R Ducatelle

Ghent University, Gand, Flanders, Belgium

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Publications (474)1085.91 Total impact

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    ABSTRACT: Consumption of contaminated poultry meat is still an important cause of Salmonella infections in humans and there is a need for control methods that protect broilers from day-of-hatch until slaughter age against infection with Salmonella. Colonisation-inhibition, a concept in which a live Salmonella strain is orally administered to day-old chickens and protects against subsequent challenge, can potentially be used as control method. In this study, the efficacy of a Salmonella Typhimurium ΔhilAssrAfliG strain as a colonisation-inhibition strain for protection of broilers against Salmonella Typhimurium was evaluated. Administration of a Salmonella Typhimurium ΔhilAssrAfliG strain to day-old broiler chickens decreased faecal shedding and strongly reduced caecal and internal organ colonisation of a Salmonella Typhimurium challenge strain administered one day later using a seeder bird model. In addition, it was verified whether a colonisation-inhibition culture could be developed that protects against both Salmonella Enteritidis and Typhimurium. Therefore, the Salmonella Typhimurium ΔhilAssrAfliG strain was orally administered simultaneously with a Salmonella Enteritidis ΔhilAssrAfliG strain to day-old broiler chickens, which resulted in a decreased caecal and internal organ colonisation for both a Salmonella Enteritidis and a Salmonella Typhimurium challenge strain short after hatching, using a seeder bird model. The combined culture was not protective against Salmonella Paratyphi B varietas Java challenge, indicating serotype-specific protection mechanisms. The data suggest that colonisation-inhibition can potentially be used as a versatile control method to protect poultry against several Salmonella serotypes.
    Vaccine 06/2014; · 3.49 Impact Factor
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    ABSTRACT: VC2002, isolated from postweaning multisystemic wasting syndrome (PMWS)-affected pig, is a mixture of two porcine circovirus genotype 2b (PCV2b) viruses, K2 and K39. Preliminary experiments disclosed short-term adverse effects of K39, but not K2, on porcine foetuses. These findings led to the hypothesis that infection of immuno-incompetent foetuses with K2 confers a status of immunotolerance, and postnatal super-infection with K39 triggers PMWS. To explore this hypothesis, nine 55-day-old foetuses were inoculated in utero (three with K2-10(4.3)TCID50, three with K39-10(4.3)TCID50 and three with medium), and foeto-pathogenicity examined. At 21 days post-inoculation (dpi), K2 did not induce pathology, whereas pathological effects of K39 were evident. Twenty-four 45-day-old foetuses were subsequently inoculated to examine the long-term effect of K2, including six with K2-high dose-10(4.3)TCID50, six with K2-low dose-10(2.3)TCID50 and 12 mock-inoculated controls. Both doses resulted in five mummified foetuses and one live-born piglet each (69dpi). K2 was recovered from all mummies. K2 and K2-specific antibodies were not detected in serum of the two live-born piglets at birth, indicating full control of K2 infection. The K2-low dose-infected piglet was immunostimulated at day 2, but not the K2-high dose-infected piglet. Both non-stimulated and stimulated K2-infected piglets were super-inoculated with K39 at day 6 or 8 (taken as 0 days post super-inoculation). Low viral replication was observed in the non-stimulated K2-K39 piglet (up to 10(3.3)TCID50/g; identified as K39). In contrast, viral replication was extremely high in the stimulated K2-K39 piglet (up to 10(5.6)TCID50/g) and identified as K2, indicating that K2 infection is controlled during foetal life, but emerges after birth upon immunostimulation. However, none of the piglets showed any signs of PMWS.
    Virologica Sinica 06/2014; 29(3).
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    ABSTRACT: Helicobacter heilmannii is a zoonotic bacterium that has been associated with gastric disease in humans. In this study, mRNA expression of mucins was analyzed at several time-points in the stomach of BALB/c mice during a one year infection with this bacterium in which gastric disease progressed in severity. Markers for acid production by parietal cells and mucous metaplasia were also examined. In the first 9 weeks post-infection, mRNA expression of Muc6 was clearly upregulated in both the antrum and fundus of the stomach of H. heilmannii-infected mice. Interestingly, Muc13 was upregulated already at 1 day post-infection in the fundus of the stomach. Its expression level remained high in the stomach over the course of the infection. This mucin is, however, not expressed in a healthy stomach and a high expression of this mucin has so far only been described in gastric cancer. In the later stages of infection, mRNA expression of H(+)/K(+)-ATPase α/β and KCNQ1 decreased whereas the expression of Muc4, Tff2, Dmbt1 and PigR increased starting at 16 weeks post-infection onwards suggesting the existence of spasmolytic polypeptide-expressing metaplasia in the fundus of the stomach. Mucous metaplasia present in the mucosa surrounding low grade mucosa associated lymphoid tissue lymphoma-like lesions was also histologically confirmed. Our findings indicate that H. heilmannii infection causes severe gastric pathologies, alterations in the expression pattern of gastric mucins, such as Muc6 and Muc13, as well as a disruption in the gastric homeostasis by inducing loss of parietal cells resulting in the development of mucous metaplasia.
    Infection and Immunity 05/2014; · 4.16 Impact Factor
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    ABSTRACT: Eggs contaminated with Salmonella Enteritidis are an important source of human foodborne Salmonella infections. Salmonella Enteritidis is able to contaminate egg white during formation of the egg within the chicken oviduct, and it has developed strategies to withstand the antimicrobial properties of egg white to survive in this hostile environment. The mechanisms involved in the persistence of Salmonella Enteritidis in egg white are likely to be complex. To address this issue, a microarray-based transposon library screen was performed to identify genes necessary for survival of Salmonella Enteritidis in egg white at chicken body temperature. The majority of identified genes belonged to the lipopolysaccharide biosynthesis pathway. Additionally, we provide evidence that the serine protease/heat shock protein (HtrA) appears essential for the survival of Salmonella Enteritidis in egg white at chicken body temperature.
    Poultry Science 05/2014; 93(5):1263-9. · 1.54 Impact Factor
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    ABSTRACT: Aortic rupture in horses is a rare condition. Although it is relatively common in the Friesian breed, only limited histopathologic information is available. Twenty Friesian horses (1-10 years old) were diagnosed with aortic rupture by postmortem examination. Ruptured aortic walls were analyzed with histology and immunohistochemistry. Based on the histologic and immunohistochemical findings, these cases were divided into 3 groups: acute (n = 4, 20%), subacute (n = 8, 40%), and chronic (n = 8, 40%). Features common to samples from horses in all groups included accumulation of mucoid material; disorganization and fragmentation of the elastic laminae; aortic medial smooth muscle hypertrophy; and medial necrosis of varying degrees, ranging from mild and patchy in the acute cases to severe midzonal necrosis in the chronic cases. Inflammation, most likely secondary to medial necrosis, varied from predominantly neutrophilic infiltrates in the media and periadventitial tissue in the acute group to the presence of mainly hemosiderophages in the periadventitial tissue in the chronic group. Medial fibrosis with aberrant collagen morphology was seen in the subacute group and, more commonly, in the chronic group. Only minimal changes were seen in the aortic vasa vasorum. Smooth muscle hypertrophy and accumulation of mucoid material were not related to the age of the lesions. The findings of this study suggest that a connective tissue disorder affecting elastin or collagen in the aortic media is potentially the underlying cause of aortic rupture in Friesian horses.
    Veterinary Pathology 04/2014; · 2.04 Impact Factor
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    ABSTRACT: Necrotic enteritis in broiler chickens is associated with netB positive Clostridium perfringens type A strains. It is known that C. perfringens strains isolated from outbreaks of necrotic enteritis are more capable of secreting factors inhibiting growth of other C. perfringens strains than strains isolated from the gut of healthy chickens. This characteristic could lead to extensive and selective presence of a strain that contains the genetic make-up enabling to secrete toxins that cause gut lesions. This report describes the discovery, purification, characterization and recombinant expression of a novel bacteriocin, referred to as perfrin, produced by a necrotic enteritis-associated netB-positive C. perfringens strain. Perfrin is a 11.5 kDa C-terminal fragment of a 22.9 kDa protein and showed no sequence homology to any currently known bacteriocin. The 11.5 kDa fragment can be cloned into Escherichia coli, and expression yielded an active peptide. PCR detection of the gene showed its presence in 10 netB-positive C. perfringens strains of broiler origin, and not in other C. perfringens strains tested (isolated from broilers, cattle, sheep, pigs, and humans). Perfrin and NetB are not located on the same genetic element since NetB is plasmid-encoded and perfrin is not. The bacteriocin has bactericidal activity over a wide pH-range but is thermolabile and sensitive to proteolytic digestion (trypsin, proteinase K). C. perfringens bacteriocins, such as perfrin, can be considered as an additional factor involved in the pathogenesis of necrotic enteritis in broilers.
    Veterinary Research 04/2014; 45(1):40. · 3.38 Impact Factor
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    ABSTRACT: P-glycoprotein (P-gp) plays a major role as an efflux pump for endogenous and exogenous substrates at the blood-brain barrier and is localized in the brain at the apical side of capillary endothelial cells. Bovine spongiform encephalopathy (BSE) is marked primarily by the build-up of protease resistant misfolded prion protein (PrPres) in the brain. In the present study, the relationship between P-gp and BSE was investigated. An increase in the expression of vascular Pgp in the obex was found inclassical BSE, more prominent in the pre-clinical cases. This upregulation of P-gp in the early stages of the disease might be a protective regulatory mechanism to increase the clearance of the abnormal PrPres protein in an attempt to protect the brain from the accumulation of PrPres.
    International Journal of Development Research. 03/2014; 4(3):410-413.
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    ABSTRACT: Background Although the infection rate of Helicobacter suis is significantly lower than that of Helicobacter pylori, the H. suis infection is associated with a high rate of gastric mucosa-associated lymphoid tissue (MALT) lymphoma. In addition, in vitro cultivation of H. suis remains difficult, and some H. suis-infected patients show negative results on the urea breath test (UBT).Materials and Methods Female C57BL/6J mice were orally inoculated with mouse gastric mucosal homogenates containing H. suis strains TKY or SNTW101 isolated from a cynomolgus monkey or a patient suffering from nodular gastritis, respectively. The high-purity chromosomal DNA samples of H. suis strains TKY and SNTW101 were prepared from the infected mouse gastric mucosa. The SOLiD sequencing of two H. suis genomes enabled comparative genomics of 20 Helicobacter and 11 Campylobacter strains for the identification of the H. suis-specific nucleotide sequences.ResultsOral inoculation with mouse gastric mucosal homogenates containing H. suis strains TKY and SNTW101 induced gastric MALT lymphoma and the formation of gastric lymphoid follicles, respectively, in C57BL/6J mice. Two conserved nucleotide sequences among six H. suis strains were identified and were used to design diagnostic PCR primers for the detection of H. suis.Conclusions There was a strong association between the H. suis infection and gastric diseases in the C57BL/6 mouse model. PCR diagnosis using an H. suis-specific primer pair is a valuable method for detecting H. suis in gastric biopsy specimens.
    Helicobacter 03/2014; · 2.99 Impact Factor
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    ABSTRACT: Thyroid carcinoma is a common endocrine tumor in the dog. Local invasive growth frequently precludes surgical excision and, in up to 38% of dogs, the tumor has already metastasized by the time of diagnosis. Therefore, it is important to investigate new treatment modalities that may be useful for the large number of dogs with inoperable tumors or metastatic disease. To investigate the immunohistochemical expression of potential therapeutic targets in canine thyroid tumors. 74 dogs with thyroid neoplasia. Immunohistochemistry was performed for thyroglobulin, calcitonin, vascular endothelial growth factor (VEGF), p53, cycloxygenase-2 (cox-2), and P-glycoprotein (P-gp). Fifty-four (73%) tumors were classified as follicular cell thyroid carcinomas (FTCs) and 20 (27%) as medullary thyroid carcinomas (MTCs). Eighty percent of FTCs and all MTCs had a high percentage (76-100%) of neoplastic cells immunopositive for VEGF. Thirteen percent of FTCs and 50% of MTCs expressed cox-2. Seven percent of FTCs and 70% of MTCs expressed P-gp. No tumor was immunopositive for p53 expression. Expression of VEGF (P = .034), cox-2 (P = .013), and P-gp (P < .001) was significantly higher in MTCs compared to FTCs. VEGF is a potential therapeutic target in both FTC and MTC in dogs. Cox-2 and P-gp may be useful molecular targets in canine MTC.
    Journal of Veterinary Internal Medicine 02/2014; · 2.06 Impact Factor
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    ABSTRACT: The objective of the study was to investigate the effect of feed restriction on the intestinal ecosystem and on the pathogenesis of experimental necrotic enteritis in broiler chicks. To induce subclinical necrotic enteritis, an experimental challenge model using a specific diet formulation, Gumboro vaccination, oral inoculation of broilers with a 10-fold dose of attenuated anticoccidial vaccine and multiple oral inoculations with a specific strain of Clostridium perfringens, was adapted,. Two hundred and forty day-old Cobb 500 broilers were randomly allocated to groups feed restricted, challenged, both feed restricted and challenged, and a negative control. From each bird, the intestines, gizzard and liver were collected and scored for gross lesions at 21, 22, 23 and 24 days of age. The intestinal digesta was collected for pH and viscosity determination. One caecum from each bird was taken for microbiological analysis. The application of feed restriction in birds challenged with C. perfringens reduced the necrotic enteritis lesion score significantly (P ≤ 0.05) and feed restriction significantly reduced (P ≤ 0.05) pH in the small intestine, the viscosity of the jejunum digesta as well as the C. perfringens counts in the caeca compared to the control. In conclusion, feed restriction of broilers has a positive effect on the intestinal ecosystem and a significant protective effect against necrotic enteritis in the subclinical experimental model.
    Avian Pathology 02/2014; · 2.04 Impact Factor
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    ABSTRACT: Contamination of food and feed with mycotoxins is a worldwide problem. At present, acute mycotoxicosis caused by high doses is rare in humans and animals. Ingestion of low to moderate amounts of Fusarium mycotoxins is common and generally does not result in obvious intoxication. However, these low amounts may impair intestinal health, immune function and/or pathogen fitness, resulting in altered host pathogen interactions and thus a different outcome of infection. This review summarizes the current state of knowledge about the impact of Fusarium mycotoxin exposure on human and animal host susceptibility to infectious diseases. On the one hand, exposure to deoxynivalenol and other Fusarium mycotoxins generally exacerbates infections with parasites, bacteria and viruses across a wide range of animal host species. Well-known examples include coccidiosis in poultry, salmonellosis in pigs and mice, colibacillosis in pigs, necrotic enteritis in poultry, enteric septicemia of catfish, swine respiratory disease, aspergillosis in poultry and rabbits, reovirus infection in mice and Porcine Reproductive and Respiratory Syndrome Virus infection in pigs. However, on the other hand, T-2 toxin has been shown to markedly decrease the colonization capacity of Salmonella in the pig intestine. Although the impact of the exposure of humans to Fusarium toxins on infectious diseases is less well known, extrapolation from animal models suggests possible exacerbation of, for instance, colibacillosis and salmonellosis in humans, as well.
    Toxins 02/2014; 6(2):430-52. · 2.48 Impact Factor
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    ABSTRACT: Bovine enterotoxemia is a major cause of mortality in veal calves. Predominantly veal calves of beef cattle breeds are affected and losses due to enterotoxemia may account for up to 20% of total mortality. Clostridium perfringens type A is considered to be the causative agent. Recently, alpha toxin and perfringolysin O have been proposed to play an essential role in the development of disease. However, other potential virulence factors also may play a role in the pathogenesis of bovine enterotoxemia. The aim of this study was to evaluate whether strains originating from bovine enterotoxemia cases were superior in in vitro production of virulence factors (alpha toxin, perfringolysin O, mucinase, collagenase) that are potentially involved in enterotoxemia. To approach this, a collection of strains originating from enterotoxemia cases was compared to bovine strains isolated from healthy animals and to strains isolated from other animal species. Strains originating from bovine enterotoxemia cases produced variable levels of alpha toxin and perfringolysin O that were not significantly different from levels produced by strains isolated from healthy calves and other animal species. All tested strains exhibited similar mucinolytic activity independent of the isolation source. A high variability in collagenase activity between strains could be observed, and no higher collagenase levels were produced in vitro by strains isolated from enterotoxemia cases. Bovine enterotoxemia strains do not produce higher levels of alpha toxin, perfringolysin O, mucinase and collagenase, as compared to strains derived from healthy calves and other animal species in vitro.
    BMC Veterinary Research 01/2014; 10(1):32. · 1.74 Impact Factor
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    ABSTRACT: In humans, adipose tissue (AT) originating from different depots shows varying gene expression profiles. In horses, the risk of certain metabolic disorders may also be influenced by the impact of specific AT depots. Macrophage infiltration in human and rat AT is considered to be a source of inflammatory changes. In horses, this relationship has not been extensively studied yet. Reverse transcription quantitative real-time polymerase chain reaction (RT-qPCR), a useful method to evaluate differences in mRNA expression across different tissues, can be used to evaluate differences between equine AT depots. For a correct interpretation of the RT-qPCR results, expression data have to be normalized by the use of validated reference genes. The main objectives of this study were to compare mRNA expression of inflammation-related genes, as well as adipocyte morphology and number between different equine AT depots; and in addition, to investigate the presence of antigen presenting cells in equine AT and any potential relationship with adipokine mRNA expression. In this study, the mRNA expression of inflammation-related genes (leptin, chemokine ligand 5, interleukin 1beta, interleukin 6, interleukin 10, adiponectin, matrix metalloproteinase 2, and superoxide dismutase 2) and candidate reference gene stability was investigated in 8 different AT depots collected from the nuchal, abdominal (mesenteric, retroperitoneal, and peri-renal) and subcutaneous (tail head and loin) AT region. By using GeNorm analysis, HPRT1, RPL32, and GAPDH were found to be the most stable genes in equine AT. The mRNA expression of leptin, chemokine ligand 5, interleukin 10, interleukin 1beta, adiponectin, and matrix metalloproteinase 2 significantly differed across AT depots (P < 0.05). No significant AT depot effect was found for interleukin 6 and superoxide dismutase 2 (P > 0.05). Adipocyte area and number of antigen presenting cells per adipocyte significantly differed between AT depots (P < 0.05). Adipose tissue location was associated with differences in mRNA expression of inflammation-related genes. This depot-specific difference in mRNA expression suggests that the overall inflammatory status of horses could be partially determined by the relative proportion of the different AT depots.
    BMC Veterinary Research 12/2013; 9(1):240. · 1.74 Impact Factor
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    ABSTRACT: The aim of the study was to characterize isolates of Salmonella enterica serovar Enteritidis (S. Enteritidis) obtained from humans and layer farms in Belgium collected during 2000-2010. Three periods were compared, namely (i) before implementation of vaccination (2000-2004), (ii) during voluntary vaccination (2005-2006) and (iii) during implementation of the national control program (NCP) for Salmonella including mandatory vaccination against S. Enteritidis (2007-2010). The characteristics compared across time periods were distributions of phage type and multiple-locus variable number tandem-repeat assay (MLVA). While PT4 and PT21 were predominantly isolated in Belgium in layers and humans before 2007, a significant reduction of those PTs was observed in both populations in the period 2007-2010. The relative proportion of PT4b, PT21c and PT6c was found to have increased considerably in the layer population since 2007. In the human population, PT8, PT1 and the group of 'other' PTs were more frequently isolated compared to the previous periods. When comparing the proportion of the predominant MLVA types Q2 and U2, no significant difference was found between the layer and human population in the three periods and between periods within each category (layer and human). A significant difference in isolate distribution among MLVA clusters I and II was found between human and layer isolates recovered during Period 3 and in the human population between Period 1 and 3. Results suggest that the association between S. Enteritidis in layers and the occurrence of the pathogen in humans changed since implementation of the NCP in 2007.
    Zoonoses and Public Health 11/2013; · 2.09 Impact Factor
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    ABSTRACT: Clostridium perfringens type A has been shown to be the causative agent of a wide variety of enteric diseases in humans and animals, including bovine enterotoxemia. Enterotoxemia is a sudden death syndrome with necro hemorrhagic lesions in the small intestine, which mainly affects suckling calves and veal calves [1]. Predominantly veal calves of beef cattle breeds are affected, and losses due to enterotoxemia may be responsible for up to 20% of total mortality [2, 3]. Recently, alpha toxin has been proposed as an essential factor for induction of enterotoxemia in veal calves, which introduces the possibility to use it as a vaccine [4]. The use of only the main toxin instead of the whole arsenal of extracellular toxins and enzymes eliminates irrelevant or even immunosuppressive components and therefore may induce a stronger, protective immune response. In this study, we have compared a commercial multivalent vaccine with native alpha toxin, formalin inactivated alpha toxin and recombinant C-terminal domain of alpha toxin as vaccine candidates. The native and recombinant alpha toxin were capable of stimulating higher levels of immune responses compared to the formalin inactivated alpha toxin and the multivalent vaccine. In addition, the sera from calves immunized with the native and recombinant alpha toxin also showed higher inhibitory activity against the alpha toxin in a bioassay. These results suggest that the recombinant alpha toxin is a potential vaccine candidate against bovine enterotoxemia. 1. Muylaert A, Lebrun M, Duprez JN, Labrozzo S, Theys H, Taminiau B, Mainil J: Enterotoxaemia-like syndrome and Clostridium perfringens in veal calves. The Veterinary record 2010, 167(2):64-65. 2. Lebrun M, Mainil JG, Linden A: Cattle enterotoxaemia and Clostridium perfringens: description, diagnosis and prophylaxis. The Veterinary record 2010, 167(1):13-22. 3. Pardon B, De Bleecker K, Hostens M, Callens J, Dewulf J, Deprez P: Longitudinal study on morbidity and mortality in white veal calves in Belgium. BMC veterinary research 2012, 8:26. 4. Verherstraeten S, Goossens E, Valgaeren B, Pardon B, Timbermont L, Vermeulen K, Schauvliege S, Haesebrouck F, Ducatelle R, Deprez P et al: The synergistic necrohemorrhagic action of Clostridium perfringens perfringolysin and alpha toxin in the bovine intestine and against bovine endothelial cells. Veterinary research 2013, 44(1):45.
    Symposium on Gut Health in Production of Food Animals, Kansas City, Missouri; 11/2013
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    ABSTRACT: As adhesion and translocation through fish gut enterocytes of the pathogen Vibrio (Listonella) anguillarum are not well investigated, the effective cause of disease and mortality outbreaks in larval sea bass, Dicentrarchus labrax, suffering from vibriosis is unknown. We detected V. anguillarum within the gut of experimentally infected gnotobiotic sea bass larvae using transmission electron microscopy and immunogold labelling. Intact bacteria were observed in close contact with the apical brush border in the gut lumen. Enterocytes contained lysosomes positive for protein A‐gold particles suggesting intracellular elimination of bacterial fragments. Shed intestinal cells were regularly visualized in the gut lumen in late stages of exposure. Some of the luminal cells showed invagination and putative engulfment of bacterial structures by pseudopod‐like formations. The engulfed structures were positive for protein A‐colloidal gold indicating that these structures were V. anguillarum. Immunogold positive thread‐like structures secreted by V. anguillarum suggested the presence of outer membrane vesicles (MVs) hypothesizing that MVs are potent transporters of active virulence factors to sea bass gut cells suggestive for a substantial role in biofilm formation and pathogenesis. We put forward the hypothesis that MVs are important in the pathogenesis of V. anguillarum in sea bass larvae.
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    ABSTRACT: There is increased proportional mortality from Parkinson's disease amongst livestock farmers. The hypokinesia of Parkinson's disease has been linked to Helicobacter pylori. H. suis is the most common zoonotic helicobacter in man. To compare the frequency of H. suis, relative to H. pylori, in gastric biopsies of patients with idiopathic parkinsonism (IP) and controls from gastroenterology services. DNA extracts, archived at a Helicobacter Reference Laboratory, from IP patient and gastroenterology service biopsies were examined anonymously for H. suis, using species-specific RT-PCR. Relative risk of having H. suis in 60 IP patients compared with 256 controls was 10 times greater than that of having H. pylori. In patients with IP and controls, respectively, frequencies of H. suis were 27 (exact binomial 95% C.I. 15, 38) and 2 (0, 3)%, and of H. pylori, 28 (17, 40) and 16 (12, 21)%. Excess of H. suis in IP held when only the antral or corporal biopsy was considered. Of 16 IP patients with H. suis, 11 were from 19 with proven H. pylori eradication, 3 from 17 pre-H. pylori eradication, 2 from 24 H. pylori culture/PCR-negative. Frequency was different between groups (P = 0.001), greatest where H. pylori had been eradicated. Even without known exposure to anti-H. pylori therapy, H. suis was more frequent in IP patients (5/41) than in controls (1/155) (P = 0.002). Partial multilocus sequence typing confirmed that strains from IP patients (6) and control (1) differed from RT-PCR standard strain. Greater frequency of H. suis in idiopathic parkinsonism appears exaggerated following H. pylori eradication. Multilocus sequence testing comparison with porcine strains may clarify whether transmission is from pigs/porcine products or of human-adapted, H. suis-like, bacteria.
    Alimentary Pharmacology & Therapeutics 10/2013; 38(11-12):1347-1353. · 4.55 Impact Factor
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    ABSTRACT: Digital Dermatitis (DD) is a common disease of dairy cows, the pathogenesis of which is still not clear. This study examined some host responses associated with the typical lesions, in an attempt to further elucidate the pathogenesis of the disease. Twenty four samples representing the 5 different clinical stages of DD (M0-M4) were collected from slaughtered cattle for histopathological and immunological analyses. Significant increases in total epidermal thickness were found in M2, M3, and M4 when compared with M0 and M1. M3 samples, when compared with M0 and M1, were characterized by a significant increase in the thickness of the keratin layer. Counts of both eosinophils and neutrophils were at a maximum in the M2 stage and decreased in the M3 and M4 stage. A significant increase in IL8 expression was observed in the M2-M3 stages of the disease and immunohistochemical staining showed the source as keratinocytes, suggesting an important role for keratinocyte-derived IL8 in the pathogenesis of DD. Results of the present study point to a strong stimulation of the innate immune response at the level of the keratinocytes throughout most of the clinical stages, and a delayed response of the adaptive immune reaction.
    BMC Veterinary Research 10/2013; 9(1):193. · 1.74 Impact Factor
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    ABSTRACT: Helicobacter (H.) suis colonizes the stomach of the majority of pigs as well as a minority of humans worldwide. Infection causes chronic inflammation in the stomach of the host, however without an effective clearance of the bacteria. Currently, no information is available about possible mechanisms H. suis utilizes to interfere with the host immune response. This study describes the effect on various lymphocytes of the γ-glutamyl transpeptidase (GGT) from H. suis. Compared to whole cell lysate from wild-type H. suis, lysate from a H. suis ggt mutant strain showed a decrease of the capacity to inhibit Jurkat T cell proliferation. Incubation of Jurkat T cells with recombinantly expressed H. suis GGT resulted in an impaired proliferation, and cell death was shown to be involved. A similar but more pronounced inhibitory effect was also seen on primary murine CD4 + T cells, CD8 + T cells, and CD19 + B cells. Supplementation with known GGT substrates was able to modulate the observed effects. Glutamine restored normal proliferation of the cells, whereas supplementation with reduced glutathione strengthened the H. suis GGT-mediated inhibition of proliferation. H. suis GGT treatment abolished secretion of IL-4 and IL-17 by CD4 + T cells, without affecting secretion of IFN-γ. Finally, H. suis outer membrane vesicles (OMV) were identified as a possible delivery route of H. suis GGT to lymphocytes residing in the deeper mucosal layers. Thus far, this study is the first to report that the effects on lymphocytes of this enzyme, not only important for H. suis metabolism but also for that of other Helicobacter species, depend on the degradation of two specific substrates: glutamine and reduced glutatione. This will provide new insights into the pathogenic mechanisms of H. suis infection in particular and infection with gastric helicobacters in general. Citation: Zhang G, Ducatelle R, Pasmans F, D'Herde K, Huang L, et al. (2013) Effects of Helicobacter suis γ-Glutamyl Transpeptidase on Lymphocytes: Modulation by Glutamine and Glutathione Supplementation and Outer Membrane Vesicles as a Putative Delivery Route of the Enzyme. PLoS ONE 8(10): e77966. doi:10.1371/journal.pone.0077966
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    ABSTRACT: Consumption of contaminated poultry meat is an important cause of Salmonella infections in humans. Therefore, there is a need for control methods that protect broilers from day-of-hatch until slaughter age against infection with Salmonella. Colonization-inhibition, a concept in which a live Salmonella strain is orally administered to day-old chickens and protects against subsequent challenge, can potentially be used as control method. In this study, the safety and efficacy of a Salmonella Enteritidis ΔhilAssrAfliG strain as a colonization-inhibition strain for protection of broilers against Salmonella Enteritidis was evaluated. After administration of the Salmonella Enteritidis ΔhilAssrAfliG strain to day-old chickens, this strain could not be isolated from the gut, internal organs or faeces after 21 days of age. In addition, administration of this strain to one-day-old broiler chickens decreased faecal shedding and caecal and internal organ colonization of a Salmonella Enteritidis challenge strain administered one day later using a seeder bird model. To our knowledge, this is the first report of an attenuated Salmonella strain for which both the safety and efficacy has been shown in long-term experiments (until slaughter age) in broiler strain can potentially be used as a live colonization-inhibition strain for controlling Salmonella Enteritidis infections in broilers.
    Vaccine 09/2013; · 3.49 Impact Factor

Publication Stats

5k Citations
1,085.91 Total Impact Points

Institutions

  • 1981–2014
    • Ghent University
      • • Department of Pathology, Bacteriology and Avian Diseases
      • • Faculty of Veterinary Medicine
      • • Department of Pathology
      Gand, Flanders, Belgium
    • CSU Mentor
      • Department of Veterinary Pathology
      Long Beach, California, United States
  • 2013
    • Aristotle University of Thessaloniki
      • Faculty of Veterinary Medicine
      Thessaloníki, Kentriki Makedonia, Greece
  • 2011–2013
    • Institute for Agricultural and Fisheries Research
      • Technology and Food Science Unit
      Meirelbeke, Flanders, Belgium
    • Universitair Ziekenhuis Ghent
      Gand, Flanders, Belgium
  • 2010
    • Vlaams Ministerie van Mobiliteit en Openbare Werken
      Bruxelles, Brussels Capital Region, Belgium
  • 2009
    • University of Helsinki
      • Institute of Biotechnology
      Helsinki, Southern Finland Province, Finland
  • 2007–2009
    • University of Antwerp
      • • Faculteit Farmaceutische, Biomedische en Diergeneeskundige Wetenschappen
      • • Laboratory of Pathophysiology
      Antwerpen, VLG, Belgium
  • 2008
    • University of Liège
      • Faculté de Médecine Vétérinaire
      Liège, WAL, Belgium
  • 2004
    • University of California, Davis
      Davis, California, United States
  • 2001
    • Vrije Universiteit Brussel
      Bruxelles, Brussels Capital Region, Belgium
  • 1998–2001
    • Veterinary and Agrochemical Research Centre
      • Virology
      Bruxelles, Brussels Capital Region, Belgium