Modelling of paratuberculosis spread between dairy cattle farms at a regional scale
Abstract Mycobacterium avium subsp. paratuberculosis (Map) causes Johne’s disease, with large economic consequences for dairy cattle producers worldwide. Map spread between farms is mainly due to animal movements. Locally, herd size and management are expected to influence infection dynamics. To provide a better understanding of Map spread between dairy cattle farms at a regional scale, we describe the first spatio-temporal model accounting simultaneously for population and infection dynamics and indirect local transmission within dairy farms, and between-farm transmission through animal tra...
Source: Veterinary Research - September 25, 2015 Category: Veterinary Research Source Type: research

Maternal and fetal predictors of fetal viral load and death in third trimester, type 2 porcine reproductive and respiratory syndrome virus infected pregnant gilts
Abstract Minimal research has focused on understanding mechanisms underlying porcine reproductive and respiratory syndrome virus (PRRSV) induced reproductive failure. We have completed a large-scale project investigating phenotypic and genotypic predictors of reproductive PRRS severity in which numerous clinical, pathological, immunologic and viral responses were characterized in dams and fetuses. The goal was to determine which phenotypic responses were associated with fetal viral load and death after experimental infection of pregnant gilts with type 2 PRRSV, thereby elucidating mechanisms of reproductive PRRS ...
Source: Veterinary Research - September 25, 2015 Category: Veterinary Research Source Type: research

Determination of the infectious titer and virulence of an original US porcine epidemic diarrhea virus PC22A strain
Abstract The infectious dose of a virus pool of original US PEDV strain PC22A was determined in 4-day-old, cesarean-derived, colostrum-deprived (CDCD) piglets. The median pig diarrhea dose (PDD50) of the virus pool was determined as 7.35 log10 PDD50/mL, similar to the cell culture infectious titer, 7.75 log10 plaque-forming units (PFU)/mL. 100 PDD50 caused watery diarrhea in all conventional suckling piglets (n = 12) derived from a PEDV-naive sow, whereas 1000 and 10 000 PDD50 did not cause diarrhea in piglets derived from two PEDV-field exposed-recovered sows. This information is important for futu...
Source: Veterinary Research - September 25, 2015 Category: Veterinary Research Source Type: research

Identification and characterisation of microsatellite DNA markers in order to recognise the WSSV susceptible populations of marine giant black tiger shrimp, Penaeus monodon
This study will be a very effective platform towards understanding the molecular pathogenesis of WSD for generation of disease free shrimp aquaculture industry. (Source: Veterinary Research)
Source: Veterinary Research - September 25, 2015 Category: Veterinary Research Source Type: research

Lack of cross-protection against Mycoplasma haemofelis infection and signs of enhancement in “ Candidatus Mycoplasma turicensis”-recovered cats
In conclusion, the study suggests that a previous hemoplasma infection, even when the cat has ostensibly recovered, may influence subsequent infections, lead to an enhancement phenomenon and other differences in infection kinetics. (Source: Veterinary Research)
Source: Veterinary Research - September 24, 2015 Category: Veterinary Research Source Type: research

Yersinia ruckeri , the causative agent of enteric redmouth disease in fish
Abstract Enteric redmouth disease (ERM) is a serious septicemic bacterial disease of salmonid fish species. It is caused by Yersinia ruckeri, a Gram-negative rod-shaped enterobacterium. It has a wide host range, broad geographical distribution, and causes significant economic losses in the fish aquaculture industry. The disease gets its name from the subcutaneous hemorrhages, it can cause at the corners of the mouth and in gums and tongue. Other clinical signs include exophthalmia, darkening of the skin, splenomegaly and inflammation of the lower intestine with accumulation of thick yellow fluid. The bacterium en...
Source: Veterinary Research - September 24, 2015 Category: Veterinary Research Source Type: research

Cross-protection against European swine influenza viruses in the context of infection immunity against the 2009 pandemic H1N1 virus: studies in the pig model of influenza
In conclusion, infection with a live, wild type influenza virus may offer substantial cross-lineage protection against viruses of the same HA and/or NA subtype. True heterosubtypic protection, in contrast, appears to be minimal in natural influenza virus hosts. We discuss our findings in the light of the zoonotic and pandemic risks of SIVs. (Source: Veterinary Research)
Source: Veterinary Research - September 24, 2015 Category: Veterinary Research Source Type: research

Comparative analysis of rabbit hemorrhagic disease virus (RHDV) and new RHDV2 virus antigenicity, using specific virus-like particles
Abstract In 2010 a new Lagovirus related to rabbit haemorrhagic disease virus (RHDV) emerged in France and has since rapidly spread throughout domestic and wild rabbit populations of several European countries. The new virus, termed RHDV2, exhibits distinctive genetic, antigenic and pathogenic features. Notably, RHDV2 kills rabbits previously vaccinated with RHDV vaccines. Here we report for the first time the generation and characterization of RHDV2-specific virus-like particles (VLPs). Our results further confirmed the differential antigenic properties exhibited by RHDV and RHDV2, highlighting the need of using...
Source: Veterinary Research - September 24, 2015 Category: Veterinary Research Source Type: research

Previous infection with virulent strains of Newcastle disease virus reduces highly pathogenic avian influenza virus replication, disease, and mortality in chickens
In conclusion, previous infection of chickens with virulent NDV strains can reduce HPAIV replication, and consequently disease and mortality. This interference depends on the titer of the viruses used, the virulence of the NDV, and the timing of the infections. The information obtained from these studies helps to understand the possible interactions and outcomes of infection (disease and virus shedding) when HPAIV and NDV co-infect chickens in the field. (Source: Veterinary Research)
Source: Veterinary Research - September 23, 2015 Category: Veterinary Research Source Type: research

Fumonisins affect the intestinal microbial homeostasis in broiler chickens, predisposing to necrotic enteritis
This study aimed to investigate the effect of these feed contaminants on the intestinal morphology and microbiota composition, and to evaluate whether FBs predispose broilers to necrotic enteritis. One-day-old broiler chicks were divided into a group fed a control diet, and a group fed a FBs contaminated diet (18.6 mg FB1+FB2/kg feed). A significant increase in the plasma sphinganine/sphingosine ratio in the FBs-treated group (0.21 ± 0.016) compared to the control (0.14 ± 0.014) indicated disturbance of the sphingolipid biosynthesis. Furthermore, villus height and crypt depth of the ileum was significantly re...
Source: Veterinary Research - September 23, 2015 Category: Veterinary Research Source Type: research

Eimeria bovis infection modulates endothelial host cell cholesterol metabolism for successful replication
Abstract During first merogony Eimeria bovis forms large macromeronts in endothelial host cells containing>120 000 merozoites I. During multiplication, large amounts of cholesterol are indispensable for the enormous offspring membrane production. Cholesterol auxotrophy was proven for other apicomplexan parasites. Consequently they scavenge cholesterol from their host cell apparently in a parasite-specific manner. We here analyzed the influence of E. bovis infection on endothelial host cell cholesterol metabolism and found considerable differences to other coccidian parasites. Overall, free cholesterol signific...
Source: Veterinary Research - September 23, 2015 Category: Veterinary Research Source Type: research

Development of a helper cell-dependent form of peste des petits ruminants virus: a system for making biosafe antigen
Abstract Peste des petits ruminants (PPR) is a viral disease of sheep and goats that is spreading through many countries in the developing world. Work on the virus is often restricted to studies of attenuated vaccine strains or to work in laboratories that have high containment facilities. We have created a helper cell dependent form of PPR virus by removing the entire RNA polymerase gene and complementing it with polymerase made constitutively in a cell line. The resultant L-deleted virus grows efficiently in the L-expressing cell line but not in other cells. Virus made with this system is indistinguishable from...
Source: Veterinary Research - September 23, 2015 Category: Veterinary Research Source Type: research

Metatranscriptomics reveals metabolic adaptation and induction of virulence factors by Haemophilus parasuis during lung infection
Abstract Haemophilus parasuis is a common inhabitant of the upper respiratory tract of pigs, and the causative agent of Glässer’s disease. This disease is characterized by polyserositis and arthritis, produced by the severe inflammation caused by the systemic spread of the bacterium. After an initial colonization of the upper respiratory tract, H. parasuis enters the lung during the early stages of pig infection. In order to study gene expression at this location, we sequenced the ex vivo and in vivo H. parasuis Nagasaki transcriptome in the lung using a metatranscriptomic approach. Com...
Source: Veterinary Research - September 23, 2015 Category: Veterinary Research Source Type: research

A broad spectrum screening of Schmallenberg virus antibodies in wildlife animals in Germany
Abstract To identify native wildlife species possibly susceptible to infection with Schmallenberg virus (SBV), a midge-transmitted orthobunyavirus that predominantly infects domestic ruminants, samples from various free-living ruminants, but also carnivores, small mammals and wild boar were analyzed serologically. Before 2011, no SBV-specific antibodies were detectable in any of the tested species, thereafter, a large proportion of the ruminant population became seropositive, while every sample taken from carnivores or small mammals tested negative. Surprisingly, SBV-specific-antibodies were also present in a lar...
Source: Veterinary Research - September 23, 2015 Category: Veterinary Research Source Type: research

Oral administration of a select mixture of Bacillus probiotics generates Tr1 cells in weaned F4ab/acR − pigs challenged with an F4 + ETEC/VTEC/EPEC strain
Abstract Although breeding of F4 receptor − negative (F4R−) pigs may prevent post-weaning diarrhea, the underlying immunity is poorly understood. Here, various doses of a Bacillus licheniformis and Bacillus subtilis mixture (BLS-mix) were orally administered to F4ab/acR− pigs for 1 week before F4 (K88) − positive ETEC/VTEC/EPEC challenge. Administration of BLS-mix increased the percentage of Foxp3−IL-10+ T cells but not of Foxp3+IL-10+ regulatory T (Treg) cells among peripheral blood CD4+ T cells. A low dose of BLS-mix feeding resulted in increased th...
Source: Veterinary Research - September 17, 2015 Category: Veterinary Research Source Type: research

phoP , SPI1, SPI2 and aroA mutants of Salmonella Enteritidis induce a different immune response in chickens
In conclusion, SPI1 and phoP mutants induced protective immunity without inducing an inflammatory response and antibody production. Inoculation of chickens with the SPI2 and aroA mutants also led to protective immunity but was associated with inflammation and antibody production. The differences in interaction between the mutants and chicken host can be used for a more detailed understanding of the chicken immune system. (Source: Veterinary Research)
Source: Veterinary Research - September 17, 2015 Category: Veterinary Research Source Type: research

Piscine orthoreovirus (PRV) in red and melanised foci in white muscle of Atlantic salmon ( Salmo salar )
Abstract Melanised focal changes (black spots) are common findings in the white skeletal muscle of seawater-farmed Atlantic salmon (Salmo salar). Fillets with melanised focal changes are considered as lower quality and cause large economic losses. It has been suggested that red focal changes (red spots) precede the melanised focal changes. In the present work, we examined different populations of captive and wild salmon for the occurrence of both types of changes, which were investigated for the presence of different viruses by immunohistochemistry and RT-qPCR. The occurrence of red or melanised foci varied signi...
Source: Veterinary Research - September 8, 2015 Category: Veterinary Research Source Type: research

Bagaza virus is pathogenic and transmitted by direct contact in experimentally infected partridges, but is not infectious in house sparrows and adult mice
This study confirms that the red-legged partridge is a susceptible host for BAGV infection, and that this pathogen is transmitted by direct contact. Long-lasting viral loads detected in calami of immature feathers demonstrate that feather sampling could be a useful strategy in active surveillance programs for early detection of BAGV. (Source: Veterinary Research)
Source: Veterinary Research - September 4, 2015 Category: Veterinary Research Source Type: research

Ecological approaches in veterinary epidemiology: mapping the risk of bat-borne rabies using vegetation indices and night-time light satellite imagery
In conclusion, ecological niche modeling applications for mapping disease risk at coarse geographic scales have a promising future, especially with refinement and enrichment of models with additional information, such as night-time light data, which increased substantially the model’s ability to anticipate human rabies. (Source: Veterinary Research)
Source: Veterinary Research - September 4, 2015 Category: Veterinary Research Source Type: research

Comparison of the pathogenesis of the highly passaged MCMV Smith strain with that of the low passaged MCMV HaNa1 isolate in BALB/c mice upon oronasal inoculation
Abstract Murine cytomegalovirus (MCMV) Smith strain is widely used in mouse models to study HCMV infections. Due to high serial passages, MCMV Smith has acquired genetic and biological changes. Therefore, a low passaged strain would be more relevant to develop mouse models. Here, the pathogenesis of an infection with MCMV Smith was compared with that of an infection with a low passaged Belgian MCMV isolate HaNa1 in BALB/c adult mice following oronasal inoculation with either a low (104 TCID50/mouse) or high (106 TCID50/mouse) inoculation dose. Both strains were mainly replicating in nasal mucosa and submandibular...
Source: Veterinary Research - September 4, 2015 Category: Veterinary Research Source Type: research

Protective role of murine norovirus against Pseudomonas aeruginosa acute pneumonia
Abstract The murine norovirus (MNV) is a recently discovered mouse pathogen, representing the most common contaminant in laboratory mouse colonies. Nevertheless, the effects of MNV infection on biomedical research are still unclear. We tested the hypothesis that MNV infection could alter immune response in mice with acute lung infection. Here we report that co-infection with MNV increases survival of mice with Pseudomonas aeruginosa acute lung injury and decreases in vivo production of pro-inflammatory cytokines. Our results suggest that MNV infection can deeply modify the parameters studied in conventional model...
Source: Veterinary Research - September 4, 2015 Category: Veterinary Research Source Type: research

Should they stay, or should they go? Relative future risk of bovine tuberculosis for interferon-gamma test-positive cattle left on farms
Abstract Bovine tuberculosis (bTB), caused by Mycobacterium bovis, is a serious infectious disease that remains an ongoing concern for cattle farming worldwide. Tuberculin skin-tests are often used to identify infected animals (reactors) during test-and-cull programs, however, due to relatively poor sensitivity, additional tests can be implemented in parallel. For example, in Northern Ireland interferon-gamma (IFN-g) testing is used in high-risk herds. However, skin-test negative animals which are positive to the IFN-g test are not required by law to be slaughtered – therefore the final choice for these ani...
Source: Veterinary Research - September 4, 2015 Category: Veterinary Research Source Type: research

Veterinary Research reviewer acknowledgement 2014
Contributing reviewers The Veterinary Research editorial team would sincerely like to thank all of our reviewers who contributed to peer review for the journal in 2014. (Source: Veterinary Research)
Source: Veterinary Research - August 26, 2015 Category: Veterinary Research Source Type: research

DNA vaccines encoding the envelope protein of West Nile virus lineages 1 or 2 administered intramuscularly, via electroporation and with recombinant virus protein induce partial protection in large falcons ( Falco spp.)
In conclusion, the vaccines can be used safely in falcons to reduce mortality and clinical signs and to lower the risk of virus transmission due to decreased levels of virus shedding and viremia, but full protection was not achieved in all groups. (Source: Veterinary Research)
Source: Veterinary Research - August 17, 2015 Category: Veterinary Research Source Type: research

A novel epidemiological model to better understand and predict the observed seasonal spread of Pestivirus in Pyrenean chamois populations
In this study, we sought to better understand how the seasonality of both the demography and social contacts of a mountain ungulate population impacts the spread of a pestivirus within, and the dynamics of, this population. We propose a mathematical model to represent this complex biological system. The pestivirus can be transmitted both horizontally through direct contact and vertically in utero. Vertical transmission leads to abortion or to the birth of persistently infected animals with a short life expectancy. Horizontal transmission involves a complex dynamics because of seasonal variations in contact among sexes and ...
Source: Veterinary Research - July 24, 2015 Category: Veterinary Research Source Type: research

What variables are important in predicting bovine viral diarrhea virus? A random forest approach
In this study we trained a random forest (RF) prediction model and performed variable importance analysis to identify factors associated with BVDV occurrence. In addition, we assessed the influence of features selection on RF performance and evaluated its predictive power relative to other popular classifiers and to logistic regression. We found that RF classification model resulted in an average error rate of 32.03% for the negative class (negative for BVDV) and 36.78% for the positive class (positive for BVDV).The RF model presented area under the ROC curve equal to 0.702. Variable importance analysis revealed that impor...
Source: Veterinary Research - July 24, 2015 Category: Veterinary Research Source Type: research

A combinational approach of multilocus sequence typing and other molecular typing methods in unravelling the epidemiology of Erysipelothrix rhusiopathiae strains from poultry and mammals
Abstract Erysipelothrix rhusiopathiae infections re-emerged as a matter of great concern particularly in the poultry industry. In contrast to porcine isolates, molecular epidemiological traits of avian E. rhusiopathiae isolates are less well known. Thus, we aimed to (i) develop a multilocus sequence typing (MLST) scheme for E. rhusiopathiae, (ii) study the congruence of strain grouping based on pulsed-field gel electrophoresis (PFGE) and MLST, (iii) determine the diversity of the dominant immunogenic protein SpaA, and (iv) examine the distribution of genes putatively linked with virulence among fi...
Source: Veterinary Research - July 21, 2015 Category: Veterinary Research Source Type: research

Bridge hosts, a missing link for disease ecology in multi-host systems
Abstract In ecology, the grouping of species into functional groups has played a valuable role in simplifying ecological complexity. In epidemiology, further clarifications of epidemiological functions are needed: while host roles may be defined, they are often used loosely, partly because of a lack of clarity on the relationships between a host’s function and its epidemiological role. Here we focus on the definition of bridge hosts and their epidemiological consequences. Bridge hosts provide a link through which pathogens can be transmitted from maintenance host populations or communities to receptive popu...
Source: Veterinary Research - July 21, 2015 Category: Veterinary Research Source Type: research

Potassium permanganate elicits a shift of the external fish microbiome and increases host susceptibility to columnaris disease
This study evaluated the effect of PP on the external microbiome of channel catfish and investigated if dysbiosis leads to an increase in disease susceptibility. Columnaris disease, caused by Flavobacterium columnare, was used as disease model. Four treatments were compared in the study: (I) negative control (not treated with PP nor challenged with F. columnare), (II) treated but not challenged, (III) not treated but challenged, and (IV) treated and challenged. Ribosomal intergenic spacer analysis (RISA) and pyrosequencing were used to analyze changes in the external microbiome during the experiment. Exposure to PP signifi...
Source: Veterinary Research - July 15, 2015 Category: Veterinary Research Source Type: research

Acquired transmissibility of sheep-passaged L-type bovine spongiform encephalopathy prion to wild-type mice
In this study, we examined the transmissibility of sheep-passaged L-BSE prions to wild-type mice. Disease-associated prion protein (PrPSc) was detected in the brain and/or lymphoid tissues during the lifespan of mice that were asymptomatic subclinical carriers, indicating that wild-type mice were susceptible to sheep-passaged L-BSE. The morphological characteristics of the PrPSc of sheep-passaged L-BSE included florid plaques that were distributed mainly in the cerebral cortex and hippocampus of subsequent passaged mice. The PrPSc glycoform profiles of wild-type mice infected with sheep-passaged L-BSE were similar to those...
Source: Veterinary Research - July 13, 2015 Category: Veterinary Research Source Type: research

Extracellular cyclophilin A possesses chemotaxic activity in cattle
Abstract Cyclophilin A (CyPA) was originally discovered in bovine thymocytes as a cytosolic binding protein of the immunosuppressive drug cyclosporine A. Recent studies have revealed that in mice and humans, CyPA is secreted from cells in injured or infected tissues and plays a role in recruiting inflammatory cells in those tissues. Here we found that in cattle abundant level of extracellular CyPA was observed in tissues with inflammation. To aid in investigating the role of extracellular CyPA in cattle, we generated recombinant bovine CyPA (rbCyPA) and tested its biological activity as an inflammatory mediator. ...
Source: Veterinary Research - July 11, 2015 Category: Veterinary Research Source Type: research

Proteomic analysis of purified turkey adenovirus 3 virions
Abstract Turkey adenovirus 3 (TAdV-3) causes high mortality and significant economic losses to the turkey industry. However, little is known about the molecular determinants required for viral replication and pathogenesis. Moreover, TAdV-3 does not grow well in cell culture, thus detailed structural studies of the infectious particle is particularly challenging. To develop a better understanding of virus-host interactions, we performed a comprehensive proteomic analysis of proteinase K treated purified TAdV-3 virions isolated from spleens of infected turkeys, by utilizing one-dimensional liquid chromatography mas...
Source: Veterinary Research - July 9, 2015 Category: Veterinary Research Source Type: research

Efficacy of a live attenuated vaccine in classical swine fever virus postnatally persistently infected pigs
Abstract Classical swine fever (CSF) causes major losses in pig farming, with various degrees of disease severity. Efficient live attenuated vaccines against classical swine fever virus (CSFV) are used routinely in endemic countries. However, despite intensive vaccination programs in these areas for more than 20 years, CSF has not been eradicated. Molecular epidemiology studies in these regions suggests that the virus circulating in the field has evolved under the positive selection pressure exerted by the immune response to the vaccine, leading to new attenuated viral variants. Recent work by our group demo...
Source: Veterinary Research - July 9, 2015 Category: Veterinary Research Source Type: research

Recent advances in Brucella abortus vaccines
Abstract Brucella abortus vaccines play a central role in bovine brucellosis control/eradication programs and have been successfully used worldwide for decades. Strain 19 and RB51 are the approved B. abortus vaccines strains most commonly used to protect cattle against infection and abortion. However, due to some drawbacks shown by these vaccines much effort has been undertaken for the development of new vaccines, safer and more effective, that could also be used in other susceptible species of animals. In this paper, we present a review of the main aspects of the vaccines that have been used in t...
Source: Veterinary Research - July 8, 2015 Category: Veterinary Research Source Type: research

Serological profile of foot-and-mouth disease in wildlife populations of West and Central Africa with special reference to Syncerus caffer subspecies
This study reports the FMD serological profile extracted from samples (n = 696) collected from wildlife of West and Central Africa between 1999 and 2003. An overall prevalence of FMDV NSP reactive sera of 31.0% (216/696) was estimated, where a significant difference in seropositivity (p = 0.000) was reported for buffalo (64.8%) as opposed to other wild animal species tested (17.8%). Different levels of exposure to the FMDV resulted for each of the buffalo subspecies sampled (p = 0.031): 68.4%, 50.0% and 0% for Nile Buffalo, West African Buffalo and African Forest Buffalo, respectively. The chara...
Source: Veterinary Research - July 8, 2015 Category: Veterinary Research Source Type: research

Differential replication properties among H9N2 avian influenza viruses of Eurasian origin
Abstract Avian influenza H9N2 viruses have become panzootic in Eurasia causing respiratory manifestations, great economic losses and occasionally being transmitted to humans. To evaluate the replication properties and compare the different virus quantification methods, four Eurasian H9N2 viruses from different geographical origins were propagated in embryonated chicken egg (ECE) and Madin-Darby canine kidney epithelial cell systems. The ECE-grown and cell culture-grown viruses were monitored for replication kinetics based on tissue culture infectious dose (TCID50), Hemagglutination (HA) test and quantitative real...
Source: Veterinary Research - July 6, 2015 Category: Veterinary Research Source Type: research

A large-scale genomic approach affords unprecedented resolution for the molecular epidemiology and evolutionary history of contagious caprine pleuropneumonia
This study shows how combining large-scale genomic data with spatial and temporal data makes it possible to obtain a comprehensive view of the epidemiology of CCPP, a precondition for the development of improved disease surveillance and control measures. (Source: Veterinary Research)
Source: Veterinary Research - July 6, 2015 Category: Veterinary Research Source Type: research

Pulsed-field gel electrophoresis and multi locus sequence typing for characterizing genotype variability of Yersinia ruckeri isolated from farmed fish in France
In this study, the pulsed-field gel electrophoresis (PFGE) and multi locus sequence typing (MLST) methods were used to describe a population of isolates from outbreaks on French fish farms. For the PFGE analysis, two enzymes (NotI and AscI) were used separately and together. Results from combining the enzymes showed the great homogeneity of the outbreak population with a similarity > 80.0% but a high variability within the cluster (cut-off value = 80.0%) with a total of 43 pulsotypes described and an index of diversity = 0.93. The dominant pulsotypes described with NotI (PtN4 an...
Source: Veterinary Research - June 23, 2015 Category: Veterinary Research Source Type: research

Maternal immunity enhances systemic recall immune responses upon oral immunization of piglets with F4 fimbriae
Abstract F4 enterotoxigenic Escherichia coli (ETEC) cause diarrhoea and mortality in piglets leading to severe economic losses. Oral immunization of piglets with F4 fimbriae induces a protective intestinal immune response evidenced by an F4-specific serum and intestinal IgA response. However, successful oral immunization of pigs with F4 fimbriae in the presence of maternal immunity has not been demonstrated yet. In the present study we aimed to evaluate the effect of maternal immunity on the induction of a systemic immune response upon oral immunization of piglets. Whereas F4-specific IgG and IgA could be induced...
Source: Veterinary Research - June 23, 2015 Category: Veterinary Research Source Type: research

The within host dynamics of Mycobacterium avium ssp . paratuberculosis infection in cattle: where time and place matter
Abstract Johne’s disease or paratuberculosis, caused by Mycobacterium avium subsp. paratuberculosis (MAP), occurs in domestic and wild animals worldwide, causing a significant economic loss to livestock industries. After a prolonged incubation time, infected cattle shed MAP bacilli into feces and spread the disease to an uninfected animal population. It is largely unknown how (or whether) the interplay between the pathogen and the host immunity determines timing of shedding after the long incubation time. Such information would provide an understanding of pathogenesis in individual animals and the epidemiol...
Source: Veterinary Research - June 19, 2015 Category: Veterinary Research Source Type: research

Longitudinal data collection of Mycobacterium avium subspecies Paratuberculosis infections in dairy herds: the value of precise field data
Abstract Longitudinal infection data on Mycobacterium avium subspecies paratuberculosis (MAP) was collected on three dairy farms in Northeastern United States during approximately 10 years. Precise data on animal characteristics and animal location within farm were collected on these farms. Cows were followed over time with regard to MAP status during biannual fecal and serum sampling and quarterly serum sampling. Approximately 13 000 serum samples, 6500 fecal samples and 2000 tissue samples were collected during these years. Prevalence of positive samples was 1.4% for serological samples, 2.2% in fecal samp...
Source: Veterinary Research - June 19, 2015 Category: Veterinary Research Source Type: research

The long subclinical phase of Mycobacterium avium ssp. paratuberculosis infections explained without adaptive immunity
In conclusion, our models show that the long subclinical period of MAP infection can result from the structural organization of the infection in granulomatous lesions with an important role for innate rather than adaptive immunity. It thus provides a reasonable hypothesis that needs further investigation. (Source: Veterinary Research)
Source: Veterinary Research - June 19, 2015 Category: Veterinary Research Source Type: research

Evaluating contribution of the cellular and humoral immune responses to the control of shedding of Mycobacterium avium spp. paratuberculosis in cattle
In this study, 20 MAP-infected calves were followed for nearly 5 years during which MAP shedding, antigen-specific cellular (LPT) and humoral (ELISA) immune responses were measured. We found that MAP-specific cellular immune response developed slowly, with the peak of the immune response occurring one year post infection. MAP-specific humoral immunity expanded only in a subset of animals. Only in a subset of animals there was a statistically significant negative correlation between the amount of MAP shedding and magnitude of the MAP-specific cellular immune response. Direct fitting of simple mechanistic mathematical m...
Source: Veterinary Research - June 19, 2015 Category: Veterinary Research Source Type: research

An immuno-epidemiological model for Johne’s disease in cattle
Abstract To better understand the mechanisms involved in the dynamics of Johne’s disease in dairy cattle, this paper illustrates a novel way to link a within-host model for Mycobacterium avium ssp. paratuberculosis with an epidemiological model. The underlying variable in the within-host model is the time since infection. Two compartments, infected macrophages and T cells, of the within-host model feed into the epidemiological model through the direct transmission rate, disease-induced mortality rate, the vertical transmission rate, and the shedding of MAP into the environment. The epidemiological reproduct...
Source: Veterinary Research - June 19, 2015 Category: Veterinary Research Source Type: research

Differences in intermittent and continuous fecal shedding patterns between natural and experimental Mycobacterium avium subspecies paratuberculosis infections in cattle
The objective of this paper is to study shedding patterns of cows infected with Mycobacterium avium subsp. paratuberculosis (MAP). While multiple single farm studies of MAP dynamics were reported, there is not large scale meta-analysis of both natural and experimental infections. Large difference in shedding patterns between experimentally and naturally infected cows were observed. Experimental infections are thus probably driven by different pathological mechanisms. For further evaluations of shedding patterns only natural infections were used. Within such infections, the transition to high shedding was studied as a proxy...
Source: Veterinary Research - June 19, 2015 Category: Veterinary Research Source Type: research

Two state model for a constant disease hazard in paratuberculosis (and other bovine diseases)
Abstract Many diseases are characterized by a long and varying sub-clinical period. Two main mechanisms can explain such periods: a slow progress toward disease or a sudden transition from a healthy state to a disease state induced by internal or external events. We here survey epidemiological features of the amount of bacteria shed during Mycobacterium Avium Paratuberculosis (MAP) infection to test which of these two models, slow progression or sudden transition (or a combination of the two), better explains the transition from intermittent and low shedding to high shedding. Often, but not always, high shedding ...
Source: Veterinary Research - June 19, 2015 Category: Veterinary Research Source Type: research

Genetic diversity of Mycobacterium avium subspecies paratuberculosis and the influence of strain type on infection and pathogenesis: a review
Abstract Mycobacterium avium subspecies paratuberculosis (Map) is an important pathogen that causes a chronic, progressive granulomatous enteritis known as Johne’s disease or paratuberculosis. The disease is endemic in many parts of the world and responsible for considerable losses to the livestock and associated industries. Diagnosis and control are problematic, due mostly to the long incubation period of the disease when infected animals show no clinical signs and are difficult to detect, and the ability of the organism to survive and persist in the environment. The existence of phenotypically...
Source: Veterinary Research - June 19, 2015 Category: Veterinary Research Source Type: research

Calves shedding Mycobacterium avium subspecies paratuberculosis are common on infected dairy farms
The objectives were 1) to estimate the prevalence of MAP-shedding young stock in MAP-infected dairy herds, and identify predictors for test-positive young stock; and 2) to estimate proportions of MAP-contaminated young stock group housing pens and air spaces, and furthermore, identify predictors for test-positive pens. Fecal samples were collected from 2606 young stock on 18 MAP-infected dairy farms. Environmental fecal samples were collected from all group-housing pens and dust samples were collected from all barns. All individual samples were analysed using IS900 and F57 qPCR; fecal samples positive by either PCR and all...
Source: Veterinary Research - June 19, 2015 Category: Veterinary Research Source Type: research

Within- and between-host mathematical modeling of Mycobacterium avium subspecies paratuberculosis (MAP) infections as a tool to study the dynamics of host-pathogen interactions in bovine paratuberculosis
(Source: Veterinary Research)
Source: Veterinary Research - June 19, 2015 Category: Veterinary Research Source Type: research

Dam Mycobacterium avium subspecies paratuberculosis (MAP) infection status does not predetermine calves for future shedding when raised in a contaminated environment: a cohort study
The objective of this study was to quantify the association between the MAP status of dams as determined by the presence of MAP DNA and antibody in colostrum and that of DNA in faeces and the environment with subsequent MAP shedding of their daughters. A cohort of 117 dam-daughter pairs giving birth/being born on eight commercial dairy farms with endemic paratuberculosis was followed where colostrum, faecal and environmental samples (dust) were analysed for the presence of MAP using an IS900 real-time PCR. Antibodies in colostrum were measured by ELISA. Analysis of dust samples showed that on all farms environmental MAP ex...
Source: Veterinary Research - June 19, 2015 Category: Veterinary Research Source Type: research