.

Electronic supplementary material

The online version of this article (doi:10.1186/s13567-014-0112-9) contains supplementary material, which is available to authorized users.     

Molecular epidemiology of environmental MRSA at an equine teaching hospital: introduction,circulation and maintenance

The role that environmental contamination might play as a reservoir and a possible source of Methicillin-resistant Staphylococcus aureus (MRSA) for patients and personnel at equine veterinary hospitals remains undefined, as the environment has only been monitored during outbreaks or for short periods. Therefore, the objectives of this study were to determine the monthly presence, distribution, and characteristics of environmental MRSA at an equine hospital, and to establish patterns of contamination over time using molecular epidemiological analyses. For this purpose, a yearlong active MRSA surveillance was performed targeting the environment and incoming patients. Antimicrobial susceptibility testing, SCCmec typing, PFGE typing, and dendrographic analysis were used to characterize and analyze these isolates. Overall, 8.6% of the surfaces and 5.8% of the horses sampled were positive for MRSA. The most common contaminated surfaces were: computers, feed-water buckets, and surgery tables-mats. Ninety percent of the isolates carried SCCmec type IV, and 62.0% were classified as USA500. Molecular analysis showed that new pulsotypes were constantly introduced into the hospital throughout the year. However, maintenance of strains in the environment was also observed when unique clones were detected for 2 consecutive months on the same surfaces. Additionally, pulsotypes were circulating throughout several areas and different contact surfaces of the hospital. Based on these results, it is evident that MRSA is constantly introduced and frequently found in the equine hospital environment, and that some contact surfaces could act as “hot-spots”. These contaminated surfaces should be actively targeted for strict cleaning and disinfection as well as regular monitoring.     

A PROPOSED RADIOGRAPHIC CLASSIFICATION SCHEME FOR CONGENITAL THORACIC VERTEBRAL MALFORMATIONS IN BRACHYCEPHALIC “SCREW‐TAILED” DOG BREEDS

Congenital vertebral malformations are common in brachycephalic “screw‐tailed” dog breeds such as French bulldogs, English bulldogs, Boston terriers, and pugs. The aim of this retrospective study was to determine whether a radiographic classification scheme developed for use in humans would be feasible for use in these dog breeds. Inclusion criteria were hospital admission between September 2009 and April 2013, neurologic examination findings available, diagnostic quality lateral and ventro‐dorsal digital radiographs of the thoracic vertebral column, and at least one congenital vertebral malformation. Radiographs were retrieved and interpreted by two observers who were unaware of neurologic status. Vertebral malformations were classified based on a classification scheme modified from a previous human study and a consensus of both observers. Twenty‐eight dogs met inclusion criteria (12 with neurologic deficits, 16 with no neurologic deficits). Congenital vertebral malformations affected 85/362 (23.5%) of thoracic vertebrae. Vertebral body formation defects were the most common (butterfly vertebrae 6.6%, ventral wedge‐shaped vertebrae 5.5%, dorsal hemivertebrae 0.8%, and dorso‐lateral hemivertebrae 0.5%). No lateral hemivertebrae or lateral wedge‐shaped vertebrae were identified. The T7 vertebra was the most commonly affected (11/28 dogs), followed by T8 (8/28 dogs) and T12 (8/28 dogs). The number and type of vertebral malformations differed between groups (P = 0.01). Based on MRI, dorsal, and dorso‐lateral hemivertebrae were the cause of spinal cord compression in 5/12 (41.6%) of dogs with neurologic deficits. Findings indicated that a modified human radiographic classification system of vertebral malformations is feasible for use in future studies of brachycephalic “screw‐tailed” dogs.     

Relationships between littoral microcrustacea and aquatic macrophyte communities on the Isle of Skye (Scotland), with implications for the conservation of standing waters

Littoral microcrustacean (Ctenopoda, Anomopoda, Onchyopoda) samples, aquatic macrophyte data and chemical measurements were collected from 51 freshwater lochs in the Isle of Skye, Scotland, during the summer of 1989. Canonical correspondence analysis was employed to investigate correlations between the environmental data, the microcrustacean assemblages, and the aquatic macrophyte community types used for floristic classification of standing waters. Cluster analysis was used to classify lochs based on their microcrustacean assemblages. The major trends in microcrustacean distributions were related to pH, catchment area, macrophyte diversity and the distance from the sea. There was little correlation between the plant community types and microcrustacean assemblages. These results support the case for the development of an integrated approach to lake surveys so that correlations can be made between environmental variables and the distribution and abundance patterns of the plant and animal taxa of conservation interest.     

Nasopharyngeal myxosarcoma in a Bengal tiger (Panthera tigris).

An 18- to 25-yr-old intact female Bengal tiger (Panthera tigris) was diagnosed antemortem and postmortem with nasopharyngeal myxosarcoma metastatic to the lung, chronic lymphoplasmacytic otitis media, and lymphoplasmacytic and eosinophilic stomatitis. Myxosarcomas are rare in domestic animals and seldom metastasize; this tumor has not been previously reported in an exotic felid. Computed tomography of the skull was used during the diagnoses.     

Toll-like receptor 3 (TLR3): a new marker of canine monocytes-derived dendritic cells (cMo-DC)

Toll-like receptors (TLRs) are a family of functionally important receptors for recognition of pathogen-associated molecular pattern (PAMP) since they trigger the pro-inflammatory response and upregulation of costimulatory molecules, linking the rapid innate response to adaptative immunity. In human leukocytes, TLR3 has been found to be specifically expressed in dendritic cells (DC). This study examined the expression of TLR3 in canine monocytes-derived DC (cMo-DC) and PBMC using three new anti-TLR3 mAbs (619F7, 722E2 and 713E4 clones). The non-adherent cMo-DC generated after culture in canine IL-4 plus canine GM-CSF were labelled with the three anti-TLR3 clones by flow cytometry, with a strong expression shown for 619F7 and 722E2 clones. By contrast, TLR3 expression was low to moderate in canine monocytes and lymphocytes. These results were confirmed by Western blot using 619F7 and 722E2 clones and several polypeptide bands were observed, suggesting a possible cleavage of TLR3 molecule or different glycosylation states. In addition, TLR3 was detectable in immunocytochemistry by using 722E2 clone. In conclusion, this first approach to study canine TLR3 protein expression shows that three anti-TLR3 clones detect canine TLR3 and can be used to better characterize canine DC and the immune system of dogs.     

Molecular biology of male gametogenesis

Pollen development has been studied at a molecular level in several systems that are amenable to genetic or transgenic analysis. We have characterized several tomato genes that are expressed late in pollen development. Our goals in this research were 1) to determine the cis- and tran-acting factors that mediate pollen expression, and 2) to determine the functions of the proteins encoded by these genes. We currently favor the hypothesis that pollen-specific gene expression is mediated in a combinatorial manner. Antisense experiments have indicated an important role for the LAT52 protein during pollen hydration.     

Comparative efficiencies of isopropyl and tert-butyl alcohols for extracting zeins from maize endosperm

Protein of endosperm of maize grains originating from three wild-type inbreds and their opaque-2 versions were solubilized in diverse extracts (E) by the sequential use of 0.5 M NaCl, water (E(1,2)), alcohol plus a reducing agent (E(3)), and salt plus a reducing agent (E(4)). Zeins were isolated in extracts E(3) and E(4) obtained by using 55% (w/w) isopropyl alcohol (i-PrOH) + 0.2% dithiothreitol (DTT) followed by 0.5 M NaCl + 0.2% DTT buffered at pH 10 or 60% tert-butyl alcohol (t-BuOH) + 0.2% DTT followed by 0.5% sodium acetate + 0.2% DTT in 30% t-BuOH. For a given genotype the percentage of extracted zeins was independent of the nature of the alcohol. The latter had a slight effect on the respective magnitude of E(3) and E(4): E(3) increased at the expense of E(4) when t-BuOH was substituted to i-PrOH for their isolation. The percentage of the total endosperm nitrogen present in E(3) + E(4) was identical to that of fractions F(II) + F(III) + F(IV) isolated according to the classical Landry-Moureaux extraction procedure. SDS-PAGE analysis revealed the presence of all types of zeins (alpha, beta, gamma, and delta) in E(3) and F(III), residual zeins in E(4) isolated with t-BuOH, and streaking only in E(4) and F(IV) isolated with NaCl at pH 10. The data together with those of the literature were discussed with regard to the influence of procedure on the yield of zeins using alcoholic extraction.     

Do multipurpose companion trees affect high value timber trees in a silvopastoral plantation system?

Establishment of native timber trees on deforested land may contribute to the livelihood of farmers, to improved ecosystem services and to increased greenhouse gas uptake. Here, we present a new silvopastoral planting design to assess species performance and interspecific competition or facilitation effects among native timber and multipurpose trees in Central America. Two timber species, Tabebuia rosea and Cedrela odorata, were established in three low-density planting regimes allowing combined tree and future livestock production: (1) solitary planting, (2) companion planting with Guazuma ulmifolia, and (3) companion planting with the nitrogen-fixing Gliricidia sepium. We quantified survival, growth and reforestation potential of the two timber species subjected to the different planting regimes for the first 2 years after establishment. Nitrogen concentration as well as stable nitrogen and carbon isotope composition (δ¹⁵N, δ¹³C) of leaves of the timber saplings were determined. T. rosea showed higher survival and better growth than C. odorata under varying environmental conditions (soil, concomitant vegetation). Performance of the timber saplings was unaffected by either companion species. Planting regimes had no effect on foliar nitrogen concentration and δ¹⁵N of the two timber species, although δ¹⁵N values indicated nitrogen fixation activity in G. sepium trees. Planting regimes affected foliar δ¹³C values in T. rosea. δ¹³C values were significantly higher in solitarily growing individuals, suggesting lower exposition to water stress conditions in saplings surrounded by companion species. As we found positively correlated growth traits among timber and multipurpose trees, a combined planting may benefit farmers by providing additional goods and services.     

Temperature signals contribute to the timing of photoperiodic growth cessation and bud set in poplar

Bud set, the cornerstone delimiting the seasonal growth period in trees, is the dynamic net result of the often photoperiod-controlled growth cessation and the subsequent bud formation. Here, we show that in hybrid poplar, the critical day length for growth cessation and the duration of bud formation each vary with local climatic conditions in identical genotypes. The detailed dissection of bud set suggests temperature as one additional environmental factor that modifies the sensitivity to day-length signals at growth cessation and influences the duration of bud formation in poplar. The ability of perennial plants to integrate additional environmental signals with photoperiod signaling may add to short-term acclimatization to the predicted longer growing seasons in future climates.