Diseases In Livestock Animals Research Articles

Genetic engineering of Salmonella spp. for novel vaccine strategies and therapeutics.

Salmonella enterica is a diverse species that infects both humans and animals. S. enterica subspecies enterica consists of more than 1,500 serovars. Unlike typhoidal Salmonella serovars which are human host-restricted, non-typhoidal Salmonella (NTS) serovars are associated with foodborne illnesses worldwide and are transmitted via the food chain. Additionally, NTS serovars can cause disease in livestock animals causing significant economic losses. Salmonella is a well-studied model organism that is easy to manipulate and evaluate in animal models of infection. Advances in genetic engineering approaches in recent years have led to the development of Salmonella vaccines for both humans and animals. In this review, we focus on current progress of recombinant live-attenuated Salmonella vaccines, their use as a source of antigens for parenteral vaccines, their use as live-vector vaccines to deliver foreign antigens, and their use as therapeutic cancer vaccines in humans. We also describe development of live-attenuated Salmonella vaccines and live-vector vaccines for use in animals.

A High-Throughput Phenotypic Screen of the 'Pandemic Response Box' Identifies a Quinoline Derivative with Significant Anthelmintic Activity.

Parasitic nematodes cause diseases in livestock animals and major economic losses to the agricultural industry worldwide. Nematodes of the order Strongylida, including Haemonchus contortus, are particularly important. The excessive use of anthelmintic compounds to treat infections and disease has led to widespread resistance to these compounds in nematodes, such that there is a need for new anthelmintics with distinctive mechanisms of action. With a focus on discovering new anthelmintic entities, we screened 400 chemically diverse compounds within the ‘Pandemic Response Box’ (from Medicines for Malaria Venture, MMV) for activity against H. contortus and its free-living relative, Caenorhabditis elegans—a model organism. Using established phenotypic assays, test compounds were evaluated in vitro for their ability to inhibit the motility and/or development of H. contortus and C. elegans. Dose-response evaluations identified a compound, MMV1581032, that significantly the motility of H. contortus larvae (IC50 = 3.4 ± 1.1 μM) and young adults of C. elegans (IC50 = 7.1 ± 4.6 μM), and the development of H. contortus larvae (IC50 = 2.2 ± 0.7 μM). The favourable characteristics of MMV1581032, such as suitable physicochemical properties and an efficient, cost-effective pathway to analogue synthesis, indicates a promising candidate for further evaluation as a nematocide. Future work will focus on a structure-activity relationship investigation of this chemical scaffold, a toxicity assessment of potent analogues and a mechanism/mode of action investigation.

Salmonella Vaccine Vector System for Foot-and-Mouth Disease Virus and Evaluation of Its Efficacy with Virus-Like Particles.

Foot-and-mouth disease virus (FMDV) causes a highly contagious and devastating disease in livestock animals and has a great potential to cause severe economic loss worldwide. The major antigen of FMDV capsid protein, VP1, contains the major B-cell epitope responsible for effectively eliciting protective humoral immunity. In this study, irradiated Salmonella Typhimurium (KST0666) were used as transgenic vectors containing stress-inducible plasmid pRECN-VP1 to deliver the VP1 protein from FMDV-type A/WH/CHA/09. Mice were orally inoculated with ATOMASal-L3 harboring pRECN-VP1, and FMDV virus-like particles, where (VLPFMDV)-specific humoral, mucosal, and cellular immune responses were evaluated. Mice vaccinated with attenuated Salmonella (KST0666) expressing VP1 (named KST0669) showed high levels of VLP-specific IgA in feces and IgG in serum, with high FMDV neutralization titer. Moreover, KST0669-vaccinated mice showed increased population of IFN-γ (type 1 T helper cells; Th1 cells)-, IL-5 (Th2 cells)-, and IL-17A (Th17 cells)-expressing CD4+ as well as activated CD8+ T cells (IFN-γ+CD8+ cells), detected by stimulating VLPFMDV. All data indicate that our Salmonella vector system successfully delivered FMDV VP1 to immune cells and that the humoral and cellular efficacy of the vaccine can be easily evaluated using VLPFMDV in a Biosafety Level I (BSL1) laboratory.

Intranasal inoculations of naked or PLGA-PEI nanovectored DNA vaccine induce systemic and mucosal antibodies in pigs: A feasibility study

Mucosa are the routes of entry of most pathogens into animals' organisms. Reducing the important global burden of mucosal infectious diseases in livestock animals is required in the field of veterinary public health. For veterinary respiratory pathogens, one possible strategy is the development of intranasal (IN) DNA vaccination. The aim of this study was to assess the feasibility of IN DNA vaccination in pigs, an important species in livestock production industry, and a source of zoonotic diseases. To achieve this goal, we used a DNA vaccine against pseudorabies virus (PrV) encoding the immunogenic glycoprotein B (pcDNA3-gB plasmid). When pigs were inoculated with the naked DNA vaccine through the IN route, PrV-specific IgG and IgA type antibodies were detected in porcine sera. Interestingly, mucosal salivary IgA antibodies against PrV were also detected, at similar levels to those measured following intramuscular injection (positive controls). Furthermore, the IN delivery of pcDNA3-gB combined with PLGA-PEI nanoparticles resulted in similar levels of antibodies but was associated with an increase in the duration of detection of mucosal IgA for 2 out of 3 pigs. Our results suggest that there is room to improve the efficacy of IN DNA vaccination in pigs through optimization of IN inoculations, for example by using nanoparticles such as PLGA-PEI. Further studies will be dedicated to optimizing and testing the protective potential of IN DNA vaccination procedures against PrV.

Methodological recommendations on the application of Iverlong long acting preparation in the presence of parasitic diseases of livestock animals

Methodological recommendations on the application of Iverlong long acting preparation in the presence of parasitic diseases of livestock animals are given, including general data, pharmacological properties, application procedure and personal preventive measures. Iverlong is prescribed to cattle and sheep for the treatment and prophylaxis of nematodosis (dictyocaulosis, strongylatosis, strongyloidosis, neoascaridosis, bunostomosis, thelaziosis), gasterophilidae invasions (hypodermatosis, oestrosis), psoroptic scab, sarcoptic scab, sifunculatosis. Iverlong is administered to the animals as a single dose intramuscularly or subcutaneously to cattle on brachium, it is administered to sheep in the internal surface of thigh in a dose of 1 ml per 50 kg of body weight. Iverlong provides protection of animal from parasitic diseases up to 75-90 days.

In vitro activity of salinomycin and monensin derivatives against Trypanosoma brucei.

BackgroundAfrican trypanosomes are the causative agents of sleeping sickness in humans and nagana disease in livestock animals. As the few drugs available for treatment of the diseases have limited efficacy and produce adverse reactions, new and better tolerated therapies are required. Polyether ionophores have been shown to display anti-cancer, anti-microbial and anti-parasitic activity. In this study, derivatives of the polyether ionophores, salinomycin and monensin were tested for their in vitro activity against bloodstream forms of Trypanosoma brucei and human HL-60 cells.ResultsMost polyether ionophore derivatives were less trypanocidal than their corresponding parent compounds. However, two salinomycin derivatives (salinomycin n-butyl amide and salinomycin 2,2,2-trifluoroethyl ester) were identified that showed increased anti-trypanosomal activity with 50 % growth inhibition values in the mid nanomolar range and minimum inhibitory concentrations of below 1 μM similar to suramin, a drug used in the treatment of sleeping sickness. In contrast, human HL-60 cells were considerably less sensitive towards all polyether ionophore derivatives. The cytotoxic to trypanocidal activity ratio (selectivity) of the two promising compounds was greater than 250.ConclusionsThe data indicate that polyether ionophore derivatives are interesting lead compounds for rational anti-trypanosomal drug development.

Scientific literature on infectious diseases affecting livestock animals, longitudinal worldwide bibliometric analysis.

The objectives of this bibliometric analysis of the scientific literature were to describe the research subjects and the international collaborations in the field of research on infectious diseases in livestock animals including fishes and honeybees. It was based on articles published worldwide from 2006 through 2013. The source of data was the Web of Science, Core collection® and only papers fully written in English were considered. Queries were built that combined 130 descriptors related to animal species and 1213 descriptors related to diseases and pathogens. To refine and assess the accuracy of the extracted database, supplementary filters were applied to discard non-specific terms and neighbouring topics, and numerous tests were carried out on samples. For pathogens, annotation was done using a thematic terminology established to link each disease with its corresponding pathogen, which was in turn classified according to its family. A total of 62 754 articles were published in this field during this 8-year period. The average annual growth rate of the number of papers was 5%. This represents the reference data to which we compared the average annual growth rate of articles produced in each of the sub-categories that we defined. Thirty-seven percent of the papers were dedicated to ruminant diseases. Poultry, pigs and fishes were covered by respectively 21, 13 and 14% of the total. Thirty-seven percent of papers concerned bacteria, 33% viruses, 19% parasites, 2% prions, the remaining being multi-pathogens. Research on virology, especially on pigs and poultry, is increasing faster than the average. There also is increasing interest in monogastric species, fish and bees. The average annual growth rate for Asia was 10%, which is high compared to 3% for Europe and 2% for the Americas, indicating that Asia is currently playing a leading role in this field. There is a well established network of international collaborations. For 75% of the papers, the co-authors were from the same country, for 10%, they were from different countries on the same continent, and for 15%, they were from different continents. The annual growth rate of papers representing international collaborations generally is increasing more quickly than the overall average.