References of "Portetelle, Daniel"
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See detailIntegrated “omics” approaches to investigate the chemical aspects of symbiosis in termites and potential application in ligno-cellulosic use.
Bauwens, Julien ULg; Matteotti, Christel ULg; Brognaux, Alison ULg et al

Scientific conference (2010, May 05)

Cellulosic bioethanol could be one of the solutions to satisfy the increasing demand in renewable energy. The most limitative problem is the efficiency of cellulose transformation into fermentable sugars ... [more ▼]

Cellulosic bioethanol could be one of the solutions to satisfy the increasing demand in renewable energy. The most limitative problem is the efficiency of cellulose transformation into fermentable sugars. Investigations to select new glycosyl hydrolases are an interesting approach that constitutes a potential opportunity to improve the valorization of lignocellulosic materials. Three major types of glycosyl hydolases are generally produced by organism’s that are able to efficiently use cellulosic compounds: the endoglucanases, the exoglucanases/cellobiohydrolases and the β-glucosidases. In the ability to transform lignocellulosic materials by animals, symbioses are generally observed with a range of micro-organisms including bacteria, protists and/or fungi that largely (or completely) contribute to the production of the needed enzymatic complexes. In termites, such active enzymes are produced in the insect digestive tract, by the termite insect itself or by symbiotic organisms. Within lower termites gut, such as in our model Reticulitermes santonensis (Feytaud), protists and bacteria are associated and involved in a complex symbiotic system. To investigate the respective role of the insect and different groups of symbionts, multidisciplinary “omics” approaches were here developed including proteomics (ESI-LC-MS-MS, 2D-Dige gel coupled with MALDI-TOF mass spectrometry for protein identification), genomics (with a metagenomic approach based on large cDNA bank construction), metabolomics (LC-MS stragety for carbohydrate degradation product characterization). Moreover, microorganism isolation was used to investigate and characterize glycosyl hydrolases diversity and activity in R. santonensis. The integration of this broad range of “omics” techniques allowed characterizing the role of symbionts in insects in a fundamental approach and to invtigate the chemical ecology of xylophagous insects but also corresponding to an efficient way to promote the selection of efficient enzymatic activities to potentially produce biofuels based on the use of existing lignocellulosic materials. [less ▲]

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See detailEffect of bovine colostrum on the serum insulin-like growth factor-I (IGF-I), the IGF binding proteins-2 and -3 and the thyroid hormones in weaning piglets
Boudry, Christelle ULg; Dehoux, Jean-Paul; Colinet, Frédéric ULg et al

in Archiv Tierzucht (2010), 53(6), 675-688

This study examined the effect of a bovine colostrum supplementation on growth performance, feed intake and the hormonal response of piglets at weaning. Ninety-six newly-weaned piglets were assigned for ... [more ▼]

This study examined the effect of a bovine colostrum supplementation on growth performance, feed intake and the hormonal response of piglets at weaning. Ninety-six newly-weaned piglets were assigned for four weeks to one of the two treatments: Control (diet with bovine milk whey) and Colostrum (diet with bovine colostrum whey) treatments. The supplements were incorporated in a commercial diet at 20 g/kg during the first 2 weeks after weaning and lowered to 10 g/kg for the next 2 weeks. Body weight and feed intake were measured weekly. Blood samples were taken weekly for determination of circulating IGF-I, its binding proteins and the thyroid hormones (T3 and T4). During the first week of the trial, the Colostrum-fed piglets presented improved growth performance, feed intake and feed efficiency and a higher concentration in circulating IGF-I (+ 15 %) compared to the Control piglets. In both treatments, the circulating thyroid hormones were reduced by weaning and the levels measured at weaning were recovered earlier by the Colostrum-fed piglets compared to the Control group (P < 0.05). It is concluded that hormonal response observed after the bovine colostrum supplementation is, at least in part, consequent of the positive action of bovine colostrum on the feed intake. [less ▲]

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See detailImmunisation passive du poulet de chair vis-à-vis des salmonelles à l'aide d'anticorps du jaune d'oeuf
Marcq, Christopher ULg; Thewis, André ULg; Portetelle, Daniel ULg et al

in Impacts de l'alimentation sur la santé animale : nouveaux développements (2009, October 14)

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See detailEffets biologiques et immunitaires du colostrum bovin sur le porcelet au sevrage
Boudry, Christelle ULg; Dehoux, Jean-Paul; Wavreille, José et al

in 9éme Journée des Productions porcines et avicoles "Impact de l'alimentation sur la santé animale : nouveaux développement" (2009, October 14)

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See detailPotential of Dried Egg Yolk as a Source of Immunoglobulins to Control Salmonella in the Gastrointestinal Tract of the Broiler Chicken
Marcq, Christopher ULg; Portetelle, Daniel ULg; Chalghoumi, RAJA ULg et al

in 17th European Symposium on Poultry Nutrition : Proceedings & Abstracts (2009, August)

Egg yolk immunoglobulins (IgY) are considered as a promising tool of establishing passive immunity against enteric pathogens (e.g. Salmonella) in poultry (Kovacs-Nolan and Mine, 2005). In our previous ... [more ▼]

Egg yolk immunoglobulins (IgY) are considered as a promising tool of establishing passive immunity against enteric pathogens (e.g. Salmonella) in poultry (Kovacs-Nolan and Mine, 2005). In our previous works, in-feed incorporation of freeze-dried yolk powder (FYP) improved performances of Salmonella-infected broilers (Marcq et al., 2009). Nevertheless, no extra value could be attributed to the presence of specific IgY when a comparison was done between impact of hyperimmune or non immune FYP both concerning growth performances and Salmonella infection. We hypothesized that these inconclusive in vivo results were related to the sensitivity of IgY to gastrointestinal conditions. Egg yolks with high IgY titers directed against Salmonella Enteritidis and Typhimurium were obtained from laying hens immunized as previously described (Chalghoumi et al., 2008). Three feed additives derived from these eggs were produced: FYP, spray-dried yolk powder (SYP), and freeze-dried water-soluble fraction of yolk powder (WSFP). A force-feeding assay was realized on these additives with 48 five-week-old males Ross broiler chicken (Salmonella spp.-free status). Survival of undigested IgY and bioactive Fab fragments was evaluated in the intestinal tract by ELISA. Statistical analyses were done using GLM procedure of Minitab 15.1. Software. Differences were considered significant when P<0.05. As a result of the digestive process, the levels of total and specific undigested IgY found throughout the intestine were dramatically reduced for the three additives. For FYP, no difference was observed with intestinal contents of control animals (P>0.05) and for WSFP, which correspond to semi-purified IgY, the immunological activity reached the same level than that for SYP (P>0.05) whereas its initial level was almost ten times higher. The results suggest a protective effect of whole yolk on IgY with SYP but such effect was not observed with FYP. High levels of Fab fragments were identified in intestinal contents, highlighting the importance of protein digestion in the digestive tract and especially pepsin digestion. These Fab fragments conserve their immunological functionality and remained detectable in all intestinal segments including the caecum which represents the major site of Salmonella infection in poultry. These results can explain our previous challenge data and reveal that a protection treatment should be applied to dried egg yolk to improve the resistance of IgY to gastrointestinal conditions in broilers. [less ▲]

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See detailHen egg yolk antibodies (IgY), production and use for passive immunization against bacterial enteric infections in chicken : a review
Chalghoumi, Raja; Beckers, Yves ULg; Portetelle, Daniel ULg et al

in Biotechnologie, Agronomie, Société et Environnement = Biotechnology, Agronomy, Society and Environment [=BASE] (2009), 13(3), 295-308

Enteric infections caused by Salmonella remain a major public health burden worldwide. Poultry, particularly chickens, are known to be the main reservoir for this zoonotic pathogen. Therefore, the ... [more ▼]

Enteric infections caused by Salmonella remain a major public health burden worldwide. Poultry, particularly chickens, are known to be the main reservoir for this zoonotic pathogen. Therefore, the prevention and monitoring of Salmonella infection during the live phase may greatly reduce the contamination of poultry meat during slaughter and processing. With the ban on sub-therapeutic antibiotic usage in Europe and the increasingly strictness of the European legislation on food hygiene, passive immunization by oral administration of pathogen-specific hen egg yolk antibody (IgY) may be a useful and attractive alternative. This review offers summarized information about IgY production and the use of these antibodies for passive immunization, particularly in poultry [less ▲]

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See detailAdhesion and growth inhibitory effect of chicken egg yolk antibody (IgY) on Salmonella enterica serovars Enteritidis and Typhimurium in vitro.
Chalghoumi, Raja; Thewis, André ULg; Beckers, Yves ULg et al

in Foodborne Pathogens and Disease (2009), 6(5), 593-604

The protective effects of powder preparation of egg yolk immunoglobulin Y (IgY), specific to Salmonella Enteritidis and Salmonella Typhimurium outer membrane proteins (OMP), against these two Salmonella ... [more ▼]

The protective effects of powder preparation of egg yolk immunoglobulin Y (IgY), specific to Salmonella Enteritidis and Salmonella Typhimurium outer membrane proteins (OMP), against these two Salmonella sp. serovars were investigated in vitro in two different assays: adhesion-prevention and growth-inhibition. The adhesion-prevention assay was conducted using polarized monolayers of the human intestinal epithelial Caco-2 cell line. First, the conditions of Salmonella adherence to Caco-2 cells were optimized, and interferences of bacteria with the transepithelial electrical resistance (TER) of fully differentiated Caco-2 cell monolayers and the lactate dehydrogenase release upon exposure of the cells to Salmonella were evaluated. Both Salmonella sp. serovars were able to adhere to Caco-2 cells and decreased TER. Results from the adhesion-prevention assay demonstrated that specific IgY reduced the decrease in TER of the infected Caco-2 cell monolayers and blocked the Salmonella sp. adhesion in a concentration-dependent manner (p < 0.05). Nonspecific IgY also exhibited an inhibitory effect on these two parameters, but to a lesser extent than that of the specific IgY (p < 0.05). The protective effect of nonspecific IgY could be attributed to the low-density lipoprotein component of the water-soluble fraction of egg yolks that may not have been eliminated during ultrafiltration. The growth-inhibition assay revealed that specific IgY had an inhibitory effect on the bacterial growth, markedly during the late exponential phase, whereas nonspecific IgY failed to do so. Taken together, these results suggest that the in vitro growth inhibitory effect of specific IgY on Salmonella spp. resulted from the specific binding activity of these IgY to Salmonella sp. OMP. Passive immunization with Salmonella sp. OMP-specific IgY could thus be useful to prevent Salmonella colonization in broiler chickens and the subsequent carcass contamination during processing. [less ▲]

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See detailEffects of feed supplementation with specific hen egg yolk antibody (immunoglobin Y) on Salmonella species cecal colonization and growth performances of challenged broiler chickens
Chalghoumi, Raja; Marcq, Christopher ULg; Thewis, André ULg et al

in Poultry Science (2009), 88(10), 2081-2092

Anti-Salmonella spp. egg yolk antibodies (IgY) simultaneously directed against Salmonella Enteritidis and Salmonella Typhimurium were tested to determine if their inclusion in feed decreased Salmonella ... [more ▼]

Anti-Salmonella spp. egg yolk antibodies (IgY) simultaneously directed against Salmonella Enteritidis and Salmonella Typhimurium were tested to determine if their inclusion in feed decreased Salmonella spp. cecal colonization in experimentally infected broiler chickens. Egg yolk powder (EYP) was obtained by freeze-drying egg yolks containing anti-Salmonella spp. Immunoglobin Y was included in feed at 5 levels of concentration (0 to 5%). Feeds were formulated to similar nutrient levels and provided for ad libitum intake from d 1 to 28. Three days after initiation of feed treatments (d 4), chickens were co-challenged with equal numbers of Salmonella Enteritidis and Salmonella Typhimurium (2x10(6) cfu/bird). Cecal samples were recovered weekly over the experimental period (d 7 to 28) to enumerate Salmonella spp. The effect of anti-Salmonella spp. IgY feed supplementation on growth performance of infected chickens was also evaluated during the same period. In comparison with the positive control treatment (PC), treatments involving EYP (T1, T2, T3, T4, and T5), whether containing anti-Salmonella spp. IgY or not, significantly improved (P<0.05) the growth performance of challenged chickens, but without reaching the performance levels of nonchallenged chickens (NC1 and NC2). However, no link can be established between the enhancement in growth performance of challenged birds and their contamination levels by Salmonella because in-feed incorporation of EYP had no significant effect on cecal colonization by Salmonella. Furthermore, the comparison of the 5 anti-Salmonella spp. IgY concentration levels in feed did not reveal any anti-Salmonella spp. IgY concentration effect on growth performance and Salmonella cecal colonization. These results suggest that anti-Salmonella spp. IgY would undergo denaturation and degradation after their passage through the animal gastrointestinal tract and reveal that components of EYP other than specific antibodies have a beneficial effect on growth performance. [less ▲]

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See detailDéveloppement d’une stratégie d’immunisation passive du poulet de chair vis-à-vis de Salmonella Enteritidis et Typhimurium à l’aide d’anticorps du jaune d’œuf
Marcq, Christopher ULg; Chalghoumi, RAJA ULg; Beckers, Yves ULg et al

in 8èmes JRA : Synthèses et textes (2009)

The present study investigates the potential of oral immunotherapy using hen egg yolk immunoglobulins (IgY) as a strategy to reduce the impact of Salmonella contamination on broilers. In a first step ... [more ▼]

The present study investigates the potential of oral immunotherapy using hen egg yolk immunoglobulins (IgY) as a strategy to reduce the impact of Salmonella contamination on broilers. In a first step, hyperimmune eggs were obtained from laying hens immunized using Salmonella Enteritidis (SE) and Typhimurium (ST) outer membrane proteins in emulsion with Freund adjuvants. This led to the production of high levels of IgY antibodies directed against the two Salmonella serovars in egg yolks. Furthermore, no adverse affects were detected on mortality or laying rate in hens injected with this vaccine. Powders were obtained from these eggs by spray- or freeze-drying the whole yolk. In order to study the effect of these powders on broiler’s growth performances, a challenge trial was conducted. 384 Salmonella spp.-free day-of-hatch chickens received supplemented feed (5 % freeze-dried egg yolk powder) since arrival, and were infected at day four with 106 cfu of SE and ST per animal. We found a significant improvement in growth performances for the groups receiving the yolk-enriched diets. Nevertheless, none of the supplement concentrations allowed to raise the same body weight after 28 days of complementation than in uninfected broilers (p < 0,05). Interestingly, nonimmune egg yolk powder also exhibited a positive effect on performances of broilers experimentally infected with SE and ST. Our results suggest that passive immunization through egg yolk powders could be useful to reduce negative effects of Salmonella infection on broilers growth performances. [less ▲]

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See detailGenomic location of the bovine growth hormone secretagogue receptor (Ghsr) gene and investigation of genetic polymorphism
Colinet, Frédéric ULg; Vanderick, Sylvie ULg; Charloteaux, Benoît ULg et al

in Animal Biotechnology (2009), 20(1), 28-33

The growth hormone secretagogue receptor (GHSR) is involved in the regulation of energetic homeostasis and GH secretion. In this study, the bovine GHSR gene was mapped to BTA1 between BL26 and BMS4004 ... [more ▼]

The growth hormone secretagogue receptor (GHSR) is involved in the regulation of energetic homeostasis and GH secretion. In this study, the bovine GHSR gene was mapped to BTA1 between BL26 and BMS4004. Two different bovine GHSR CDS (GHSR1a and GHSR1b) were sequenced. Six polymorphisms (five SNPs and one 3-bp indel) were also identified, three of them leading to amino acid variations L24V, D194N, and Del R242. These variations are located in the extracellular N-terminal end, the exoloop 2, and the cytoloop 3 of the receptor, respectively. [less ▲]

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See detailGenetic analysis of lactoferrin content in bovine milk
Arnould, Valérie ULg; Soyeurt, Hélène ULg; Gengler, Nicolas ULg et al

in Journal of Dairy Science (2009), 92(5), 2151-2158

Bovine lactoferrin (LF) is mainly present in milk and shows important physiological and biological functions. The aim of this study was to estimate the heritability and correlation values of LF content in ... [more ▼]

Bovine lactoferrin (LF) is mainly present in milk and shows important physiological and biological functions. The aim of this study was to estimate the heritability and correlation values of LF content in bovine milk with different economic traits as milk yield (MY), fat and protein percentages, and somatic cell score (SCS). Variance components of the studied traits were estimated by REML using a multiple-trait mixed model. The obtained heritability (0.22) for LF content predicted using mid-infrared spectrometry (pLF) suggested the possibility of animal selection based on the increase of LF content in milk. The phenotypic and genetic correlation values calculated between pLF and SCS were moderate (0.31 and 0.24, respectively). Furthermore, a preliminary study of bovine LF gene polymorphism effects was performed on the same production traits. By PCR, all exons of the LF gene were amplified and then sequenced. Three new polymorphisms were detected in exon 2, exon 11, and intron 8. We examined the effects of LF gene polymorphisms of exons 2, 4, 9, 11, and 15, and intron 8 on pLF, MY, fat and protein percentages, and SCS. The different observed effects did not reach a significant level probably because of the characteristics of the studied population. However, the results were promising, and LF may be a potential indicator of mastitis. Further studies are necessary to evaluate the effect of genetic selection based on LF content on the improvement of mastitis resistance. [less ▲]

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See detailMolecular characterization of the bovine GHRL gene
Colinet, Frédéric ULg; Portetelle, Daniel ULg; Renaville, Robert ULg

in Archiv für Tierzucht = Archives Animal Breeding (2009), 52(1), 79-84

Bovine ghrelin, a 27 amino acid pepticle, has been identified in oxyntic glands of the abomasum. It is an endogenous ligand for growth hormone secretagogue receptor and stimulates food intake and growth ... [more ▼]

Bovine ghrelin, a 27 amino acid pepticle, has been identified in oxyntic glands of the abomasum. It is an endogenous ligand for growth hormone secretagogue receptor and stimulates food intake and growth hormone secretion. The bovine GHRL gene was completely sequenced and consists of five exons and four introns. Like mouse and human GHRL genes, we found that the bovine GHRL gene also contains a first non-coding exon of 21 bp. The bovine GHRL gene codes for 116 amino acid pepticle named preproghrelin which contains the ghrelin pepticle and another pepticle similar to obestatin. Sequence analysis revealed eight polymorphisms, which are located in the non-coding sequence of the gene. [less ▲]

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See detailIsolation and biomass production of a Saccharomyces cerevisiae strain binding copper and zinc ions
Stroobants, Aurore ULg; Delroisse, Jean-Marc; Delvigne, Frank ULg et al

in Applied Biochemistry and Biotechnology (2009), 157(1),

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