151
|
Hellebuyck T, Van Caelenberg A, Antonissen G, Haesendonck R, Martel A. Aviair bornavirus en kliermaagdilatatiesyndroom bij psittaciformen. VLAAMS DIERGEN TIJDS 2015. [DOI: 10.21825/vdt.v84i5.16591] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Aviair bornavirus (ABV) is het primaire etiologische agens dat het kliermaagdilatatiesyndroom (KDS) veroorzaakt bij psittaciformen. In tegenstelling tot wat oorspronkelijk over KDS verondersteld werd, blijkt ABV-infectie algemeen voor te komen bij psittaciformen en niet steeds aanleiding te geven tot klinische ziekte. In dit artikel wordt een overzicht gegeven van de huidige kennis van ABV. De diagnose, behandeling en het onder controle houden van KDS bij psittaciformen worden beschreven. Het stellen van een ante-mortemdiagnose van ABV als oorzaak van KDS vormt een uitdaging. Voornamelijk het correleren van de ABV-status aan het waargenomen klinische beeld is niet steeds vanzelfsprekend. De nood aan betere diagnostische methoden met een hoge sensitiviteit en specificiteit om ABV-infectie te detecteren, dringt zich dan ook op.
Collapse
|
152
|
Antonissen G, Croubels S, Pasmans F, Ducatelle R, Eeckhaut V, Devreese M, Verlinden M, Haesebrouck F, Eeckhout M, De Saeger S, Antlinger B, Novak B, Martel A, Van Immerseel F. Fumonisins affect the intestinal microbial homeostasis in broiler chickens, predisposing to necrotic enteritis. Vet Res 2015; 46:98. [PMID: 26394675 PMCID: PMC4579638 DOI: 10.1186/s13567-015-0234-8] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2015] [Accepted: 07/28/2015] [Indexed: 11/10/2022] Open
Abstract
Fumonisins (FBs) are mycotoxins produced by Fusarium fungi. This study aimed to investigate the effect of these feed contaminants on the intestinal morphology and microbiota composition, and to evaluate whether FBs predispose broilers to necrotic enteritis. One-day-old broiler chicks were divided into a group fed a control diet, and a group fed a FBs contaminated diet (18.6 mg FB1+FB2/kg feed). A significant increase in the plasma sphinganine/sphingosine ratio in the FBs-treated group (0.21 ± 0.016) compared to the control (0.14 ± 0.014) indicated disturbance of the sphingolipid biosynthesis. Furthermore, villus height and crypt depth of the ileum was significantly reduced by FBs. Denaturing gradient gel electrophoresis showed a shift in the microbiota composition in the ileum in the FBs group compared to the control. A reduced presence of low-GC containing operational taxonomic units in ileal digesta of birds exposed to FBs was demonstrated, and identified as a reduced abundance of Candidatus Savagella and Lactobaccilus spp. Quantification of total Clostridium perfringens in these ileal samples, previous to experimental infection, using cpa gene (alpha toxin) quantification by qPCR showed an increase in C. perfringens in chickens fed a FBs contaminated diet compared to control (7.5 ± 0.30 versus 6.3 ± 0.24 log10 copies/g intestinal content). After C. perfringens challenge, a higher percentage of birds developed subclinical necrotic enteritis in the group fed a FBs contaminated diet as compared to the control (44.9 ± 2.22% versus 29.8 ± 5.46%).
Collapse
|
153
|
Hellebuyck T, Pasmans F, Ducatelle R, Saey V, Martel A. Detection of arenavirus in a peripheral odontogenic fibromyxoma in a red tail boa (Boa constrictor constrictor) with inclusion body disease. J Vet Diagn Invest 2015; 27:245-8. [PMID: 25776548 DOI: 10.1177/1040638714562825] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
A captive bred red tail boa (Boa constrictor constrictor) was presented with a large intraoral mass originating from the buccal gingiva, attached to the right dentary teeth row. Based on the clinical features and histological examination, the diagnosis of a peripheral odontogenic fibromyxoma was made. Sections of liver biopsies and circulating lymphocytes contained relatively few eosinophilic intracytoplasmic inclusion bodies, indistinguishable from those observed in inclusion body disease-affected snakes. Inclusion bodies were not observed in cells comprising the neoplastic mass. Using reverse transcription polymerase chain reaction (RT-PCR), arenavirus was detected in the neoplastic tissue. Two years after surgical removal of the mass, recurrence of the neoplastic lesion was observed. Numerous large inclusion body disease inclusions were abundantly present in the neoplastic cells of the recurrent fibromyxoma. Sections of liver biopsies and circulating lymphocytes contained relatively few intracytoplasmic inclusions. The RT-PCR revealed the presence of arenavirus in blood, a liver biopsy, and neoplastic tissue. The present case describes the co-occurrence of an arenavirus infection and an odontogenic fibromyxoma in a red tail boa.
Collapse
|
154
|
Vande Maele L, Heyndrickx M, Maes D, De Pauw N, Mahu M, Verlinden M, Haesebrouck F, Martel A, Pasmans F, Boyen F. In vitro susceptibility of Brachyspira hyodysenteriae to organic acids and essential oil components. J Vet Med Sci 2015; 78:325-8. [PMID: 26369432 PMCID: PMC4785128 DOI: 10.1292/jvms.15-0341] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
The antibacterial potential of organic acids and essential oil components against Brachyspira
hyodysenteriae, the causative pathogen of swine dysentery, was evaluated. Minimum inhibitory
concentrations (MIC) of 15 compounds were determined at pH 7.2 and pH 6.0, using a broth microdilution assay.
In addition, possible synergism was determined. MIC values for the three tested strains were similar. For
organic acids, MIC values at pH 6.0 were lower than at pH 7.2. B. hyodysenteriae was most
sensitive to cinnamaldehyde and lauric acid, with MIC values <1.5 mM. Most antibacterial effects of binary
combinations were additive, however, for thymol and carvacrol, synergism could be observed. In
vitro results demonstrate the antibacterial action of certain essential oil components and organic
acids against B. hyodysenteriae.
Collapse
|
155
|
Mezhoud H, Boyen F, Touazi LH, Garmyn A, Moula N, Smet A, Haesbrouck F, Martel A, Iguer-Ouada M, Touati A. Extended spectrum β-lactamase producing Escherichia coli in broiler breeding roosters: Presence in the reproductive tract and effect on sperm motility. Anim Reprod Sci 2015; 159:205-11. [DOI: 10.1016/j.anireprosci.2015.06.021] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2014] [Revised: 06/17/2015] [Accepted: 06/23/2015] [Indexed: 10/23/2022]
|
156
|
Blooi M, Pasmans F, Rouffaer L, Haesebrouck F, Vercammen F, Martel A. Successful treatment of Batrachochytrium salamandrivorans infections in salamanders requires synergy between voriconazole, polymyxin E and temperature. Sci Rep 2015; 5:11788. [PMID: 26123899 PMCID: PMC4485233 DOI: 10.1038/srep11788] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2015] [Accepted: 06/03/2015] [Indexed: 12/13/2022] Open
Abstract
Chytridiomycosis caused by the chytrid fungus Batrachochytrium salamandrivorans (Bsal) poses a serious threat to urodelan diversity worldwide. Antimycotic treatment of this disease using protocols developed for the related fungus Batrachochytrium dendrobatidis (Bd), results in therapeutic failure. Here, we reveal that this therapeutic failure is partly due to different minimum inhibitory concentrations (MICs) of antimycotics against Bsal and Bd. In vitro growth inhibition of Bsal occurs after exposure to voriconazole, polymyxin E, itraconazole and terbinafine but not to florfenicol. Synergistic effects between polymyxin E and voriconazole or itraconazole significantly decreased the combined MICs necessary to inhibit Bsal growth. Topical treatment of infected fire salamanders (Salamandra salamandra), with voriconazole or itraconazole alone (12.5 μg/ml and 0.6 μg/ml respectively) or in combination with polymyxin E (2000 IU/ml) at an ambient temperature of 15 °C during 10 days decreased fungal loads but did not clear Bsal infections. However, topical treatment of Bsal infected animals with a combination of polymyxin E (2000 IU/ml) and voriconazole (12.5 μg/ml) at an ambient temperature of 20 °C resulted in clearance of Bsal infections. This treatment protocol was validated in 12 fire salamanders infected with Bsal during a field outbreak and resulted in clearance of infection in all animals.
Collapse
|
157
|
Haesendonck R, Verlinden M, Devos G, Michiels T, Butaye P, Haesebrouck F, Pasmans F, Martel A. High seroprevalence of respiratory pathogens in hobby poultry. Avian Dis 2015; 58:623-7. [PMID: 25619008 DOI: 10.1637/10870-052314-resnote.1] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Seroprevalence studies on respiratory pathogens have been done extensively in commercial laying hens, broilers, and, to a lesser extent, backyard poultry. In Europe, seroprevalence studies in backyard and fancy breed poultry flocks are scarce and limited to a few pathogens, such as Mycoplasma gallisepticum (MG); others, such as Ornithobacterium rhinotracheale (ORT), are missing. A commercial ELISA for detection of antibodies against six selected pathogens was performed on 460 serum samples from chickens across Flanders. Anti-ORT antibodies were, by far, the most prevalent, with a prevalence of 95.4%. Infectious bronchitis virus, Mycoplasma synoviae, and avian metapneumovirus antibodies were found in 75.6%, 76.3%, and 63.5% of the animals, respectively. Antibodies against MG and infectious laryngotracheitis virus were found in 36.7% and 30% of the animals, respectively. These data demonstrate the high seroprevalence of respiratory pathogens among hobby poultry; therefore, it is possible that this group could act as a reservoir for commercially kept poultry.
Collapse
|
158
|
Hellebuyck T, Garmyn A, De Cooman L, Boyen F, Pasmans F, Martel A. Mycoplasma columbinum Isolated From a Racing Pigeon ( Columba livia ) With Arthritis. J Avian Med Surg 2015; 28:240-1. [PMID: 25843324 DOI: 10.1647/2013-075] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
A juvenile racing pigeon ( Columba livia ) was presented with drooping of the wing and inability to fly. On physical examination, the right shoulder joint was swollen. The pigeon was euthanatized and submitted for necropsy. An excessive amount of fibrin was present in the canalis triosseus with severe arthritis of the affected shoulder joint. A pure growth of Mycoplasma-like colonies was obtained on microbiological culture of the shoulder joint. A 16S ribosomal RNA gene-specific polymerase chain reaction assay was performed on the isolate and revealed 100% similarity with Mycoplasma columbinum . Although infectious arthritis in homing pigeons is primarily associated with paratyphoid and Streptococcus gallolyticus infection, clinical practitioners should consider the potential role of Mycoplasma columbinum in arthritis in pigeons.
Collapse
|
159
|
Stöhr AC, López-Bueno A, Blahak S, Caeiro MF, Rosa GM, Alves de Matos AP, Martel A, Alejo A, Marschang RE. Phylogeny and differentiation of reptilian and amphibian ranaviruses detected in Europe. PLoS One 2015; 10:e0118633. [PMID: 25706285 PMCID: PMC4338083 DOI: 10.1371/journal.pone.0118633] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2014] [Accepted: 01/21/2015] [Indexed: 11/23/2022] Open
Abstract
Ranaviruses in amphibians and fish are considered emerging pathogens and several isolates have been extensively characterized in different studies. Ranaviruses have also been detected in reptiles with increasing frequency, but the role of reptilian hosts is still unclear and only limited sequence data has been provided. In this study, we characterized a number of ranaviruses detected in wild and captive animals in Europe based on sequence data from six genomic regions (major capsid protein (MCP), DNA polymerase (DNApol), ribonucleoside diphosphate reductase alpha and beta subunit-like proteins (RNR-α and -β), viral homolog of the alpha subunit of eukaryotic initiation factor 2, eIF-2α (vIF-2α) genes and microsatellite region). A total of ten different isolates from reptiles (tortoises, lizards, and a snake) and four ranaviruses from amphibians (anurans, urodeles) were included in the study. Furthermore, the complete genome sequences of three reptilian isolates were determined and a new PCR for rapid classification of the different variants of the genomic arrangement was developed. All ranaviruses showed slight variations on the partial nucleotide sequences from the different genomic regions (92.6–100%). Some very similar isolates could be distinguished by the size of the band from the microsatellite region. Three of the lizard isolates had a truncated vIF-2α gene; the other ranaviruses had full-length genes. In the phylogenetic analyses of concatenated sequences from different genes (3223 nt/10287 aa), the reptilian ranaviruses were often more closely related to amphibian ranaviruses than to each other, and most clustered together with previously detected ranaviruses from the same geographic region of origin. Comparative analyses show that among the closely related amphibian-like ranaviruses (ALRVs) described to date, three recently split and independently evolving distinct genetic groups can be distinguished. These findings underline the wide host range of ranaviruses and the emergence of pathogen pollution via animal trade of ectothermic vertebrates.
Collapse
|
160
|
Antonissen G, Devreese M, Van Immerseel F, De Baere S, Hessenberger S, Martel A, Croubels S. Chronic exposure to deoxynivalenol has no influence on the oral bioavailability of fumonisin B1 in broiler chickens. Toxins (Basel) 2015; 7:560-71. [PMID: 25690690 PMCID: PMC4344641 DOI: 10.3390/toxins7020560] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2014] [Revised: 01/15/2015] [Accepted: 02/09/2015] [Indexed: 02/07/2023] Open
Abstract
Both deoxynivalenol (DON) and fumonisin B1 (FB1) are common contaminants of feed. Fumonisins (FBs) in general have a very limited oral bioavailability in healthy animals. Previous studies have demonstrated that chronic exposure to DON impairs the intestinal barrier function and integrity, by affecting the intestinal surface area and function of the tight junctions. This might influence the oral bioavailability of FB1, and possibly lead to altered toxicity of this mycotoxin. A toxicokinetic study was performed with two groups of 6 broiler chickens, which were all administered an oral bolus of 2.5 mg FBs/kg BW after three-week exposure to either uncontaminated feed (group 1) or feed contaminated with 3.12 mg DON/kg feed (group 2). No significant differences in toxicokinetic parameters of FB1 could be demonstrated between the groups. Also, no increased or decreased body exposure to FB1 was observed, since the relative oral bioavailability of FB1 after chronic DON exposure was 92.2%.
Collapse
|
161
|
Blooi M, Martel A, Haesebrouck F, Vercammen F, Bonte D, Pasmans F. Treatment of urodelans based on temperature dependent infection dynamics of Batrachochytrium salamandrivorans. Sci Rep 2015; 5:8037. [PMID: 25623498 PMCID: PMC5389025 DOI: 10.1038/srep08037] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2014] [Accepted: 12/24/2014] [Indexed: 11/22/2022] Open
Abstract
The recently emerged chytrid fungus Batrachochytrium salamandrivorans currently causes amphibian population declines. We hypothesized that temperature dictates infection dynamics of B. salamandrivorans, and that therefore heat treatment may be applied to clear animals from infection. We examined the impact of environmental temperature on B. salamandrivorans infection and disease dynamics in fire salamanders (Salamandra salamandra). Colonization of salamanders by B. salamandrivorans occurred at 15°C and 20°C but not at 25°C, with a significantly faster buildup of infection load and associated earlier mortality at 15°C. Exposing B. salamandrivorans infected salamanders to 25°C for 10 days resulted in complete clearance of infection and clinically cured all experimentally infected animals. This treatment protocol was validated in naturally infected wild fire salamanders. In conclusion, we show that B. salamandrivorans infection and disease dynamics are significantly dictated by environmental temperature, and that heat treatment is a viable option for clearing B. salamandrivorans infections.
Collapse
|
162
|
Li SJ, Dhaenens M, Garmyn A, Verbrugghe E, Van Rooij P, De Saeger S, Eeckhout M, Ducatelle R, Croubels S, Haesebrouck F, Deforce D, Pasmans F, Martel A. Exposure of Aspergillus fumigatus to T-2 toxin results in a stress response associated with exacerbation of aspergillosis in poultry. WORLD MYCOTOXIN J 2015. [DOI: 10.3920/wmj2014.1765] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Aspergillus fumigatus is a ubiquitous airborne pathogen. Saprophytic growth in the presence of environmental mycotoxins might affect its fitness and virulence. T-2 toxin (T-2) is a trichothecene mycotoxin produced by Fusarium spp. in various substrates. This study aimed to evaluate the effects of T-2 on the fitness of A. fumigatus in vitro and its virulence in experimentally inoculated chickens. We cultured A. fumigatus on agar media containing T-2, and examined the changes in viability, morphology, growth rate, proteome expression, and susceptibility to antimycotics and oxidative stress of this fungus. Results showed that exposure to 1000 ng/ml T-2 in the substrate did not reduce the viability of A. fumigatus, but its growth was inhibited, with wrinkling and depigmentation of the colonies. Proteomic analysis revealed 21 upregulated proteins and 33 downregulated proteins, including those involved in stress response, pathogenesis, metabolism, transcription. The proteome seems to have shifted to enhance the glycolysis, catabolism of lipids, and amino acid conversion. Assays on fungal susceptibility to antimycotics and oxidative stress showed that T-2 exposure did not affect the minimal inhibitory concentrations of amphotericin B, itraconazole, voriconazole and terbinafine against A. fumigatus, but increased the susceptibility of A. fumigatus to H2O2 and menadione. Experimental inoculation of chickens with A. fumigatus showed that exposure of A. fumigatus to T-2 significantly exacerbated aspergillosis in chickens exposed to dietary T-2. In conclusion, A. fumigatus is capable of surviving and growing on substrates containing levels of T-2 up to 1000 ng/ml. Growth in presence of T-2 induces a stress response in A. fumigatus, which is associated with exacerbation of aspergillosis in vivo.
Collapse
|
163
|
Hellebuyck T, Pasmans F, Ducatelle R, Saey V, Bosseler L, Martel A. Arenavirus-associated inclusions in a peripheral odontogenic fibromyxoma in a red-tail boa. J Comp Pathol 2015. [DOI: 10.1016/j.jcpa.2014.10.197] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
|
164
|
Sabino-Pinto J, Bletz M, Hendrix R, Perl RB, Martel A, Pasmans F, Lötters S, Mutschmann F, Schmeller DS, Schmidt BR, Veith M, Wagner N, Vences M, Steinfartz S. First detection of the emerging fungal pathogen Batrachochytrium salamandrivorans in Germany. AMPHIBIA-REPTILIA 2015. [DOI: 10.1163/15685381-00003008] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The emerging infectious disease chytridiomycosis is one of the major factors triggering global amphibian declines. A recently discovered species of chytrid fungus,Batrachochytrium salamandrivorans(Bsal), likely originated in East Asia, has led to massive declines in populations of fire salamanders (Salamandra salamandra) after its apparent introduction to the Netherlands and Belgium. Here, we report the first detection of this pathogen in Germany where it caused mass mortality of fire salamanders in a captive collection. Salamanders from this collection showed an almost 100% prevalence of infection withBsal. SupposedBsal-induced mortality occurred in multipleSalamandraspecies (S. salamandra,S. algira,S. corsica, andS. infraimmaculata), whileBsalinfection was confirmed in nine subspecies ofS. salamandraand inS. algira. Our study indicates that this pathogen can potentially infect all fire salamander species and subspecies. IfBsalspreads from captive collections to wild populations, then a similar devastating effect associated with high mortality should be expected.
Collapse
|
165
|
Mooij TS, Martel A, Bosseler L, Chiers K, Pasmans F, Hellebuyck T. Atypische klinische presentatie van een metastatisch gastrisch neuroendocrien carcinoom bij een baardagame (Pogona vitticeps). VLAAMS DIERGEN TIJDS 2014. [DOI: 10.21825/vdt.v83i6.16627] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Via echografisch onderzoek werd de aanwezigheid van drie intracoelomale, ovoïde massa’s en een nodulair aspect van de lever aangetoond bij een drie jaar oude, mannelijke baardagame (Pogona vitticeps) met anorexie. Het histologisch onderzoek van de operatief verwijderde massa’s en een leverbiopt onthulden de aanwezigheid van neoplastische cellen van neuro-endocriene oorsprong. Via gastroscopisch onderzoek werd een ulceratief letsel in de maag aangetoond. Op basis van deze bevindingen werd er bij de baardagame een vermoedelijke diagnose van een neuro-endocrien carcinoom met uitgebreide metastasen gesteld. Deze diagnose werd bevestigd door autopsie en histologische onderzoeken. Met deze casusbeschrijving willen de auteurs het gastrische, neuro-endocriene carcinoom, een vermoedelijk sterk ondergediagnosticeerde, neoplastische aandoening bij baardagamen, onder de aandacht brengen.
Collapse
|
166
|
Hellebuyck T, Van Steendam K, Deforce D, Blooi M, Van Nieuwerburgh F, Bullaert E, Ducatelle R, Haesebrouck F, Pasmans F, Martel A. Autovaccination confers protection against Devriesea agamarum associated septicemia but not dermatitis in bearded dragons (Pogona vitticeps). PLoS One 2014; 9:e113084. [PMID: 25479609 PMCID: PMC4257540 DOI: 10.1371/journal.pone.0113084] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2014] [Accepted: 10/20/2014] [Indexed: 11/19/2022] Open
Abstract
Devrieseasis caused by Devriesea agamarum is a highly prevalent disease in captive desert lizards, resulting in severe dermatitis and in some cases mass mortality. In this study, we assessed the contribution of autovaccination to devrieseasis control by evaluating the capacity of 5 different formalin-inactivated D. agamarum vaccines to induce a humoral immune response in bearded dragons (Pogona vitticeps). Each vaccine contained one of the following adjuvants: CpG, incomplete Freund's, Ribi, aluminium hydroxide, or curdlan. Lizards were administrated one of the vaccines through subcutaneous injection and booster vaccination was given 3 weeks after primo-vaccination. An indirect ELISA was developed and used to monitor lizard serological responses. Localized adverse effects following subcutaneous immunization were observed in all but the Ribi adjuvanted vaccine group. Following homologous experimental challenge, the incomplete Freund's as well as the Ribi vaccine were observed to confer protection in bearded dragons against the development of D. agamarum associated septicemia but not against dermatitis. Subsequently, two-dimensional gelelectrophoresis followed by immunoblotting and mass spectrometry was conducted with serum obtained from 3 lizards that showed seroconversion after immunisation with the Ribi vaccine. Fructose-bisphosphate aldolase and aldo-keto reductase of D. agamarum reacted with serum from the latter lizards. Based on the demonstrated seroconversion and partial protection against D. agamarum associated disease following the use of formalin-inactivated vaccines as well as the identification of target antigens in Ribi vaccinated bearded dragons, this study provides promising information towards the development of a vaccination strategy to control devrieseasis in captive lizard collections.
Collapse
|
167
|
Fischer D, Van Waeyenberghe L, Cray C, Gross M, Usleber E, Pasmans F, Martel A, Lierz M. Comparison of Diagnostic Tools for the Detection of Aspergillosis in Blood Samples of Experimentally Infected Falcons. Avian Dis 2014; 58:587-98. [DOI: 10.1637/10831-032714-reg] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
|
168
|
Martel A, Blooi M, Adriaensen C, Van Rooij P, Beukema W, Fisher MC, Farrer RA, Schmidt BR, Tobler U, Goka K, Lips KR, Muletz C, Zamudio KR, Bosch J, Lötters S, Wombwell E, Garner TWJ, Cunningham AA, Spitzen-van der Sluijs A, Salvidio S, Ducatelle R, Nishikawa K, Nguyen TT, Kolby JE, Van Bocxlaer I, Bossuyt F, Pasmans F. Wildlife disease. Recent introduction of a chytrid fungus endangers Western Palearctic salamanders. Science 2014; 346:630-1. [PMID: 25359973 DOI: 10.1126/science.1258268] [Citation(s) in RCA: 299] [Impact Index Per Article: 29.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Emerging infectious diseases are reducing biodiversity on a global scale. Recently, the emergence of the chytrid fungus Batrachochytrium salamandrivorans resulted in rapid declines in populations of European fire salamanders. Here, we screened more than 5000 amphibians from across four continents and combined experimental assessment of pathogenicity with phylogenetic methods to estimate the threat that this infection poses to amphibian diversity. Results show that B. salamandrivorans is restricted to, but highly pathogenic for, salamanders and newts (Urodela). The pathogen likely originated and remained in coexistence with a clade of salamander hosts for millions of years in Asia. As a result of globalization and lack of biosecurity, it has recently been introduced into naïve European amphibian populations, where it is currently causing biodiversity loss.
Collapse
|
169
|
Spitzen-Van Der Sluijs A, Martel A, Hallmann CA, Bosman W, Garner TWJ, Van Rooij P, Jooris R, Haesebrouck F, Pasmans F. Environmental determinants of recent endemism of Batrachochytrium dendrobatidis infections in amphibian assemblages in the absence of disease outbreaks. CONSERVATION BIOLOGY : THE JOURNAL OF THE SOCIETY FOR CONSERVATION BIOLOGY 2014; 28:1302-1311. [PMID: 24641583 DOI: 10.1111/cobi.12281] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2012] [Accepted: 12/24/2013] [Indexed: 06/03/2023]
Abstract
The inconsistent distribution of large-scale infection mediated die-offs and the subsequent population declines of several animal species, urges us to understand how, when, and why species are affected by disease. It is often unclear when or under what conditions a pathogen constitutes a threat to a host. Often, variation of environmental conditions plays a role. Globally Batrachochytrium dendrobatidis (Bd) causes amphibian declines; however, host responses are inconsistent and this fungus appears equally capable of reaching a state of endemism and subsequent co-existence with native amphibian assemblages. We sought to identify environmental and temporal factors that facilitate host-pathogen coexistence in northern Europe. To do this, we used molecular diagnostics to examine archived and wild amphibians for infection and general linear mixed models to explore relationships between environmental variables and prevalence of infection in 5 well-sampled amphibian species. We first detected infection in archived animals collected in 1999, and infection was ubiquitous, but rare, throughout the study period (2008-2010). Prevalence of infection exhibited significant annual fluctuations. Despite extremely rare cases of lethal chytridiomycosis in A. obstetricans, Bd prevalence was uncorrelated with this species' population growth. Our results suggest context dependent and species-specific host susceptibility. Thus, we believe recent endemism of Bd coincides with environmentally driven Bd prevalence fluctuations that preclude the build-up of Bd infection beyond the critical threshold for large-scale mortality and host population crashes.
Collapse
|
170
|
Antonissen G, Van Immerseel F, Pasmans F, Ducatelle R, Haesebrouck F, Timbermont L, Verlinden M, Janssens GPJ, Eeckhaut V, Eeckhout M, De Saeger S, Hessenberger S, Martel A, Croubels S. The mycotoxin deoxynivalenol predisposes for the development of Clostridium perfringens-induced necrotic enteritis in broiler chickens. PLoS One 2014; 9:e108775. [PMID: 25268498 PMCID: PMC4182565 DOI: 10.1371/journal.pone.0108775] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2014] [Accepted: 08/25/2014] [Indexed: 11/18/2022] Open
Abstract
Both mycotoxin contamination of feed and Clostridium perfringens-induced necrotic enteritis have an increasing global economic impact on poultry production. Especially the Fusarium mycotoxin deoxynivalenol (DON) is a common feed contaminant. This study aimed at examining the predisposing effect of DON on the development of necrotic enteritis in broiler chickens. An experimental Clostridium perfringens infection study revealed that DON, at a contamination level of 3,000 to 4,000 µg/kg feed, increased the percentage of birds with subclinical necrotic enteritis from 20±2.6% to 47±3.0% (P<0.001). DON significantly reduced the transepithelial electrical resistance in duodenal segments (P<0.001) and decreased duodenal villus height (P = 0.014) indicating intestinal barrier disruption and intestinal epithelial damage, respectively. This may lead to an increased permeability of the intestinal epithelium and decreased absorption of dietary proteins. Protein analysis of duodenal content indeed showed that DON contamination resulted in a significant increase in total protein concentration (P = 0.023). Furthermore, DON had no effect on in vitro growth, alpha toxin production and netB toxin transcription of Clostridium perfringens. In conclusion, feed contamination with DON at concentrations below the European maximum guidance level of 5,000 µg/kg feed, is a predisposing factor for the development of necrotic enteritis in broilers. These results are associated with a negative effect of DON on the intestinal barrier function and increased intestinal protein availability, which may stimulate growth and toxin production of Clostridium perfringens.
Collapse
|
171
|
Canessa S, Martel A, Pasmans F. Designing screening protocols for amphibian disease that account for imperfect and variable capture rates of individuals. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2014; 24:1204-1212. [PMID: 25154107 DOI: 10.1890/13-0103.1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The amphibian chytrid fungus, Batrachochytrium dendrobatidis, is one of the main factors in global amphibian decline. Accurate knowledge of its presence and prevalence in an area is needed to trigger conservation actions. However, imperfect capture rates determine the number of individuals caught and tested during field surveys, and contribute to the uncertainty surrounding estimates of prevalence. Screening programs should be planned with the objective of minimizing such uncertainty. We show how this can be achieved by using predictive models that incorporate information about population size and capture rates. Using as a case study an existing screening program for three populations of the yellow-bellied toad (Bombina variegata pachypus) in northern Italy, we sought to quantify the effect of seasonal variation in individual capture rates on the uncertainty surrounding estimates of chytrid prevalence. We obtained estimates of population size and capture rates from mark-recapture data, and found wide seasonal variation in the individual recapture rates. We then incorporated this information in a binomial model to predict the estimates of prevalence that would be obtained by sampling at different times in the season, assuming no infected individuals were found. Sampling during the period of maximum capture probability was predicted to decrease upper 95% credible intervals by a maximum of 36%, compared with least suitable periods, with greater gains when using uninformative priors. We evaluated model predictions by comparing them with the results of screening surveys in 2012. The observed results closely matched the predicted figures for all populations, suggesting that this method can be reliably used to maximize the sampling size of surveillance programs, thus improving their efficiency.
Collapse
|
172
|
Rouffaer LO, Adriaensen C, De Boeck C, Claerebout E, Martel A. Racing Pigeons: A Reservoir for Nitro-Imidazole–ResistantTrichomonas gallinae. J Parasitol 2014; 100:360-3. [DOI: 10.1645/13-359.1] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
|
173
|
Hermans D, Van Steendam K, Verbrugghe E, Verlinden M, Martel A, Seliwiorstow T, Heyndrickx M, Haesebrouck F, De Zutter L, Deforce D, Pasmans F. Passive immunization to reduce Campylobacter jejuni colonization and transmission in broiler chickens. Vet Res 2014; 45:27. [PMID: 24589217 PMCID: PMC3996517 DOI: 10.1186/1297-9716-45-27] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2013] [Accepted: 02/11/2014] [Indexed: 01/16/2023] Open
Abstract
Campylobacter jejuni is the most common cause of bacterium-mediated diarrheal disease in humans worldwide. Poultry products are considered the most important source of C. jejuni infections in humans but to date no effective strategy exists to eradicate this zoonotic pathogen from poultry production. Here, the potential use of passive immunization to reduce Campylobacter colonization in broiler chicks was examined. For this purpose, laying hens were immunized with either a whole-cell lysate or the hydrophobic protein fraction of C. jejuni and their eggs were collected. In vitro tests validated the induction of specific ImmunoglobulinY (IgY) against C. jejuni in the immunized hens' egg yolks, in particular. In seeder experiments, preventive administration of hyperimmune egg yolk significantly (P < 0.01) reduced bacterial counts of seeder animals three days after oral inoculation with approximately 104 cfu C. jejuni, compared with control birds. Moreover, transmission to non-seeder birds was dramatically reduced (hydrophobic protein fraction) or even completely prevented (whole-cell lysate). Purified IgY promoted bacterial binding to chicken intestinal mucus, suggesting enhanced mucosal clearance in vivo. Western blot analysis in combination with mass spectrometry after two-dimensional gel-electrophoresis revealed immunodominant antigens of C. jejuni that are involved in a variety of cell functions, including chemotaxis and adhesion. Some of these (AtpA, EF-Tu, GroEL and CtpA) are highly conserved proteins and could be promising targets for the development of subunit vaccines.
Collapse
|
174
|
Fard MS, Pasmans F, Adriaensen C, Laing GD, Janssens GPJ, Martel A. Chironomidae bloodworms larvae as aquatic amphibian food. Zoo Biol 2014; 33:221-7. [PMID: 24535989 DOI: 10.1002/zoo.21122] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2013] [Revised: 01/10/2014] [Accepted: 01/27/2014] [Indexed: 11/09/2022]
Abstract
Different species of chironomids larvae (Diptera: Chironomidae) so-called bloodworms are widely distributed in the sediments of all types of freshwater habitats and considered as an important food source for amphibians. In our study, three species of Chironomidae (Baeotendipes noctivagus, Benthalia dissidens, and Chironomus riparius) were identified in 23 samples of larvae from Belgium, Poland, Russia, and Ukraine provided by a distributor in Belgium. We evaluated the suitability of these samples as amphibian food based on four different aspects: the likelihood of amphibian pathogens spreading, risk of heavy metal accumulation in amphibians, nutritive value, and risk of spreading of zoonotic bacteria (Salmonella, Campylobacter, and ESBL producing Enterobacteriaceae). We found neither zoonotic bacteria nor the amphibian pathogens Ranavirus and Batrachochytrium dendrobatidis in these samples. Our data showed that among the five heavy metals tested (Hg, Cu, Cd, Pb, and Zn), the excess level of Pb in two samples and low content of Zn in four samples implicated potential risk of Pb accumulation and Zn inadequacy. Proximate nutritional analysis revealed that, chironomidae larvae are consistently high in protein but more variable in lipid content. Accordingly, variations in the lipid: protein ratio can affect the amount and pathway of energy supply to the amphibians. Our study indicated although environmentally-collected chironomids larvae may not be vectors of specific pathogens, they can be associated with nutritional imbalances and may also result in Pb bioaccumulation and Zn inadequacy in amphibians. Chironomidae larvae may thus not be recommended as single diet item for amphibians.
Collapse
|
175
|
Mahu M, de Jong E, De Pauw N, Vande Maele L, Vandenbroucke V, Vandersmissen T, Miry C, Pasmans F, Haesebrouck F, Martel A, Boyen F. First isolation of “Brachyspira hampsonii”
from pigs in Europe. Vet Rec 2014; 174:47. [DOI: 10.1136/vr.101868] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
|