Publications by authors named "Frédéric Farnir"

67 Publications

Optimisation of a PMAxx™-RT-qPCR Assay and the Preceding Extraction Method to Selectively Detect Infectious Murine Norovirus Particles in Mussels.

Food Environ Virol 2021 Mar 3;13(1):93-106. Epub 2021 Jan 3.

Veterinary Virology and Animal Viral Diseases, Department of Infectious and Parasitic Diseases, FARAH Research Centre, Faculty of Veterinary Medicine, Liège University, B43b, Quartier Vallée 2, Avenue de Cureghem, 10, 4000, Liège, Belgium.

Human noroviruses are a major cause for gastroenteritis outbreaks. Filter-feeding bivalve molluscs, which accumulate noroviruses in their digestive tissues, are a typical vector for human infection. RT-qPCR, the established method for human norovirus detection in food, does not allow discrimination between infectious and non-infectious viruses and can overestimate potentially infectious viral loads. To develop a more accurate method of infectious norovirus load estimation, we combined intercalating agent propidium monoazide (PMAxx™)-pre-treatment with RT-qPCR assay using in vitro-cultivable murine norovirus. Three primer sets targeting different genome regions and diverse amplicon sizes were used to compare one-step amplification of a short genome fragment to three two-step long-range RT-qPCRs (7 kbp, 3.6 kbp and 2.3 kbp amplicons). Following initial assays performed on untreated infectious, heat-, or ultraviolet-inactivated murine noroviruses in PBS suspension, PMAxx™ RT-qPCRs were implemented to detect murine noroviruses subsequent to their extraction from mussel digestive tissues; virus extraction via anionic polymer-coated magnetic beads was compared with the proteinase K-dependent ISO norm. The long-range RT-qPCR process detecting fragments of more than 2.3 kbp allowed accurate estimation of the infectivity of UV-damaged murine noroviruses. While proteinase K extraction limited later estimation of PMAxx™ pre-treatment effects and was found to be unsuited to the assay, magnetic bead-captured murine noroviruses retained their infectivity. Genome copies of heat-inactivated murine noroviruses differed by 2.3 log between RT-qPCR and PMAxx™-RT-qPCR analysis in bivalve molluscs, the PMAxx™ pre-treatment allowing a closer approximation of infectious titres. The combination of bead-based virus extraction and PMAxx™ RT-qPCR thus provides a more accurate model for the estimation of noroviral bivalve mollusc contamination than the conjunction of proteinase K extraction and RT-qPCR and has the potential (once validated utilising infectious human norovirus) to provide an added measure of security to food safety authorities in the hazard assessment of potential bivalve mollusc contamination.
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http://dx.doi.org/10.1007/s12560-020-09454-wDOI Listing
March 2021

Modeling the Growth and Interaction Between , spp., and in Minced Pork Samples.

Front Microbiol 2020 9;11:639. Epub 2020 Apr 9.

Department of Food Sciences, Fundamental and Applied Research for Animal and Health, Faculty of Veterinary Medicine, University of Liège, Liège, Belgium.

The aim of this study was to obtain the growth parameters of specific spoilage micro-organisms previously isolated in minced pork (MP) samples and to develop a three-spoilage species interaction model under different storage conditions. Naturally contaminated samples were used to validate this approach by considering the effect of the food microbiota. Three groups of bacteria were inoculated on irradiated samples, in mono- and in co-culture experiments ( = 1152): , , and spp. ( and ). Samples were stored in two food packaging [food wrap and modified atmosphere packaging (CO 30%/O 70%)] at three isothermal conditions (4, 8, and 12°C). Analysis was carried out by using both 16S rRNA gene amplicon sequencing and classical microbiology in order to estimate bacterial counts during the storage period. Growth parameters were obtained by fitting primary (Baranyi) and secondary (square root) models. The food packaging shows the highest impact on bacterial growth rates, which in turn have the strongest influence on the shelf life of food products. Based on these results, a three-spoilage species interaction model was developed by using the modified Jameson-effect model and the Lotka Volterra (prey-predator) model. The modified Jameson-effect model showed slightly better performances, with 40-86% out of the observed counts falling into the Acceptable Simulation Zone (ASZ). It only concerns 14-48% for the prey-predator approach. These results can be explained by the fact that the dynamics of experimental and validation datasets seems to follow a Jameson behavior. On the other hand, the Lotka Volterra model is based on complex interaction factors, which are included in highly variable intervals. More datasets are probably needed to obtained reliable factors, and so better model fittings, especially for three- or more-spoilage species interaction models. Further studies are also needed to better understand the interaction of spoilage bacteria between them and in the presence of natural microbiota.
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http://dx.doi.org/10.3389/fmicb.2020.00639DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7160237PMC
April 2020

Productive performance and egg and meat quality of two indigenous poultry breeds in Vietnam, Ho and Dong Tao, fed on commercial feed.

Animals (Basel) 2020 Mar 1;10(3). Epub 2020 Mar 1.

Fundamental and Applied Research in Animal and Health (FARAH) Department of Veterinary Management of Animal Resources, Faculty of Veterinary Medicine, University of Liege, Liege 4000, Belgium.

The objective of this work was the evaluation of the meat production and laying performances, and the meat and egg quality of two breeds of Vietnamese broiler chickens, Ho and Dong Tao, fed on a commercial diet. In a survey, we continuously recorded for 28 weeks, the data on the production performance and meat quality of 250 chicks from each breed. We investigated egg laying and egg quality using 36 Ho and 32 Dong Tao hens during 52 weeks of laying. The growth patterns were similar for the two breeds. Feed conversion ratios were also similar, and demonstrated the low efficiency of these two breeds when compared to commercial broilers. Slaughter age proved to affect several carcass yield characteristics, showing that slaughtering between 16 and 20 weeks might be better than at the usual age of 28 weeks. Yield, carcass composition and meat quality differed between the two studied breeds. The eggs production and number of embryonated eggs were low for the two breeds when compared to other breeds, with a lower hatching performance in Ho than in Dong Tao. In summary, the production performances of Ho and Dong Tao chickens were low, even when birds were fed a commercial diet. The study demonstrates the need to find ways to improve the production and reproduction performances of these animals, in order to contribute to the program of conservation and exploitation of these two breeds.
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http://dx.doi.org/10.3390/ani10030408DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7143232PMC
March 2020

Two-dimensional speckle tracking echocardiography in goats: repeatability, variability, and validation of the technique using an exercise test and an experimentally induced acute ischemic cardiomyopathy.

BMC Vet Res 2020 Feb 14;16(1):56. Epub 2020 Feb 14.

Equine Clinic, Department of Companion Animals and Equids, Faculty of Veterinary Medicine, University of Liege, Boulevard de Colonster 20, Bât B41, Liege, Sart Tilman, Belgium.

Background: Two-dimensional speckle tracking (2DST) technique has been validated in numerous animal species, but neither studies of repeatability nor measurements after exercise or in animals with cardiac disease have been reported in goats. Goats are an attractive candidate for animal models in human cardiology because they are easy to handle and have a body and heart size comparable to that of humans. Therefore, the aim of this study was to validate this technique in goats for further clinical and experimental applications in this species.

Results: This study was divided into several steps. First, a standardized echocardiographic protocol was performed and 5 cineloops of a right parasternal short-axis view at papillary muscles level were recorded three times at one-day intervals in ten healthy adult unsedated Saanen goats to test repeatability and variability of 2DST measurements. Then, the same measurements were performed immediately before and after a standardized exercise on treadmill in seven of the goats, and at 24 h after induction of an experimental ischemic cardiomyopathy in five of the goats, to test the reliability of the technique to assess physiological and pathological changes. Average and regional measurements of radial and circumferential strain and strain rate, radial displacement, rotation and rotation rate were obtained. Comparisons were performed using two-way ANOVA (p < 0.05). Caprine 2DST average measurements have demonstrated a good repeatability with a low to moderate variability for all measurements except for the diastolic peaks of the circumferential strain rate, radial strain rate and rotation rate. Segmental 2DST measurements were less repeatable than average measurements. Time effect of two-way ANOVA was significant for anteroseptal segment diastolic peaks measurements, rotation and rotation rate measurements. Overall variability of segmental measurements was moderate or high. Segmental and average peak values obtained after exercise and after myocardial ischemia were significantly different than curves obtained at baseline.

Conclusions: The results of this study are consistent with those previously described in other animal species and humans. 2DST echocardiography is a valid technique to evaluate physiological and pathological changes in myocardial function in goats, despite the technical limitations observed in this species.
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http://dx.doi.org/10.1186/s12917-020-02277-8DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7023799PMC
February 2020

Assessment of Spoilage Bacterial Communities in Food Wrap and Modified Atmospheres-Packed Minced Pork Meat Samples by 16S rDNA Metagenetic Analysis.

Front Microbiol 2019 21;10:3074. Epub 2020 Jan 21.

Department of Food Sciences, Fundamental and Applied Research for Animals & Health (FARAH), Faculty of Veterinary Medicine, University of Liège, Liège, Belgium.

Although several studies have focused on the dynamics of bacterial food community, little is known about the variability of batch production and microbial changes that occur during storage. The aim of the study was to characterize the microbial spoilage community of minced pork meat samples, among different food production and storage, using both 16S rRNA gene sequencing and classical microbiology. Three batches of samples were obtained from four local Belgian facilities (A-D) and stored until shelf life under food wrap (FW) and modified atmosphere packaging (MAP, CO 30%/O 70%), at constant and dynamic temperature. Analysis of 288 samples were performed by 16S rRNA gene sequencing in combination with counts of psychrotrophic and lactic acid bacteria at 22°C. At the first day of storage, different psychrotrophic counts were observed between the four food companies (Kruskal-Wallist test, -value < 0.05). Results shown that lowest microbial counts were observed at the first day for industries D and A (4.2 ± 0.4 and 5.6 ± 0.1 log CFU/g, respectively), whereas industries B and C showed the highest results (7.5 ± 0.4 and 7.2 ± 0.4 log CFU/g). At the end of the shelf life, psychrotrophic counts for all food companies was over 7.0 log CFU/g. With metagenetics, 48 OTUs were assigned. At the first day, the genus (86.7 and 19.9% for food industries A and C, respectively) and (38.7 and 25.7% for food companies B and D, respectively) were dominant. During the storage, a total of 12 dominant genera (>5% in relative abundance) were identified in MAP and 7 in FW. was more present in FW and this genus was potentially replaced by in MAP (two-sided Welch's -test, -value < 0.05). Also, a high Bray-Curtis dissimilarity in genus relative abundance was observed between food companies and batches. Although the bacteria consistently dominated the microbiota in our samples are known, results indicated that bacterial diversity needs to be addressed on the level of food companies, batches variation and food storage conditions. Present data illustrate that the combined approach provides complementary results on microbial dynamics in minced pork meat samples, considering batches and packaging variations.
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http://dx.doi.org/10.3389/fmicb.2019.03074DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6985204PMC
January 2020

Effect of an antimicrobial drug on lung microbiota in healthy dogs.

Heliyon 2019 Nov 14;5(11):e02802. Epub 2019 Nov 14.

Department of Clinical Sciences, FARAH, Faculty of Veterinary Medicine, University of Liège, 4000, Liège, Belgium.

Alterations of the lung microbiota (LM) are associated with clinical features in chronic lung diseases (CLDs) with growing evidence that an altered LM contributes to the pathogenesis of such disorders. The common use of antimicrobial drugs in the management of CLDs likely represents a confounding factor in the study of the LM. The aim of the present study was to assess the effect of oral administration of amoxicillin/clavulanic acid (AC) on the LM in healthy dogs ( = 6) at short (immediately after stopping AC [D10]) and medium-term (16 days after stopping AC [D26]). Metagenetic analyses were performed on the V1-V3 hypervariable region of 16S rDNA after extraction of total bacterial DNA from samples of bronchoalveolar lavage fluid (BALF). AC did not induce significant changes in BALF cellular counts or in the bacterial load or microbial richness, evenness and α-diversity, while the β-diversity was clearly modified at D10 compared with D0 (before AC administration) and D26 ( < 0.01). The relative abundance of Bacteroidetes and Proteobacteria increased at D10 ( < 0.01) in comparison with D0 and D26 ( < 0.01). The relative abundance of Firmicutes decreased from D0 to D10 ( < 0.01) and increased from D10 to D26 ( < 0.01), but was still lower than at D0 ( < 0.01). The proportion of Actinobacteria increased at D26 compared with D0 and D10 ( < 0.01). Significant differences between timepoints at the level of family, genus or species were not found. In conclusion, in healthy dogs, oral administration of AC induces significant changes in LM at the phyla level and in the β-diversity. Most changes normalize within 2 weeks after discontinuation of AC.
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http://dx.doi.org/10.1016/j.heliyon.2019.e02802DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6895694PMC
November 2019

Non-classical tissue monocytes and two functionally distinct populations of interstitial macrophages populate the mouse lung.

Nat Commun 2019 09 3;10(1):3964. Epub 2019 Sep 3.

Laboratory of Immunophysiology, GIGA Institute, Liège University, Avenue de l'Hôpital 11, B34, 4000, Liège, Belgium.

Resident tissue macrophages (RTM) can fulfill various tasks during development, homeostasis, inflammation and repair. In the lung, non-alveolar RTM, called interstitial macrophages (IM), importantly contribute to tissue homeostasis but remain little characterized. Here we show, using single-cell RNA-sequencing (scRNA-seq), two phenotypically distinct subpopulations of long-lived monocyte-derived IM, i.e. CD206 and CD206IM, as well as a discrete population of extravasating CD64CD16.2 monocytes. CD206 IM are peribronchial self-maintaining RTM that constitutively produce high levels of chemokines and immunosuppressive cytokines. Conversely, CD206IM preferentially populate the alveolar interstitium and exhibit features of antigen-presenting cells. In addition, our data support that CD64CD16.2 monocytes arise from intravascular Ly-6C patrolling monocytes that enter the tissue at steady-state to become putative precursors of CD206IM. This study expands our knowledge about the complexity of lung IM and reveals an ontogenic pathway for one IM subset, an important step for elaborating future macrophage-targeted therapies.
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http://dx.doi.org/10.1038/s41467-019-11843-0DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6722135PMC
September 2019

Interbreed variation of biomarkers of lipid and glucose metabolism in dogs.

Vet Clin Pathol 2018 Dec 17;47(4):582-588. Epub 2018 Dec 17.

University of Liège, Liège, Belgium.

Background: Markers of lipid and glucose metabolism are used in both clinical practice and research. Detection of abnormal laboratory results often relies on species-specific reference intervals, but interbreed variation can also affect data interpretation.

Objectives: The purpose of the present study was to compare concentrations of selected biochemical variables among different dog breeds.

Methods: We analyzed a database containing information on biochemical variables from 534 dogs belonging to nine different breeds. All dogs were confirmed to be healthy based on history, physical examination, and ancillary tests. Concentrations of glucose, fructosamine, insulin, cholesterol, triglycerides, fatty acids, and C-reactive protein were compared using the nonparametric Kruskal-Wallis and Dunn's tests.

Results: All variables tested showed significant interbreed differences, although all breeds remained within the previously established RIs for dogs. Fructosamine, insulin, and cholesterol showed a wide interbreed variation that could affect the interpretation of results.

Conclusions: Breed is an important factor to consider when assessing energy metabolism in dogs, especially for markers like fructosamine, insulin, and cholesterol, which vary considerably among breeds.
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http://dx.doi.org/10.1111/vcp.12673DOI Listing
December 2018

Aggregation of experts: an application in the field of "interactomics" (detection of interactions on the basis of genomic data).

BMC Bioinformatics 2018 Nov 21;19(1):445. Epub 2018 Nov 21.

Department of Biostatistics, Faculty of Veterinary Medicine, University of Liège, Sart Tilman B43, 4000, Liege, Belgium.

Background: Despite the successful mapping of genes involved in the determinism of numerous traits, a large part of the genetic variation remains unexplained. A possible explanation is that the simple models used in many studies might not properly fit the actual underlying situations. Consequently, various methods have attempted to deal with the simultaneous mapping of genomic regions, assuming that these regions might interact, leading to a complex determinism for various traits. Despite some successes, no gold standard methodology has emerged. Actually, combining several interaction mapping methods might be a better strategy, leading to positive results over a larger set of situations. Our work is a step in that direction.

Results: We first have demonstrated why aggregating results from several distinct methods might increase the statistical power while controlling the type I error. We have illustrated the approach using 6 existing methods (namely: MDR, Boost, BHIT, KNN-MDR, MegaSNPHunter and AntEpiSeeker) on simulated and real data sets. We have used a very simple aggregation strategy: a majority vote across the best loci combinations identified by the individual methods. In order to assess the performances of our aggregation approach in problems where most individual methods tend to fail, we have simulated difficult situations where no marginal effects of individual genes exist and where genetic heterogeneity is present. we have also demonstrated the use of the strategy on real data, using a WTCCC dataset on rheumatoid arthritis. Since we have been using simplistic assumptions to infer the expected power of the aggregation method, the actual power we estimated from our simulations has turned out to be a bit smaller than theoretically expected. Results nevertheless have shown that grouping the results of several methods is advantageous in terms of power, accuracy and type I error control. Furthermore, as more methods should become available in the future, using a grouping strategy will become more advantageous since adding more methods seems to improve the performances of the aggregated method.

Conclusions: The aggregation of methods as a tool to detect genetic interactions is a potentially useful addition to the arsenal used in complex traits analyses.
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http://dx.doi.org/10.1186/s12859-018-2447-0DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6267805PMC
November 2018

Altered mitochondrial oxidative phosphorylation capacity in horses suffering from polysaccharide storage myopathy.

J Bioenerg Biomembr 2018 10 24;50(5):379-390. Epub 2018 Aug 24.

Equine Pole, Fundamental and Applied Research for Animals & Health (FARAH), Faculty of Veterinary Medicine, Liège, Belgium.

Polysaccharide storage myopathy (PSSM) is a widely described cause of exertional rhabdomyolysis in horses. Mitochondria play a central role in cellular energetics and are involved in human glycogen storage diseases but their role has been overlooked in equine PSSM. We hypothesized that the mitochondrial function is impaired in the myofibers of PSSM-affected horses. Nine horses with a history of recurrent exercise-associated rhabdomyolysis were tested for the glycogen synthase 1 gene (GYS1) mutation: 5 were tested positive (PSSM group) and 4 were tested negative (horses suffering from rhabdomyolysis of unknown origin, RUO group). Microbiopsies were collected from the gluteus medius (gm) and triceps brachii (tb) muscles of PSSM, RUO and healthy controls (HC) horses and used for histological analysis and for assessment of oxidative phosphorylation (OXPHOS) using high-resolution respirometry. The modification of mitochondrial respiration between HC, PSSM and RUO horses varied according to the muscle and to substrates feeding OXPHOS. In particular, compared to HC horses, the gm muscle of PSSM horses showed decreased OXPHOS- and electron transfer (ET)-capacities in presence of glutamate&malate&succinate. RUO horses showed a higher OXPHOS-capacity (with glutamate&malate) and ET-capacity (with glutamate&malate&succinate) in both muscles in comparison to the PSSM group. When expressed as ratios, our results highlighted a higher contribution of the NADH pathway (feeding electrons into Complex I) to maximal OXPHOS or ET-capacity in both rhabdomyolysis groups compared to the HC. Specific modifications in mitochondrial function might contribute to the pathogenesis of PSSM and of other types of exertional rhabdomyolyses.
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http://dx.doi.org/10.1007/s10863-018-9768-6DOI Listing
October 2018

Influence of a single dose of buprenorphine on rabbit (Oryctolagus cuniculus) gastrointestinal motility.

Vet Anaesth Analg 2018 Jul 29;45(4):510-519. Epub 2018 Mar 29.

Clinic for Birds, Rabbits and Rodents, Department of Clinical Sciences of Companion Animals and Equine, Fundamental and Applied Research for Animals & Health (FARAH), Faculty of Veterinary Medicine, University of Liège, Liège, Belgium.

Objective: To establish a noninvasive imaging protocol for rabbit gastrointestinal transit evaluation. To assess the effect of a single injection of buprenorphine on the digestive transit of rabbits via this new technique.

Study Design: Prospective, parallel study.

Animals: Fifteen specific pathogen-free male New Zealand White rabbits weighing 2.68 ± 0.28 kg.

Methods: A 10 mL kg barium meal was administered and the rabbits were subjected to serial radiographic and ultrasound examinations without treatment and 1 week later following a single intramuscular dose of 100 μg kg of buprenorphine. Radiographic data from the stomach and caecum were collected and assigned a retention score ranging from 0 (no barium) to 3 (large amount of barium). The resulting scores and pyloric and duodenal contraction counts were analysed using a mixed linear model and are expressed as least square mean (lsm) ± standard error. Transit was estimated based on the apparition time of faeces in the pelvic area and analysed using a Wilcoxon test. A p < 0.05 was considered significant.

Results: Buprenorphine treatment induced a higher lsm number of pyloric (1.73 ± 0.19 versus 0.78 ± 0.19, p < 0.01) and lsm duodenal contractions (17.35 ± 1.04 versus 13.44 ± 1.04, p < 0.01). Buprenorphine administration decreased the lsm barium retention score in the stomach (2.44 ± 0.05 versus 2.64 ± 0.05, p < 0.01), but had no effect on the lsm barium retention score in the caecum. The time to apparition of faeces in the pelvic area was not influenced by buprenorphine administration (p = 0.66).

Conclusions And Clinical Relevance: A single high dose of buprenorphine appears to have no adverse effect on gastrointestinal motility in healthy rabbits.
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http://dx.doi.org/10.1016/j.vaa.2018.01.011DOI Listing
July 2018

Age-based partitioning of individual genomic inbreeding levels in Belgian Blue cattle.

Genet Sel Evol 2017 12 22;49(1):92. Epub 2017 Dec 22.

Unit of Animal Genomics, GIGA-R & Faculty of Veterinary Medicine, University of Liège, B34 (+1) Avenue de l'Hôpital 1, 4000, Liège, Belgium.

Background: Inbreeding coefficients can be estimated either from pedigree data or from genomic data, and with genomic data, they are either global or local (when the linkage map is used). Recently, we developed a new hidden Markov model (HMM) that estimates probabilities of homozygosity-by-descent (HBD) at each marker position and automatically partitions autozygosity in multiple age-related classes (based on the length of HBD segments). Our objectives were to: (1) characterize inbreeding with our model in an intensively selected population such as the Belgian Blue Beef (BBB) cattle breed; (2) compare the properties of the model at different marker densities; and (3) compare our model with other methods.

Results: When using 600 K single nucleotide polymorphisms (SNPs), the inbreeding coefficient (probability of sampling an HBD locus in an individual) was on average 0.303 (ranging from 0.258 to 0.375). HBD-classes associated to historical ancestors (with small segments ≤ 200 kb) accounted for 21.6% of the genome length (71.4% of the total length of the genome in HBD segments), whereas classes associated to more recent ancestors accounted for only 22.6% of the total length of the genome in HBD segments. However, these recent classes presented more individual variation than more ancient classes. Although inbreeding coefficients obtained with low SNP densities (7 and 32 K) were much lower (0.060 and 0.093), they were highly correlated with those obtained at higher density (r = 0.934 and 0.975, respectively), indicating that they captured most of the individual variation. At higher SNP density, smaller HBD segments are identified and, thus, more past generations can be explored. We observed very high correlations between our estimates and those based on homozygosity (r = 0.95) or on runs-of-homozygosity (r = 0.95). As expected, pedigree-based estimates were mainly correlated with recent HBD-classes (r = 0.56).

Conclusions: Although we observed high levels of autozygosity associated with small HBD segments in BBB cattle, recent inbreeding accounted for most of the individual variation. Recent autozygosity can be captured efficiently with low-density SNP arrays and relatively simple models (e.g., two HBD classes). The HMM framework provides local HBD probabilities that are still useful at lower SNP densities.
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http://dx.doi.org/10.1186/s12711-017-0370-xDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5741860PMC
December 2017

Moku Virus in Invasive Asian Hornets, Belgium, 2016.

Emerg Infect Dis 2017 12;23(12):2109-2112

We report the detection of Moku virus in invasive Asian hornets (Vespa velutina nigrithorax) in Belgium. This constitutes an unexpected report of this iflavirus outside Hawaii, USA, where it was recently described in social wasps. Although virulence of Moku virus is unknown, its potential spread raises concern for European honeybee populations.
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http://dx.doi.org/10.3201/eid2312.171080DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5708231PMC
December 2017

Host DNA released by NETosis promotes rhinovirus-induced type-2 allergic asthma exacerbation.

Nat Med 2017 06 1;23(6):681-691. Epub 2017 May 1.

Airway Disease Infection Section, National Heart and Lung Institute (NHLI), Imperial College London, London, UK.

Respiratory viral infections represent the most common cause of allergic asthma exacerbations. Amplification of the type-2 immune response is strongly implicated in asthma exacerbation, but how virus infection boosts type-2 responses is poorly understood. We report a significant correlation between the release of host double-stranded DNA (dsDNA) following rhinovirus infection and the exacerbation of type-2 allergic inflammation in humans. In a mouse model of allergic airway hypersensitivity, we show that rhinovirus infection triggers dsDNA release associated with the formation of neutrophil extracellular traps (NETs), known as NETosis. We further demonstrate that inhibiting NETosis by blocking neutrophil elastase or by degrading NETs with DNase protects mice from type-2 immunopathology. Furthermore, the injection of mouse genomic DNA alone is sufficient to recapitulate many features of rhinovirus-induced type-2 immune responses and asthma pathology. Thus, NETosis and its associated extracellular dsDNA contribute to the pathogenesis and may represent potential therapeutic targets of rhinovirus-induced asthma exacerbations.
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http://dx.doi.org/10.1038/nm.4332DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5821220PMC
June 2017

The Major Envelope Glycoprotein of Murid Herpesvirus 4 Promotes Sexual Transmission.

J Virol 2017 07 9;91(13). Epub 2017 Jun 9.

Immunology-Vaccinology, Department of Infectious and Parasitic Diseases, Faculty of Veterinary Medicine-Fundamental and Applied Research for Animals and Health (FARAH), University of Liège, Liège, Belgium

Gammaherpesviruses are important human and animal pathogens. Infection control has proven difficult because the key process of transmission is ill understood. Murid herpesvirus 4 (MuHV-4), a gammaherpesvirus of mice, is transmitted sexually. We show that this depends on the major virion envelope glycoprotein gp150. gp150 is redundant for host entry, and , it regulates rather than promotes cell binding. We show that gp150-deficient MuHV-4 reaches and replicates normally in the female genital tract after nasal infection but is poorly released from vaginal epithelial cells and fails to pass from the female to the male genital tract during sexual contact. Thus, we show that the regulation of virion binding is a key component of spontaneous gammaherpesvirus transmission. Gammaherpesviruses are responsible for many important diseases in both animals and humans. Some important aspects of their life cycle are still poorly understood. Key among these is viral transmission. Here we show that the major envelope glycoprotein of murid herpesvirus 4 functions not in entry or dissemination but in virion release to allow sexual transmission to new hosts.
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http://dx.doi.org/10.1128/JVI.00235-17DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5469271PMC
July 2017

KNN-MDR: a learning approach for improving interactions mapping performances in genome wide association studies.

BMC Bioinformatics 2017 Mar 21;18(1):184. Epub 2017 Mar 21.

Department of Biostatistics, Faculty of Veterinary Medicine, FARAH, University of Liège, Sart Tilman B43, 4000, Liege, Belgium.

Background: Finding epistatic interactions in large association studies like genome-wide association studies (GWAS) with the nowadays-available large volume of genomic data is a challenging and largely unsolved issue. Few previous studies could handle genome-wide data due to the intractable difficulties met in searching a combinatorial explosive search space and statistically evaluating epistatic interactions given a limited number of samples. Our work is a contribution to this field. We propose a novel approach combining K-Nearest Neighbors (KNN) and Multi Dimensional Reduction (MDR) methods for detecting gene-gene interactions as a possible alternative to existing algorithms, e especially in situations where the number of involved determinants is high. After describing the approach, a comparison of our method (KNN-MDR) to a set of the other most performing methods (i.e., MDR, BOOST, BHIT, MegaSNPHunter and AntEpiSeeker) is carried on to detect interactions using simulated data as well as real genome-wide data.

Results: Experimental results on both simulated data and real genome-wide data show that KNN-MDR has interesting properties in terms of accuracy and power, and that, in many cases, it significantly outperforms its recent competitors.

Conclusions: The presented methodology (KNN-MDR) is valuable in the context of loci and interactions mapping and can be seen as an interesting addition to the arsenal used in complex traits analyses.
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http://dx.doi.org/10.1186/s12859-017-1599-7DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5361736PMC
March 2017

COMPARISON BETWEEN SEDATION AND GENERAL ANESTHESIA FOR HIGH RESOLUTION COMPUTED TOMOGRAPHIC CHARACTERIZATION OF CANINE IDIOPATHIC PULMONARY FIBROSIS IN WEST HIGHLAND WHITE TERRIERS.

Vet Radiol Ultrasound 2017 May 23;58(3):284-294. Epub 2017 Feb 23.

Department of Clinical Sciences, Fundamental and Applied Research for Animals & Health (FARAH), University of Liège, 4000, Liège, Belgium.

Canine idiopathic pulmonary fibrosis is a progressive interstitial lung disease mainly affecting West Highland white terriers. Thoracic high-resolution computed tomographic (T-HRCT) findings for Canine idiopathic pulmonary fibrosis acquired under general anesthesia have been described previously. However, the use of general anesthesia may be contraindicated for some affected dogs. Sedation may allow improved speed and safety, but it is unknown whether sedation would yield similar results in identification and grading of Canine idiopathic pulmonary fibrosis lesions. The aim of this prospective, observational, method-comparison, case-control study was to compare findings from T-HRCT images acquired under sedation versus general anesthesia for West Highland white terriers affected with Canine idiopathic pulmonary fibrosis (n = 11) and age-matched controls (n = 9), using the glossary of terms of the Fleischner Society and a scoring system. Ground-glass opacity was identified in all affected West Highland white terriers for both sedation and general anesthesia acquisitions, although the Ground-glass opacity extent varied significantly between the two acquisitions (P < 0.001). Ground-glass opacity was the sole lesion observed in control dogs (n = 6), but was less extensive compared with affected West Highland white terriers. Identification and grading of a mosaic attenuation pattern differed significantly between acquisitions (P < 0.001). Identification of lesions such as consolidations, nodules, parenchymal and subpleural bands, bronchial wall thickening, and bronchiectasis did not differ between acquisitions. The present study demonstrated that T-HRCT obtained under sedation may provide different information than T-HRCT obtained under general anesthesia for identification and grading of some Canine idiopathic pulmonary fibrosis lesions, but not all of them. These differences should be taken into consideration when general anesthesia is contraindicated and sedation is necessary for evaluating West Highland white terriers with Canine idiopathic pulmonary fibrosis.
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http://dx.doi.org/10.1111/vru.12481DOI Listing
May 2017

Conserved Fever Pathways across Vertebrates: A Herpesvirus Expressed Decoy TNF-α Receptor Delays Behavioral Fever in Fish.

Cell Host Microbe 2017 Feb;21(2):244-253

Immunology-Vaccinology, FARAH, Faculty of Veterinary Medicine, University of Liège, Liège 4000, Belgium. Electronic address:

Both endotherms and ectotherms (e.g., fish) increase their body temperature to limit pathogen infection. Ectotherms do so by moving to warmer places, hence the term "behavioral fever." We studied the manifestation of behavioral fever in the common carp infected by cyprinid herpesvirus 3, a native carp pathogen. Carp maintained at 24°C died from the infection, whereas those housed in multi-chamber tanks encompassing a 24°C-32°C gradient migrated transiently to the warmest compartment and survived as a consequence. Behavioral fever manifested only at advanced stages of infection. Consistent with this, expression of CyHV-3 ORF12, encoding a soluble decoy receptor for TNF-α, delayed the manifestation of behavioral fever and promoted CyHV-3 replication in the context of a temperature gradient. Injection of anti-TNF-α neutralizing antibodies suppressed behavioral fever, and decreased fish survival in response to infection. This study provides a unique example of how viruses have evolved to alter host behavior to increase fitness.
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http://dx.doi.org/10.1016/j.chom.2017.01.010DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5301049PMC
February 2017

Virucidal Efficacy of a Hydrogen Peroxide Nebulization Against Murine Norovirus and Feline Calicivirus, Two Surrogates of Human Norovirus.

Food Environ Virol 2016 12 6;8(4):275-282. Epub 2016 Jul 6.

Veterinary Virology and Animal Viral Diseases, Fundamental and Applied Research for Animals & Health (FARAH), Faculty of Veterinary Medicine, University of Liège, 4000, Liège, Belgium.

Human noroviruses (HuNoV) are amongst the leading causes of acute non-bacterial gastroenteritis in humans and can be transmitted via person-to-person contact, via contact with contaminated surfaces or by consumption of contaminated food. Contaminated surfaces in healthcare settings contribute to the transmission of viruses. No-touch automated room disinfection systems might prevent such a spread of contamination and thus their virucidal effect needs to be evaluated. The aim of this study was to assess the efficacy of a nebulization system spraying hydrogen peroxide on two main surrogates of HuNoV, namely murine norovirus (MNV) and feline calicivirus (FCV). The viruses were dried on cover glasses and on stainless steel discs and exposed to nebulization. The number of infectious viral particles and genomic copies before and after the nebulization was compared. The efficacy in reducing infectivity of both surrogates was demonstrated. For the infectious viral titre of MNV and FCV, a log reduction factor ≥4.84 and 4.85 was observed after nebulization, respectively, for tests on cover glasses and ≥3.90 and 5.30, respectively, for tests on stainless steel discs. Only low reductions in genomic copy numbers were observed for both surrogates. The nebulization of hydrogen peroxide showed a clear virucidal effect on both HuNoV surrogates, MNV and FCV, on two different carriers and the use of nebulization should be promoted in complementarity with conventional disinfection methods in healthcare settings and food processing facilities to reduce viral load and spread of contamination.
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http://dx.doi.org/10.1007/s12560-016-9253-5DOI Listing
December 2016

Comparison of 4 point-of-care blood gas analyzers for arterial blood gas analysis in healthy dogs and dogs with cardiopulmonary disease.

J Vet Emerg Crit Care (San Antonio) 2016 05 8;26(3):352-9. Epub 2016 Apr 8.

Department of Clinical Sciences, Faculty of Veterinary Medicine, University of Liege, Liège, Belgium.

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http://dx.doi.org/10.1111/vec.12469DOI Listing
May 2016

Generation of a soluble recombinant trimeric form of bovine CD40L and its potential use as a vaccine adjuvant in cows.

Vet Immunol Immunopathol 2015 Nov 28;168(1-2):1-13. Epub 2015 Sep 28.

Laboratory of Cellular and Molecular Immunology, GIGA-Research, University of Liège, 1 Avenue de l'Hôpital (B34), Sart Tilman, Liège, B-4000, Belgium. Electronic address:

Vaccination is the most cost-effective way to control infectious diseases in cattle. However, many infectious diseases leading to severe economical losses worldwide still remain for which a really effective and safe vaccine is not available. These diseases are most often due to intracellular pathogens such as bacteria or viruses, which are, by their localization, protected from antibiotics and/or CD4(+) T cell-dependent humoral responses. We therefore postulated that strategies leading to induction of not only CD4(+) T cell responses but also CD8(+) cytotoxic T lymphocyte (CTL) responses against infected cells should be privileged in the development of new vaccines against problematic intracellular pathogens in bovines. CD40 signaling in antigen-presenting cells may lead to the induction of robust CD4-independent CTL responses and several studies, especially in mice, have used CD40 stimulation to promote CD8(+) T cell-mediated immunity. For example, we have recently shown that immunization of mice with heat-killed Staphylococcus aureus (HKSA) and agonistic anti-CD40 monoclonal antibodies elicits strong CTL responses capable of protecting mice from subsequent staphylococcal mastitis. Unfortunately, there is at present no tool available to efficiently stimulate CD40 in cattle. In this study, we therefore first produced a soluble recombinant trimeric form of the natural bovine CD40 ligand (sboCD40LT). We then observed that sboCD40LT was able to potently stimulate bovine cells in vitro. Finally, we provide evidence that immunization of cows with sboCD40LT combined with HKSA was able to significantly increase the number of both HKSA-specific CD4(+) and CD8(+) T cells in the draining lymph nodes. In conclusion, we suggest that this new molecular tool could help in the development of vaccine strategies against bovine diseases caused by intracellular pathogens.
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http://dx.doi.org/10.1016/j.vetimm.2015.09.011DOI Listing
November 2015

Ectopic Expression of Retrotransposon-Derived PEG11/RTL1 Contributes to the Callipyge Muscular Hypertrophy.

PLoS One 2015 16;10(10):e0140594. Epub 2015 Oct 16.

Unit of Animal Genomics, GIGA Research Center and Faculty of Veterinary Medicine, University of Liège, 1 Avenue de l'Hôpital, Liège, Belgium.

The callipyge phenotype is an ovine muscular hypertrophy characterized by polar overdominance: only heterozygous +Mat/CLPGPat animals receiving the CLPG mutation from their father express the phenotype. +Mat/CLPGPat animals are characterized by postnatal, ectopic expression of Delta-like 1 homologue (DLK1) and Paternally expressed gene 11/Retrotransposon-like 1 (PEG11/RTL1) proteins in skeletal muscle. We showed previously in transgenic mice that ectopic expression of DLK1 alone induces a muscular hypertrophy, hence demonstrating a role for DLK1 in determining the callipyge hypertrophy. We herein describe newly generated transgenic mice that ectopically express PEG11 in skeletal muscle, and show that they also exhibit a muscular hypertrophy phenotype. Our data suggest that both DLK1 and PEG11 act together in causing the muscular hypertrophy of callipyge sheep.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0140594PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4608697PMC
June 2016

Comparative Virucidal Efficacy of Seven Disinfectants Against Murine Norovirus and Feline Calicivirus, Surrogates of Human Norovirus.

Food Environ Virol 2016 Mar 7;8(1):1-12. Epub 2015 Oct 7.

Veterinary Virology and Animal Viral Diseases, Fundamental and Applied Research for Animals & Health (FARAH), Faculty of Veterinary Medicine, University of Liège, 4000, Liège, Belgium.

Human noroviruses (HuNoV) are the leading cause of acute non-bacterial gastroenteritis in humans and can be transmitted either by person-to-person contact or by consumption of contaminated food. A knowledge of an efficient disinfection for both hands and food-contact surfaces is helpful for the food sector and provides precious information for public health. The aim of this study was to evaluate the effect of seven disinfectants belonging to different groups of biocides (alcohol, halogen, oxidizing agents, quaternary ammonium compounds, aldehyde and biguanide) on infectious viral titre and on genomic copy number. Due to the absence of a cell culture system for HuNoV, two HuNoV surrogates, such as murine norovirus and feline calicivirus, were used and the tests were performed in suspension, on gloves and on stainless steel discs. When, as criteria of efficacy, a log reduction >3 of the infectious viral titre on both surrogates and in the three tests is used, the most efficacious disinfectants in this study appear to be biocidal products B, C and D, representing the halogens, the oxidizing agents group and a mix of QAC, alcohol and aldehyde, respectively. In addition, these three disinfectants also elicited a significant effect on genomic copy number for both surrogate viruses and in all three tests. The results of this study demonstrate that a halogen compound, oxidizing agents and a mix of QAC, alcohol and aldehyde are advisable for HuNoV disinfection of either potentially contaminated surfaces or materials in contact with foodstuffs.
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http://dx.doi.org/10.1007/s12560-015-9216-2DOI Listing
March 2016

Assessment of CCL2 and CXCL8 chemokines in serum, bronchoalveolar lavage fluid and lung tissue samples from dogs affected with canine idiopathic pulmonary fibrosis.

Vet J 2015 Oct 4;206(1):75-82. Epub 2015 Jun 4.

Faculty of Veterinary Medicine, University of Liège, Bd de Colonster, Liège, Belgium.

Canine idiopathic pulmonary fibrosis (CIPF) is a progressive disease of the lung parenchyma that is more prevalent in dogs of the West Highland white terrier (WHWT) breed. Since the chemokines (C-C motif) ligand 2 (CCL2) and (C-X-C motif) ligand 8 (CXCL8) have been implicated in pulmonary fibrosis in humans, the aim of the present study was to investigate whether these same chemokines are involved in the pathogenesis of CIPF. CCL2 and CXCL8 concentrations were measured by ELISA in serum and bronchoalveolar lavage fluid (BALF) from healthy dogs and WHWTs affected with CIPF. Expression of the genes encoding CCL2 and CXCL8 and their respective receptors, namely (C-C motif) receptor 2 (CCR2) and (C-X-C motif) receptor 2 (CXCR2), was compared in unaffected lung tissue and biopsies from dogs affected with CIPF by quantitative PCR and localisation of CCL2 and CXCL8 proteins were determined by immunohistochemistry. Significantly greater CCL2 and CXCL8 concentrations were found in the BALF from WHWTs affected with CIPF, compared with healthy dogs. Significantly greater serum concentrations of CCL2, but not CXCL8, were found in CIPF-affected dogs compared with healthy WHWTs. No differences in relative gene expression for CCL2, CXCL8, CCR2 or CXCR2 were observed when comparing lung biopsies from control dogs and those affected with CIPF. In affected lung tissues, immunolabelling for CCL2 and CXCL8 was observed in bronchial airway epithelial cells in dogs affected with CIPF. The study findings suggest that both CCL2 and CXCL8 are involved in the pathogenesis of CIPF. Further studies are required to determine whether these chemokines might have a clinical use as biomarkers of fibrosis or as targets for therapeutic intervention.
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http://dx.doi.org/10.1016/j.tvjl.2015.06.001DOI Listing
October 2015

Functional analysis of the three HMA4 copies of the metal hyperaccumulator Arabidopsis halleri.

J Exp Bot 2015 Sep 4;66(19):5783-95. Epub 2015 Jun 4.

Functional Genomics and Plant Molecular Imaging, Center for Protein Engineering (CIP), Department of Life Sciences, University of Liège, B-4000 Liège, Belgium PhytoSYSTEMS, University of Liège, B-4000 Liège, Belgium

In Arabidopsis halleri, the HMA4 gene has an essential function in Zn/Cd hypertolerance and hyperaccumulation by mediating root-to-shoot translocation of metals. Constitutive high expression of AhHMA4 results from a tandem triplication and cis-activation of the promoter of all three copies. The three AhHMA4 copies possess divergent promoter sequences, but highly conserved coding sequences, and display identical expression profiles in the root and shoot vascular system. Here, an AhHMA4::GFP fusion was expressed under the control of each of the three A. halleri HMA4 promoters in a hma2hma4 double mutant of A. thaliana to individually examine the function of each AhHMA4 copy. The protein showed non-polar localization at the plasma membrane of the root pericycle cells of both A. thaliana and A. halleri. The expression of each AhHMA4::GFP copy complemented the severe Zn-deficiency phenotype of the hma2hma4 mutant by restoring root-to-shoot translocation of Zn. However, each copy had a different impact on metal homeostasis in the A. thaliana genetic background: AhHMA4 copies 2 and 3 were more highly expressed and provided higher Zn tolerance in roots and accumulation in shoots than copy 1, and AhHMA4 copy 3 also increased Cd tolerance in roots. These data suggest a certain extent of functional differentiation among the three A. halleri HMA4 copies, stemming from differences in expression levels rather than in expression profile. HMA4 is a key node of the Zn homeostasis network and small changes in expression level can have a major impact on Zn allocation to root or shoot tissues.
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http://dx.doi.org/10.1093/jxb/erv280DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4566976PMC
September 2015

Effect of storage and cooking on the fatty acid profile of omega-3 enriched eggs and pork meat marketed in Belgium.

Food Sci Nutr 2015 Mar 30;3(2):140-52. Epub 2014 Dec 30.

Department of Food Sciences, Laboratory of Food Analysis, FARAH - Veterinary Public Health, University of Liège B43bis Bld de Colonster 20, Sart-Tilman, B-4000, Liège, Belgium.

The fatty acids (FA) profile was determined in n-3 enriched (Columbus™) Belgian eggs and pork in order to evaluate to what extent the n-3 fatty acids, which are very sensitive to oxidation, are resistant to storage or cooking. In standard eggs or pork, no change of the fatty acid profile was observed after storage or cooking without culinary fat, as well as in Columbus™ eggs and pork after storage. Some cooking processes (eggs in custard and meat in oven) induced a slight significant loss of n-3 fatty acids in Columbus™ eggs or pork (11.1% in fat from eggs cooked in custard vs. 15.3% in raw Columbus™ eggs and 11.0% in fat from oven cooked meat vs. 11.6% in raw Columbus™ meat). As expected, when Columbus™ pork is cooked with culinary fat, its fatty acid profile is modified according to the nature of the fat used.
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http://dx.doi.org/10.1002/fsn3.197DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4376408PMC
March 2015

Rational development of an attenuated recombinant cyprinid herpesvirus 3 vaccine using prokaryotic mutagenesis and in vivo bioluminescent imaging.

PLoS Pathog 2015 Feb 20;11(2):e1004690. Epub 2015 Feb 20.

Immunology-Vaccinology, Department of Infectious and Parasitic Diseases, Fundamental and Applied Research for Animals & Health (FARAH), Faculty of Veterinary Medicine, University of Liège, Liège, Belgium.

Cyprinid herpesvirus 3 (CyHV 3) is causing severe economic losses worldwide in common and koi carp industries, and a safe and efficacious attenuated vaccine compatible with mass vaccination is needed. We produced single deleted recombinants using prokaryotic mutagenesis. When producing a recombinant lacking open reading frame 134 (ORF134), we unexpectedly obtained a clone with additional deletion of ORF56 and ORF57. This triple deleted recombinant replicated efficiently in vitro and expressed an in vivo safety/efficacy profile compatible with use as an attenuated vaccine. To determine the role of the double ORF56-57 deletion in the phenotype and to improve further the quality of the vaccine candidate, a series of deleted recombinants was produced and tested in vivo. These experiments led to the selection of a double deleted recombinant lacking ORF56 and ORF57 as a vaccine candidate. The safety and efficacy of this strain were studied using an in vivo bioluminescent imaging system (IVIS), qPCR, and histopathological examination, which demonstrated that it enters fish via skin infection similar to the wild type strain. However, compared to the parental wild type strain, the vaccine candidate replicated at lower levels and spread less efficiently to secondary sites of infection. Transmission experiments allowing water contamination with or without additional physical contact between fish demonstrated that the vaccine candidate has a reduced ability to spread from vaccinated fish to naïve sentinel cohabitants. Finally, IVIS analyses demonstrated that the vaccine candidate induces a protective mucosal immune response at the portal of entry. Thus, the present study is the first to report the rational development of a recombinant attenuated vaccine against CyHV 3 for mass vaccination of carp. We also demonstrated the relevance of the CyHV 3 carp model for studying alloherpesvirus transmission and mucosal immunity in teleost skin.
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http://dx.doi.org/10.1371/journal.ppat.1004690DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4336323PMC
February 2015

Normal bacterial conjunctival flora in the Huacaya alpaca (Vicugna pacos).

Vet Ophthalmol 2016 Jan 9;19(1):22-8. Epub 2015 Jan 9.

Department of Clinical Sciences, Faculty of Veterinary Medicine, University of Liège, Boulevard de Colonster 20 B44, Liège, 4000, Belgium.

Objective: To describe the bacterial flora of the normal conjunctiva of Huacaya alpacas (Vicugna pacos) and to determine the effect of age and gender on this flora.

Animals Studied: Fifty Huacaya alpacas.

Procedures: After a complete ophthalmic examination, conjunctival swabs were obtained from both eyes and cultured for aerobic and anaerobic bacteria. Logistic and Poisson regression analyses were used to evaluate the effect of age and gender on bacterial isolation.

Results: Four animals were excluded because of signs of external ocular disease. Of the remaining 46 alpacas, bacteria were recovered from 96.7% (89/92) of the eyes. A total of 190 bacterial isolates were cultured with a mean of 2.1 bacterial isolates per eye. The majority of isolates (70%) were Gram-positive. Staphylococcus xylosus (44/190: 23.2%) predominated, followed by viridans streptococci (32/190: 16.8%) and Pantoea agglomerans (24/190: 12.6%). Other frequently isolated bacteria included Rothia mucilaginosa (12/190: 6.3%), Staphylococcus equorum (12/190: 6.3%), Bacillus species (9/190: 4.7%), Moraxella ovis (9/190: 4.7%), and Moraxella catarrhalis (6/190: 3.2%). Statistical analysis showed that alpacas harboring viridans streptococci and Moraxella species were significantly younger. Gender did not significantly affect type of bacterial isolation. There appeared to be no significant effect of age or gender on number of bacteria isolated.

Conclusions: Gram-positive aerobes were most commonly cultured, with S. xylosus and viridans streptococci predominating. To the best of the authors' knowledge, this is the first report describing the presence of Moraxella species in the healthy conjunctival sac of alpacas. Alpacas harboring viridans streptococci and Moraxella species were significantly younger.
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http://dx.doi.org/10.1111/vop.12248DOI Listing
January 2016

Sensitivity and permissivity of Cyprinus carpio to cyprinid herpesvirus 3 during the early stages of its development: importance of the epidermal mucus as an innate immune barrier.

Vet Res 2014 Oct 4;45:100. Epub 2014 Oct 4.

Immunology-Vaccinology, Department of Infectious and Parasitic Diseases (B43b), Fundamental and Applied Research for Animals & Health, Faculty of Veterinary Medicine, University of Liège, 4000, Liège, Belgium.

Cyprinid herpesvirus 3 (CyHV-3) causes a lethal disease in common and koi carp (Cyprinus carpio). The present study investigated the ability of CyHV-3 to infect common carp during the early stages of its development (from embryos to fingerlings) after inoculation by immersion in water containing the virus. Fish were inoculated at different times after hatching with a pathogenic recombinant CyHV-3 strain expressing luciferase. The sensitivity and permissivity of carp to CyHV-3 were investigated using in vivo bioluminescence imaging. The susceptibility of carp to CyHV-3 disease was investigated by measuring the survival rate. Carp were sensitive and permissive to CyHV-3 infection and susceptible to CyHV-3 disease at all stages of development, but the sensitivity of the two early developmental stages (embryo and larval stages) was limited compared to later stages. The lower sensitivity observed for the early developmental stages was due to stronger inhibition of viral entry into the host by epidermal mucus. In addition, independent of the developmental stage at which inoculation was performed, the localization of light emission suggested that the skin is the portal of CyHV-3 entry. Taken together, the results of the present study demonstrate that carp are sensitive and permissive to CyHV-3 at all stages of development and confirm that the skin is the major portal of entry after inoculation by immersion in infectious water. The results also stress the role of epidermal mucus as an innate immune barrier against pathogens even and especially at the early stages of development.
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http://dx.doi.org/10.1186/s13567-014-0100-0DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4198741PMC
October 2014