Showing papers by "An Martel published in 2013"
TL;DR: A unique chytrid fungus is isolated and characterized, Batrachochytrium salamandrivorans sp.
Abstract: The current biodiversity crisis encompasses a sixth mass extinction event affecting the entire class of amphibians. The infectious disease chytridiomycosis is considered one of the major drivers of global amphibian population decline and extinction and is thought to be caused by a single species of aquatic fungus, Batrachochytrium dendrobatidis. However, several amphibian population declines remain unexplained, among them a steep decrease in fire salamander populations (Salamandra salamandra) that has brought this species to the edge of local extinction. Here we isolated and characterized a unique chytrid fungus, Batrachochytrium salamandrivorans sp. nov., from this salamander population. This chytrid causes erosive skin disease and rapid mortality in experimentally infected fire salamanders and was present in skin lesions of salamanders found dead during the decline event. Together with the closely related B. dendrobatidis, this taxon forms a well-supported chytridiomycete clade, adapted to vertebrate hosts and highly pathogenic to amphibians. However, the lower thermal growth preference of B. salamandrivorans, compared with B. dendrobatidis, and resistance of midwife toads (Alytes obstetricans) to experimental infection with B. salamandrivorans suggest differential niche occupation of the two chytrid fungi.
522 citations
TL;DR: The described duplex real-time PCR can be used to detect DNA of B. dendrobatidis and B. salamandrivorans with highly reproducible and reliable results.
Abstract: Chytridiomycosis is a lethal fungal disease contributing to declines and extinctions of amphibian species worldwide. The currently used molecular screening tests for chytridiomycosis fail to detect the recently described species Batrachochytrium salamandrivorans. In this study, we present a duplex real-time PCR that allows the simultaneous detection of B. salamandrivorans and Batrachochytrium dendrobatidis. With B. dendrobatidis- and B. salamandrivorans-specific primers and probes, detection of the two pathogens in amphibian samples is possible, with a detection limit of 0.1 genomic equivalent of zoospores of both pathogens per PCR. The developed real-time PCR shows high degrees of specificity and sensitivity, high linear correlations (r2 > 0.995), and high amplification efficiencies (>94%) for B. dendrobatidis and B. salamandrivorans. In conclusion, the described duplex real-time PCR can be used to detect DNA of B. dendrobatidis and B. salamandrivorans with highly reproducible and reliable results.
140 citations
TL;DR: A sharp decline in numbers has been observed since 2010, but it is unable to attribute this to any known cause of amphibian decline, such as chytridiomycosis, ranavirus or habitat degradation.
Abstract: In the Netherlands, the fire salamander (Salamandra salamandra) is at the edge of its geographic range and is restricted to three small populations in the extreme south of the country. Despite the species being listed as 'Endangered' on the national Red List, the situation was considered to be stable. However, from 2008 onwards dead individuals were seen on more than one occasion. A sharp decline in numbers has been observed since 2010 (96%; P< 0.01), but we were unable to attribute this to any known cause of amphibian decline, such as chytridiomycosis, ranavirus or habitat degradation. The present work describes this enigmatic decline, and we discuss these results in the context of possible causes.
84 citations
TL;DR: Fungal release into the extra-protozoan environment by exocytosis of conidia or by germination was observed with light and transmission electron microscopy, which suggests that Aspergillus fumigatus virulence mechanisms to evade macrophage killing may be acquired by co-evolutionary interactions among A. fumicatus and environmental amoebae.
Abstract: Aspergillus fumigatus and free-living amoebae are common inhabitants of soil. Mechanisms of A.fumigatus to circumvent the amoeba's digestion may facilitate overcoming the vertebrate macrophage defence mechanisms. We performed co-culture experiments using A.fumigatus conidia and the amoeba Acanthamoeba castellanii. Approximately 25% of the amoebae ingested A. fumigatus conidia after 1 h of contact. During intra-amoebal passage, part of the ingested conidia was able to escape the food vacuole and to germinate inside the cytoplasm of A.castellanii. Fungal release into the extra-protozoan environment by exocytosis of conidia or by germination was observed with light and transmission electron microscopy. These processes resulted in structural changes in A.castellanii, leading to amoebal permeabilization without cell lysis. In conclusion, A.castellanii internalizes A.fumigatus conidia, resulting in fungal intracellular germination and subsequent amoebal death. As such, this interaction highly resembles that of A.fumigatus with mammalian and avian macrophages. This suggests that A.fumigatus virulence mechanisms to evade macrophage killing may be acquired by co-evolutionary interactions among A.fumigatus and environmental amoebae.
48 citations
TL;DR: The absence of Bd in Speleomantes combined with resistance to experimental chytridiomycosis and highly efficient skin defenses indicate that the genus Spelemantes is a taxon unlikely to decline due to Bd.
Abstract: North America and the neotropics harbor nearly all species of plethodontid salamanders. In contrast, this family of caudate amphibians is represented in Europe and Asia by two genera, Speleomantes and Karsenia, which are confined to small geographic ranges. Compared to neotropical and North American plethodontids, mortality attributed to chytridiomycosis caused by Batrachochytrium dendrobatidis (Bd) has not been reported for European plethodontids, despite the established presence of Bd in their geographic distribution. We determined the extent to which Bd is present in populations of all eight species of European Speleomantes and show that Bd was undetectable in 921 skin swabs. We then compared the susceptibility of one of these species, Speleomantes strinatii, to experimental infection with a highly virulent isolate of Bd (BdGPL), and compared this to the susceptible species Alytes muletensis. Whereas the inoculated A. muletensis developed increasing Bd-loads over a 4-week period, none of five exposed S. strinatii were colonized by Bd beyond 2 weeks post inoculation. Finally, we determined the extent to which skin secretions of Speleomantes species are capable of killing Bd. Skin secretions of seven Speleomantes species showed pronounced killing activity against Bd over 24 hours. In conclusion, the absence of Bd in Speleomantes combined with resistance to experimental chytridiomycosis and highly efficient skin defenses indicate that the genus Speleomantes is a taxon unlikely to decline due to Bd.
40 citations
TL;DR: The results of this study show that drug metabolizing enzymes and drug transporter mechanisms can be influenced due to prolonged exposure to relevant doses of T-2.
36 citations
TL;DR: A novel species of Chlamydiales with a prevalence of 71% in exotic invasive bullfrog tadpoles from an introduced population in the Netherlands is identified and sequence of a 1474 bp 16S rRNA gene fragment showed that the novel taxon forms a well-defined clade with 'Candidatus Amphibiichlamydia salamandrae' within the ChlamYDiaceae family.
Abstract: Summary Knowledge concerning microbial infectious diseases in the current amphibian crisis is rudimentary and largely limited to ranavirosis and chytridiomycosis. The family Chlamydiaceae is gaining attention as a common cause of disease in amphibians and may harbour new and emerging amphibian pathogens. We identified a novel species of Chlamydiales (Candidatus Amphibiichlamydia ranarum) with a prevalence of 71% in exotic invasive bullfrog tadpoles (Lithobates catesbeianus) from an introduced population in the Netherlands. The sequence of a 1474 bp 16S rRNA gene fragment showed that the novel taxon forms a well-defined clade with ‘Candidatus Amphibiichlamydia salamandrae’ within the Chlamydiaceae family. Although none of the tadpoles examined showed signs of clinical disease, urgent evaluation of its pathogenic potential for native amphibian species is required.
25 citations
TL;DR: The in vitro results of the present study demonstrate the potential of EO components as antimicrobials against poultry Brachyspira isolates, including isolates with acquired resistance for classic antimicrobial drugs.
24 citations
TL;DR: Immunohistochemically, CPB was detected at microvascular endothelial cells in intestinal villi during early and advanced stages of lesions induced by C. perfringens type C. enteritis in pigs, suggesting that CPB-induced endothelial damage plays an important role in the early stages of the disease.
Abstract: Beta toxin (CPB) is known to be an essential virulence factor in the development of lesions of Clostridium perfringens type C enteritis in different animal species. Its target cells and exact mechanism of toxicity have not yet been clearly defined. Here, we evaluate the suitability of a neonatal piglet jejunal loop model to investigate early lesions of C. perfringens type C enteritis. Immunohistochemically, CPB was detected at microvascular endothelial cells in intestinal villi during early and advanced stages of lesions induced by C. perfringens type C. This was first associated with capillary dilatation and subsequently with widespread hemorrhage in affected intestinal segments. CPB was, however, not demonstrated on intestinal epithelial cells. This indicates a tropism of CPB toward endothelial cells and suggests that CPB-induced endothelial damage plays an important role in the early stages of C. perfringens type C enteritis in pigs.
22 citations
01 Jan 2013
TL;DR: In this article, a broth microdilution method was used to determine the antimicrobial susceptibility of 20 Brachyspira intermedia field isolates from laying hen flocks to components of essential oils (EO).
Abstract: Cecal enteritis due to Brachyspira infections tends to be chronic in laying hens. Limited availability of antimicrobial drugs for use in laying hens emphasizes the need for alternative control measures. A broth microdilution method was used to determine the antimicrobial susceptibility of 20 Brachyspira intermedia field isolates from laying hen flocks to components of essential oils (EO). Minimal inhibitory concentration (MIC) distributions, obtained for eight EO components, were all monomodal. Cinnamaldehyde had the lowest MIC values (40-80 mg/l), followed by nerolidol, capsaicin, carvacrol and thymol (80-320 mg/l), eugenol (160-640 mg/l) and linalool (320-1280 mg/l). The MIC ranges of piperine were mostly above the test-range of 1280 mg/l. In an in vivo experiment, coated cinnamaldehyde was supplemented to the feed of rearing pullets. A completely randomized experimental design with 4 treatments and 3 replicates each (replicate = group of 7 one-day-old birds) was applied. The negative and positive control birds received a conventional feed during the whole trial. The positive control group was orally inoculated on 3 consecutive days (day 22, 23 and 24) with 1 ml 1.0 x 108 cfu/ml of a B. intermedia field isolate. Two treatment groups (preventive and curative), identically inoculated, were fed the coated cinnamaldehyde supplemented feed (final cinnamaldehyde concentration in the feed of 500 ppm), the preventive group from day 1 and the curative from day 25. On day 32, ceca were collected for bacteriologic B. intermedia enumeration. The number of Brachyspirapositive birds and the mean enumeration of Brachyspira cells was decreased (P < 0.05) in the curative treated group versus the positive control group. The in vitro results of the present study demonstrate the potential of EO components as antimicrobials against poultry Brachyspira isolates, including isolates with acquired resistance for classic antimicrobial drugs. Reduction of Brachyspira colonization in young pullets was obtained, on a curative way, in an in vivo study using feed supplemented with coated cinnamaldehyde. Further studies are necessary to investigate the mode of action of the coated cinnamaldehyde in reducing Brachyspira colonization of the ceca.
21 citations
TL;DR: A novel approach combining the DNA intercalating dye ethidium monoazide and real-time PCR is presented that allows quantification of viable B. dendrobatidis cells without the need for culturing and was applied to assess the antifungal activity of the veterinary antiseptic F10(®) Antiseptic Solution.
TL;DR: There was no effect between fed and fasted turkeys for both the pharmacokinetics and the clinical outcome in an infection model, and it can be advised that the photoperiod should be <20 h to have sufficient drug intake.
Abstract: In poultry rearing, medicated drinking water is a commonly used administration route, but drug uptake can be affected by many factors. In this study, the influence of two important parameters, the photoperiod and feeding schemes, on florfenicol uptake in turkeys was tested. First, the uptake was determined as the pharmacokinetic/pharmacodynamic profile of florfenicol; and second, we evaluated the clinical efficacy of florfenicol against Ornithobacterium rhinotracheale. Both experiments were conducted during a 5-day treatment of 30 mg/kg body weight florfenicol administered via drinking water and considering different photoperiods and feeding schemes (group 20/4L: photoperiod of 20 h, fed ad libitum; group 16/8L: photoperiod of 16 h, fed ad libitum; group 16/8R: photoperiod of 16 h, fed ad libitum but feed was withdrawn during the dark period and replaced 1 h after lighting). On day 1 of treatment, all groups showed plasma concentrations above the minimum inhibitory concentration (both MIC50 and MIC90, 1 mg/l) of 37.7%, 63.5% and 53.1% of a 24-h interval for 20/4L, 16/8L and 16/8R, respectively. Only in the 16/8L and 16/8R groups was the MIC also exceeded on day 5 (47.9% and 21.5% of a 24-h interval, respectively). In all groups, a clinical improvement could be noticed, resulting in reduction of the clinical score. However, only the 16/8L and 16/8R groups showed significant differences from the control group. The results demonstrated an important influence of the photoperiod on the pharmacokinetics of florfenicol as well as the clinical outcome in an infection model. It can be advised that the photoperiod should be <20 h to have sufficient drug intake. Nevertheless, there was no effect between fed and fasted turkeys for both the pharmacokinetics and the clinical outcome.
TL;DR: A limited role of bullfrogs as carrier of these pathogens is suggested, suggesting their role as primary reservoirs for B. dendrobatidis transmission to native amphibian communities.
Abstract: Exotic invasive bullfrogs (Lithobates catesbeianus) are considered to exert a considerable negative impact on native amphibian communities. This can be due to competition and predation, but they are also a notorious source of the infectious diseases chytridiomycosis and ranavirosis, affecting amphibian populations globally. Little is known regarding their carriage of other microbial agents that might be transferred to humans or other animals. In this study we determined the occurrence of the amphibian pathogens Ranavirus and Batrachochytrium dendrobatidis and of the zoonotic agents Coxiella burnetii, Neospora caninum, Leptospira sp., Toxoplasma gondii, Mycoplasma sp., Campylobacter sp., Salmonella sp. and extended-spectrum beta-lactamase producing Escherichia coli in 164 bullfrogs from three populations in Belgium and The Netherlands. Although B. dendrobatidis was present at a high prevalence of 63%, mean infection loads were low with an average of 10.9 genomic equivalents (SD 35.5), confirming the role of bullfrogs as B. dendrobatidis carriers, but questioning their role as primary reservoirs for B. dendrobatidis transmission to native amphibian communities. All tested samples were negative for the other infectious agents examined. These results suggest a limited role of bullfrogs as carrier of these pathogens.
TL;DR: T-2 impaired the antifungal activities of chicken macrophages against A. fumigatus conidia, but might stimulate immune response by upregulating the expression of pro-inflammatory cytokines, chemokines and T-helper 1 cytokines.
Abstract: Aspergillosis is the most common fungal disease of the avian respiratory tract and is caused primarily by Aspergillus fumigatus. The respiratory macrophages provide important defence against aspergillosis. T-2 toxin (T-2), a trichothecene mycotoxin produced by Fusarium spp. in improperly stored agricultural products, has immunomodulatory effects. We studied the impact of T-2 on the antifungal response of the chicken macrophage cell line HD-11 against A. fumigatus infection. The macrophages were first exposed to 0.5 to 10 ng/ml T-2 for 24 h, and then their viability, antifungal activity, and cytokine expression in response to A. fumigatus conidial infection were determined. The viability of macrophages decreased when exposed to T-2 at concentrations higher than 1 ng/ml. One hour after conidial infection, phagocytosed conidia were observed in 30% of the non-T-2-exposed macrophages, but in only 5% of the macrophages exposed to 5 ng/ml T-2. Seven hours after infection, 24% of the conidia associated with non-T-2-exposed macrophages germinated, in contrast to 75% of those with macrophages exposed to 5 ng/ml T-2. A. fumigatus infection induced upregulation of interleukin (IL)-1β, CXCLi1, CXCLi2 and IL-12β, and downregulation of transforming growth factor-β4 in macrophages. Exposure of A. fumigatus-infected macrophages to T-2 at 1 to 5 ng/ml further upregulated the expression of IL-1β, IL-6, CCLi2, CXCLi1, CXCLi2, IL-18 (at 1 and 2 ng/ml) and IL-12β, and further downregulated that of transforming growth factor-β4 (at 5 ng/ml). In conclusion, T-2 impaired the antifungal activities of chicken macrophages against A. fumigatus conidia, but might stimulate immune response by upregulating the expression of pro-inflammatory cytokines, chemokines and T-helper 1 cytokines.
TL;DR: This study was performed to evaluate the possible health risks of mycotoxin-contaminated feed for cockatiels and found zearalenone was the most prevalent mycotoxins.
Abstract: Mycotoxins are toxic secondary metabolites of fungi. Animal feeds can be easily infected by fungi during production and storage, resulting in mycotoxin contamination. This study was performed to evaluate the possible health risks of mycotoxin-contaminated feed for cockatiels. The occurrence of mycotoxins in commercial parrot feeds (5 seed mixes and 5 pelleted feeds) was investigated by liquid chromatography tandem mass spectrometry. The following 12 mycotoxins were detected: zearalenone, deoxynivalenol, 3-acetyldeoxynivalenol, 15-acetyldeoxynivalenol, fusarenon X, aflatoxin B1, sterigmatocystin, alternariol, alternariol methylether, fumonisin B1, fumonisin B3, and ochratoxin A. Zearalenone was the most prevalent. Pathological effects after 21 days feeding mycotoxin-contaminated diets were examined in an in vivo trial with 3 groups of 5 cockatiels: group 1 (control) was fed a non-contaminated pelleted feed; group 2 was fed a pelleted feed containing zearalenone, deoxynivalenol, 15-acetyldeoxynivalenol, and...
TL;DR: The rarity of these animals, their pronounced susceptibility to chytridiomycosis, an apparently suitable environmental context and increasing likelihood of the pathogen being introduced, together suggest the need of urgent measures to avoid future scenarios of extinction as witnessed in Central America and Australia.
Abstract: Until now, Asian amphibians appear to have largely escaped declines driven by chytridiomycosis. Vietnamese salamanders that belong to the genus Tylototriton are rare and have a patchy distribution in mountainous areas, falling within the proposed environmental envelope of chytrid infections, surrounded by Batrachochytrium dendrobatidis infected regions. If these salamanders are susceptible to chytridiomycosis, then their populations could be highly vulnerable after the introduction of B. dendrobatidis. Examination for the presence of the chytrid fungus in skin swabs from 19 Tylototriton asperrimus and 104 Tylototriton vietnamensis by using quantitative polymerase chain reaction was performed. Susceptibility of T. asperrimus to experimental infection by using the global panzootic lineage (BdGPL) strain of B. dendrobatidis was examined. The fungus was absent in all samples from all wild salamanders examined. Inoculation with the BdGPL strain resulted in mortality of all five inoculated salamanders within 3 weeks after inoculation with infected animals that manifested severe orthokeratotic hyperkeratosis, epidermal hyperplasia, and spongiosis. Although infection by B. dendrobatidis currently appears absent in Vietnamese Tylototriton populations, the rarity of these animals, their pronounced susceptibility to chytridiomycosis, an apparently suitable environmental context and increasing likelihood of the pathogen being introduced, together suggest the need of urgent measures to avoid future scenarios of extinction as witnessed in Central America and Australia.
TL;DR: A review focuses on the increasing importance of methicillin resistant staphylococci and broad-spectrum β-lactamase-producing Enterobacteriaceae in horses and diagnostic protocols that optimize accurate identification of these bacteria from both clinical samples and samples obtained from putative carrier animals.
01 Jan 2013
TL;DR: It is shown that feeding DON contaminated feed in concentrations below the European guidance contamination level to broilers is a predisposing factor for the development of necrotic enteritis and an altered barrier function after exposure to DON is indicated.
Abstract: Book p. 9-10 M26 Deoxynivalenol predisposes for necrotic enteritis by affecting the intestinal barrier in broilers Gunther Antonissen 1,2 , Filip Van Immerseel 1 , Frank Pasmans 1 , Richard Ducatelle 1 , Freddy Haesebrouck 1 , Leen Timbermont 1 , Marc Verlinden 1 , Geert Janssens 3 , Mia Eeckhout 4 , Sarah De Saeger 5 , Pascal Boeckx 6 , Evelyne Delezie 7 , Sabine Hessenberger 8 , An Martel 1 , Siska Croubels 2 1) Department of Pathology, Bacteriology and Poultry Diseases, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium 2) Department of Pharmacology, Toxicology and Biochemistry, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium 3) Department of Nutrition, Genetics, Breeding and Ethology, Faculty of Veterinary Medicine, Ghent University, Heidestraat 19, 9820 Merelbeke, Belgium 4) Department of Food Science and Technology, Faculty of Biosciences and Landscape Architecture, Ghent University, Schoonmeerstraat 52, 9000 Ghent, Belgium 5) Department of Bio-analysis, Faculty of Pharmaceutical Sciences, Ghent University, Harelbekestraat 72, 9000 Ghent, Belgium 6) Department of Applied analytical and physical chemistry, Faculty of Bioscience Engineering, Coupure Links 653, 9000 Ghent, Belgium 7) Institute for Agricultural and Fisheries Research (ILVO), Animal Sciences Unit, Scheldeweg 68, 9090 Melle, Belgium 8) Biomin Research Center, Technopark 1, 3430 Tulln, Austria E-mail: Gunther.Antonissen@UGent.be Clostridium perfringens induced subclinical necrotic enteritis (NE) and mycotoxins both cause important economic losses in the broiler industry. The Fusarium mycotoxin deoxynivalenol (DON) is a common feed contaminant that can affect the intestinal epithelial barrier function, and may as such increase the availability of free amino acids in the intestine. This can promote the massive intestinal proliferation of C. perfringens. The goal of this study was to evaluate and explain the predisposing effect of DON on NE. Therefore, an in vivo infection trial mimicking subclinical NE was conducted, comparing intestinal NE lesions in broilers after feeding DON at a contamination level below the European maximum guidance level of 5000 μg/kg feed, with broilers receiving non-contaminated feed. Subsequently, total and fractional nitrogen analyses were performed on the intestinal content to investigate the total protein concentration, and differentiate in proteins of animal, vegetable and bacterial origin. Furthermore, the nitrogen isotope ratio of intestinal content, intestines and diet was measured. An ex vivo Ussing chamber experiment was also conducted to assess the effect of DON on the barrier function of intestinal mucosa of broilers. Finally, the influence of different concentrations of DON on the growth of 8 different C. perfringens strains was tested in vitro by a well diffusion growth inhibition test and by assessment of the growth curve measuring the optical density of the C. perfringens culture. Significantly more chickens showed NE lesions in the in vivo study when their diet was contaminated with DON. The fractional nitrogen analyses showed a relative increase in protein amount of animal origin in the intestinal content. In the Ussing chamber experiments, the duodenal tissue resistance (Rt or TEER) was significantly lower in chickens who received DON contaminated feed. This indicates an altered barrier function after exposure to DON. DON did not have an effect on the in vitro growth of C. perfringens strains. In conclusion it is shown that feeding DON contaminated feed in concentrations below the maximum European guidance contamination level to broilers is a predisposing factor for the development of NE due to its effect on the intestinal barrier function.
TL;DR: The Apennine Yellow-bellied toad Bombina variegata pachypus, a small anuran endemic to peninsular Italy, has been declining throughout its range over the last 30 years, and mortality by chytridiomycosis was first reported for the species in 2004.
Abstract: The Apennine Yellow-bellied toad Bombina variegata pachypus , a small anuran endemic to peninsular Italy, has been declining throughout its range over the last 30 years. Although mortality by chytridiomycosis, caused by the fungus Batrachochytrium dendrobatidis , was first reported for the species in 2004, its role in the decline has not yet been assessed. Between 2011 and 2012 we sampled eight populations of B. v. pachypus in Liguria, northern Italy, swabbing 86 and 143 individuals respectively, corresponding to between 24 and 80% of the estimated individuals within each population. We did not detect chytrid in any the samples collected. For the three largest populations in the region, we can rule out infections of prevalence greater than 10% with at least 98% confidence. Research at a larger scale is urgently needed to clarify the role of B. dendrobatidis in the decline of this and other amphibians in Italy.
01 Jan 2013
01 Jan 2013
TL;DR: This dissertation aims at demonstrating the efforts towards in-situ applicability of EMMARM, as to provide real-time information about the response of the immune system to EMTs.
Abstract: 1Department of Pathology, Bacteriology and Poultry Diseases, 2Department of Pharmacology, Toxicology and Biochemistry, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, 3Department of Food Science and Technology, Faculty of Biosciences and Landscape Architecture, Ghent University, Valentin Vaerwyckweg 1, 9000 Ghent, 4Department of Bio-analysis, Faculty of Pharmaceutical Sciences, Ghent University, Harelbekestraat 72, 9000 Ghent, 5Institute for Agricultural and Fisheries Research (ILVO), Animal Sciences Unit, Scheldeweg 68, 9090 Melle, Belgium, 6Biomin Research Center, Technopark 1, 3430 Tulln, Austria E-mail: Gunther.Antonissen@UGent.be
01 Jan 2013
TL;DR: This dissertation aims to provide a history of poultry diseases in Belgium from 1989 to 2002, a period chosen in order to explore its roots as well as specific cases up to and including the year of bird flu of 1991.
Abstract: 1) Department of Pathology, Bacteriology and Poultry Diseases, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium 2) Department of Pharmacology, Toxicology and Biochemistry, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium 3) Department of Food Science and Technology, Faculty of Biosciences and Landscape Architecture, Ghent University, Valentin Vaerwyckweg 1, 9000 Ghent, Belgium 4) Department of Bio-analysis, Faculty of Pharmaceutical Sciences, Ghent University, Harelbekestraat 72, 9000 Ghent, Belgium 5) Institute for Agricultural and Fisheries Research (ILVO) Animal Sciences Unit, Scheldeweg 68, 9090 Melle, Belgium 6) Biomin Research Center, Technopark 1, 3430 Tulln, Austria E-mail: Gunther.Antonissen@UGent.be
TL;DR: The results provide a solid basis for the assumption that the use of microchip transponders does not result in negative behavioral or physical effects and that they are safe to use in juvenile Hermann's tortoises, allowing at least mid-term identification of tagged individuals.
Abstract: International conventions dictate reliable identification of various reptile species that are subject to intensive trade targeting and habitat destruction. As a rule, tortoises with a minimal plastron length of 100 mm are fitted with a microchip transponder. The development of new generations of transponders, however, may offer the possibility to identify smaller individuals. This study evaluated the use of microchip transponders in juvenile Hermann's tortoises, Testudo hermanni, by using two groups of 30 captive-bred tortoises. Microchip transponders were implanted in the first group of tortoises, and the second group served as a control group. During a 10 month observation period, including 2 months of hibernation, both groups were evaluated for short- as well as mid-term effects of microchip implantation, and readability of the microchips was checked twice a week. Body weight and plastron length were determined twice a week to compare growth and weight curves between both groups. Radiographs w...
01 Jan 2013
TL;DR: This dissertation aims to provide a history of poultry diseases in Belgium from 1989 to 2002, a period chosen in order to explore its roots as well as specific cases up to and including the 1970s.
Abstract: 1Department of Pathology, Bacteriology and Poultry Diseases, 2Department of Pharmacology, Toxicology and Biochemistry, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, 3Department of Food Science and Technology, Faculty of Biosciences and Landscape Architecture, Ghent University, Valentin Vaerwyckweg 1, 9000 Gent, 4Department of Bio-analysis, Faculty of Pharmaceutical Sciences, Ghent University, Harelbekestraat 72, 9000 Gent, Belgium, 5Biomin Research Center, Technopark 1, 3430 Tulln, Austria E-mail: Gunther.Antonissen@UGent.be
01 Jan 2013
TL;DR: The aim of this study was to describe the comparative pharmacokinetics of carboplatin in chickens, ducks, ducks), pigeons, pigeons and parakeets and show a two compartimental model with a significant larger peripheral compartment in chickens than in ducks and pigeons.
Abstract: The use of chemotherapy in the treatment of avian neoplasia is largely empirical, and poorly documented. Several chemotherapeutics that are frequently used in canine and feline oncology, have been used in a small number of avian cases with encouraging results. Most of these agents were administered to birds based on mammalian dose rates, because pharmacokinetic data in birds are lacking. Important pharmacokinetic differences, however, may exist between birds and mammalians, as well as between and within avian orders. The aim of this study was to describe the comparative pharmacokinetics of carboplatin in chickens (Gallus gallus domesticus), ducks (Anas platyrhynchos domesticus), pigeons (Columba livia) and parakeets (Melopsittacus undulates). Respectively 7 chickens, ducks and pigeons and 28 parakeets of one year old were used. Under general inhalation anesthesia carboplatin was administrated intravenously over 3 minutes at a dose of 5mg/kg BW. Blood was withdrawn at several intervals after the start of the infusion until 24h. Plasma carboplatin concentration were determined using liquid chromatography – mass spectrometry (LC-MS/MS). Pharmacokinetic parameters like area under plasma concentration versus time curve (AUC), volume of central and peripheral compartment, distribution and elimination half-life, and systemic clearance were determined. Results showed a two compartimental model with a significant larger peripheral compartment in chickens than in ducks and pigeons (P=0.002). The systemic clearance was significant higher in pigeons than in chickens and ducks (P<0.001). The elimination half-life was significant longer in chickens than in ducks and pigeons (P=0.006). Carboplatin was eliminated slower in chickens compared to ducks and
01 Jan 2013
TL;DR: Antonissen et al. as mentioned in this paper presented an overview of the departments of Pathology, Bacteriology and Poultry Diseases, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium.
Abstract: 1) Department of Pathology, Bacteriology and Poultry Diseases, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium 2) Department of Pharmacology, Toxicology and Biochemistry, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium 3) Department of Nutrition, Genetics, Breeding and Ethology, Faculty of Veterinary Medicine, Ghent University, Heidestraat 19, 9820 Merelbeke, Belgium 4) Department of Food Science and Technology, Faculty of Biosciences and Landscape Architecture, Ghent University, Valentin Vaerwyckweg 1, 9000 Ghent, Belgium 5) Department of Bio-analysis, Faculty of Pharmaceutical Sciences, Ghent University, Harelbekestraat 72, 9000 Ghent, Belgium 6) Institute for Agricultural and Fisheries Research (ILVO), Animal Sciences Unit, Scheldeweg 68, 9090 Melle, Belgium 7) Biomin Research Center, Technopark 1, 3430 Tulln, Austria E-mail: Gunther.Antonissen@UGent.be
01 Jan 2013
TL;DR: It seems like wild crows and geese do not play an important role in the spread of M. gallisepticum in Belgium, and further investigation in other wild birds is ongoing.
Abstract: Mycoplasma gallisepticum is the causative agent of chronic respiratory disease (CRD) in chickens. CRD is characterized by coughing, nasal discharge, sinusitis and severe lesions on the air sacs. Economic losses, due to a decrease in weight gain and egg production, are significant. Moreover, breeder flocks that are infected with M. gallisepticum have to be culled. Mycoplasma species are host restricted but infections with M. gallisepticum, which occur mostly in chickens, also have been detected in other bird species (reservoirs) such as pheasants, partridges, peacocks, ducks, wild turkeys, and house finches. The aim of this study was to investigate whether there were other reservoirs for M. gallisepticum in wildlife. Therefor we analyzed serum samples of wild crows and geese for the presence of antibodies against M. gallisepticum.
In 2012, blood samples of wild geese were collected in Belgium. Samples from Canadian geese (Branta canadensis) and Greylag geese (Anser anser) were tested. Samples from carrion crows (Corvus corone) were also collected in 2012. We obtained a total of 192 blood samples of acceptable quality to analyze the presence of antibodies against M. gallisepticum. Ninety-six samples were from crows and 96 were from geese. Antibodies were detected using a Blocking Enzyme Immunosorbent Assay (Svanovir® MG-Ab). Results were read using a photometer at 450 nm. All samples of both wild crows and geese were negative.
In this study, it seems like wild crows and geese do not play an important role in the spread of M. gallisepticum in Belgium. However, further investigation in other wild birds is ongoing.
Acks: T. Michiels is supported by the Federal Public Service of Health, Food Chain Safety and Environment (RCO-6752 MYCOPLASMA). The study was funded by the Federal Agency for the Safety of the Food Chain. The authors thank Didier Vangeluwe (Belgian Ringing Centre, Royal Belgian Institute for Natural Sciences, Belgium) for providing the samples.
01 Jan 2013
01 Jan 2013
TL;DR: Antonissen et al. as discussed by the authors presented an 8-year-old female cockatiel (Nymphicus hollandicus) with an ulcerative nodular lesion of approximately 4 cm3 ventromedial on the wing.
Abstract: An 8-year-old female cockatiel (Nymphicus hollandicus) was presented with anorexia, lethargy, a mass beneath the wing and discoloration of the feathers. On physical exam the bird had an ulcerative nodular lesion of approximately 4 cm3 ventromedial on the wing. Lateral and ventrodorsal radiographs revealed hepatomegaly but no signs of metastasis. After controlling the infection (enrofloxacine, 20 mg/kg BW, bid for 7 days), surgical excision of the tumor was performed. After histopathological evaluation and bacterial culture, the lesion was typed as an integumentary squamous cell carcinoma with bacterial contamination (Corynebacterium sp). Four weeks postoperative the tumor had recurred (volume 0.7 cm3). The bird was treated with intratumoral carboplatin (1.5 mg/cm3) administration once a week. Because of further tumor progression after the second administration of carboplatin, resection of the mass was performed before the next infiltration. However, the bird died during anesthesia. Despite increase in tumor size, histopathological and immunohistochemical evaluation showed degeneration of the tumor with intercellular edema and vacuolization of the tumorcells, presumably resulting from carboplatin administration. Intratumoral administration of carboplatin should be considered as a treatment option in birds with integumentary squamous cell carcinoma. AUTHOR ADDRESS: G. Antonissen, DVM Department of Pathology, Bacteriology and Poultry Diseases and Department of Pharmacology, Toxicology and Biochemistry Faculty of Veterinary Medicine Ghent University, Salisburylaan 133 9820 Merelbeke Belgium e-mail: Gunther.Antonissen@UGent.be