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Raaymakers C, Verbrugghe E, Stijlemans B, Martel A, Pasmans F, Roelants K. The anuran skin peptide bradykinin mediates its own absorption across epithelial barriers of the digestive tract. Peptides 2018; 103:84-89. [PMID: 29571654 DOI: 10.1016/j.peptides.2018.03.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/07/2018] [Revised: 03/14/2018] [Accepted: 03/15/2018] [Indexed: 01/23/2023]
Abstract
When faced with a potential predator, a wide range of frog species secrete a mixture of peptide toxins from their skin to defend themselves. We have recently shown that antimicrobial peptides (AMPs) in a frog's defensive poison enhance the uptake of these peptides across epithelia, thereby speeding up the process of predator intoxication. This study provides evidence that bradykinin, a widespread peptide toxin in anurans (frogs), is capable to pass through epithelial barriers independent of this delivery system. We quantified bradykinin peptides secreted by Bombina orientalis during acute stress, and found that at biologically relevant concentrations, bradykinin passage across model epithelia occurs even in the absence of AMPs. Monitoring of transepithelial electric resistance showed that bradykinin treatment caused a subtle yet prolonged reduction in barrier function, indicating that the peptide itself is capable to increase the permeability of epithelia. Yet, bradykinin does not cause cells to leak lactate dehydrogenase, suggesting that it does not damage cell membranes. Moreover, imaging of bradykinin-treated monolayers shows no endocytosis of fluorescent propidium iodide, indicating that the peptide does not perforate cell membranes at smaller scale and therefore is unlikely to cross epithelia via a transcellular passage. Together, these observations suggest that bradykinin, unlike other amphibian neuropeptide toxins, mediates its own passage across mucosal barriers, possibly through a paracellular route. This "self-administering" property, combined with the fact that bradykinins can potently disturb multiple physiological processes, could explain why these peptides are one of the most widespread antipredator peptides in the defensive secretions of frogs.
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Abstract
The use of antifungals in birds is characterized by interspecies and interindividual variability in the pharmacokinetics, affecting drug safety and efficacy. Oral antifungal drug absorption is a complex process affected by drug formulation characteristics, gastrointestinal anatomy, and physiology. New antifungal drug delivery systems can enhance drug stability, reduce off-target side effects, prolong residence time in the blood, and improve efficacy. Topical administration of antifungals through nebulization shows promising results. However, therapeutic output is highly influenced by drug formulation and type of nebulizer, indicating these factors should be taken into account when selecting this medication route.
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Van Waeyenberge J, Aerts J, Hellebuyck T, Pasmans F, Martel A. Stress in wild and captive snakes: quantification, effects and the importance of management. VLAAMS DIERGEN TIJDS 2018. [DOI: 10.21825/vdt.v87i2.16082] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
As in other animals, distress and impaired welfare have a deleterious effect on the mental, physical and behavioral health of snakes in the wild and in captivity. Besides anthropogenic disturbance, the availability of food and shelter, the presence of predators, and environmental factors, such as seasonality and climatological changes, are important factors that affect the stress level and subsequent welfare in wild snake populations. In captive snakes, inappropriate management is the most prominent cause of chronic stress and impaired welfare. Chronic stress can be assumed by looking at the snake’s behavior, but there is need for a standardized quantification method to pin-point more accurately (chronic) stress levels. The biomarker suitable in this framework is the level of corticosterone in plasma, feces and shed skin.
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Van Hecke N, Martel A, Garmyn A, Van de Maele L, Hellebuyck T, Croubels S, Ducatelle R, Antonissen G. Intratumoral chemotherapy in an integumentary squamous cell carcinoma in a cockatiel (Nymphicus hollandicus). VLAAMS DIERGEN TIJDS 2018. [DOI: 10.21825/vdt.v87i2.16085] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
An eight-year-old, female cockatiel (Nymphicus hollandicus) was presented with anorexia, lethargy, a mass at the lower side of the wing and discoloration of the feathers. Physical examination showed an ulcerated nodular integumentary lesion of approximately 4 cm³ ventromedial on the wing at the side of the propatagium and the humerus. Lateral and ventrodorsal radiographs revealed only hepatomegaly. After a stabilization period, surgical excision of the tumor was performed. Based on histopathological evaluation and bacterial culture of the surgically removed tissue, the lesion was typed as an integumentary squamous cell carcinoma with secondary bacterial infection (Corynebacterium sp). Four weeks postoperative, the tumor had recurred. Chemotherapeutic treatment was started with intratumoral carboplatin (1.5 mg/cm³) once a week. Because of further tumor growth 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 evaluations showed degeneration of the tumor with intercellular edema and vacuolization of the tumor cells, presumably resulting from carboplatin administration. More research is needed to investigate the efficacy and safety of the intratumoral administration of carboplatin as a treatment option in birds with integumentary squamous cell carcinoma.
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Martel A, Martiano D, Fisch AL, Pinon F, Baillif S. Combined central retinal vein and cilioretinal artery occlusion related to acute intra-ocular pressure rise of previously unknown pigment dispersion syndrome. J Fr Ophtalmol 2018; 41:e161-e164. [PMID: 29673629 DOI: 10.1016/j.jfo.2017.08.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2017] [Revised: 07/16/2017] [Accepted: 08/16/2017] [Indexed: 11/19/2022]
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106
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Pasmans F, Canessa S, Martel A. The eye of the storm: silent infections driving amphibian declines. Anim Conserv 2018. [DOI: 10.1111/acv.12411] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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More S, Angel Miranda M, Bicout D, Bøtner A, Butterworth A, Calistri P, Depner K, Edwards S, Garin-Bastuji B, Good M, Michel V, Raj M, Saxmose Nielsen S, Sihvonen L, Spoolder H, Stegeman JA, Thulke HH, Velarde A, Willeberg P, Winckler C, Baláž V, Martel A, Murray K, Fabris C, Munoz-Gajardo I, Gogin A, Verdonck F, Gortázar Schmidt C. Risk of survival, establishment and spread of Batrachochytrium salamandrivorans (Bsal) in the EU. EFSA J 2018; 16:e05259. [PMID: 32625888 PMCID: PMC7009437 DOI: 10.2903/j.efsa.2018.5259] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Batrachochytrium salamandrivorans (Bsal) is an emerging fungal pathogen of salamanders. Despite limited surveillance, Bsal was detected in kept salamanders populations in Belgium, Germany, Spain, the Netherlands and the United Kingdom, and in wild populations in some regions of Belgium, Germany and the Netherlands. According to niche modelling, at least part of the distribution range of every salamander species in Europe overlaps with the climate conditions predicted to be suitable for Bsal. Passive surveillance is considered the most suitable approach for detection of Bsal emergence in wild populations. Demonstration of Bsal absence is considered feasible only in closed populations of kept susceptible species. In the wild, Bsal can spread by both active (e.g. salamanders, anurans) and passive (e.g. birds, water) carriers; it is most likely maintained/spread in infected areas by contacts of salamanders or by interactions with anurans, whereas human activities most likely cause Bsal entry into new areas and populations. In kept amphibians, Bsal contamination via live silent carriers (wild birds and anurans) is considered extremely unlikely. The risk-mitigation measures that were considered the most feasible and effective: (i) for ensuring safer international or intra-EU trade of live salamanders, are: ban or restrictions on salamander imports, hygiene procedures and good practice manuals; (ii) for protecting kept salamanders from Bsal, are: identification and treatment of positive collections; (iii) for on-site protection of wild salamanders, are: preventing translocation of wild amphibians and release/return to the wild of kept/temporarily housed wild salamanders, and setting up contact points/emergency teams for passive surveillance. Combining several risk-mitigation measures improve the overall effectiveness. It is recommended to: introduce a harmonised protocol for Bsal detection throughout the EU; improve data acquisition on salamander abundance and distribution; enhance passive surveillance activities; increase public and professionals' awareness; condition any movement of captive salamanders on Bsal known health status.
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Canessa S, Bozzuto C, Campbell Grant EH, Cruickshank SS, Fisher MC, Koella JC, Lötters S, Martel A, Pasmans F, Scheele BC, Spitzen-van der Sluijs A, Steinfartz S, Schmidt BR. Decision-making for mitigating wildlife diseases: From theory to practice for an emerging fungal pathogen of amphibians. J Appl Ecol 2018. [DOI: 10.1111/1365-2664.13089] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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109
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Watteyn A, Devreese M, Plessers E, Wyns H, Garmyn A, Reddy VRAP, Pasmans F, Martel A, Haesebrouck F, De Backer P, Croubels S. Efficacy of gamithromycin against Ornithobacterium rhinotracheale in turkey poults pre-infected with avian metapneumovirus. Avian Pathol 2018; 45:545-51. [PMID: 27171615 DOI: 10.1080/03079457.2016.1183764] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Ornithobacterium rhinotracheale is an avian respiratory pathogen that affects turkeys. The objective of this study was to evaluate the clinical efficacy of gamithromycin (GAM) against O. rhinotracheale in turkeys. The birds were inoculated oculonasally with 10(8) colony-forming units (cfu) of O. rhinotracheale, preceded by infection with avian metapneumovirus. In addition to a negative (CONTR-) and a positive control group (CONTR+) there were two treated groups administered GAM (6 mg/kg) either subcutaneously (GAM SC) or orally (GAM PO) by administration as a single bolus at one-day post-bacterial infection (p.b.i.). From the start of the avian metapneumovirus infection until the end of the experiment, the turkeys were examined clinically and scored daily. In addition, tracheal swabs were collected at several days p.b.i. Necropsy was performed at 4, 8 and 12 days p.b.i. to evaluate the presence of gross lesions, and to collect trachea and lung tissue samples and air sac swabs for O. rhinotracheale quantification. The clinical score of the GAM SC group showed slightly lower values and birds recovered earlier than those in the GAM PO and CONTR+ groups. O. rhinotracheale cfus were significantly reduced in tracheal swabs of the SC group between 2 and 4 days p.b.i. At necropsy, CONTR+ showed higher O. rhinotracheale cfu in lung tissues compared to the treated groups. Moreover, at 8 days p.b.i. only the lung samples of CONTR+ were positive. In conclusion, the efficacy of GAM against O. rhinotracheale was demonstrated, especially in the lung tissue. However, the PO bolus administration of the commercially available product was not as efficacious as the SC bolus.
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Yuan Z, Martel A, Wu J, Van Praet S, Canessa S, Pasmans F. Widespread occurrence of an emerging fungal pathogen in heavily traded Chinese urodelan species. Conserv Lett 2018. [DOI: 10.1111/conl.12436] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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111
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Thomas V, Blooi M, Van Rooij P, Van Praet S, Verbrugghe E, Grasselli E, Lukac M, Smith S, Pasmans F, Martel A. Recommendations on diagnostic tools for Batrachochytrium salamandrivorans. Transbound Emerg Dis 2018; 65:e478-e488. [PMID: 29341499 DOI: 10.1111/tbed.12787] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2017] [Indexed: 02/05/2023]
Abstract
Batrachochytrium salamandrivorans (Bsal) poses a major threat to amphibian, and more specifically caudata, diversity. Bsal is currently spreading through Europe, and mitigation measures aimed at stopping its spread and preventing its introduction into naïve environments are urgently needed. Screening for presence of Bsal and diagnosis of Bsal-induced disease in amphibians are essential core components of effective mitigation plans. Therefore, the aim of this study was to present an overview of all Bsal diagnostic tools together with their limitations and to suggest guidelines to allow uniform interpretation. Here, we investigate the use of different diagnostic tools in post-mortem detection of Bsal and whether competition between Bd and Bsal occurs in the species-specific Bd and Bsal duplex real-time PCR. We also investigate the diagnostic sensitivity, diagnostic specificity and reproducibility of the Bsal real-time PCR and show the use of immunohistochemistry in diagnosis of Bsal-induced chytridiomycosis in amphibian samples stored in formaldehyde. Additionally, we have drawn up guidelines for the use and interpretation of the different diagnostic tools for Bsal currently available, to facilitate standardization of execution and interpretation.
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Hellebuyck T, Göbel S, Pasmans F, Adriaensen C, Martel A. Co-occurrence of Mycoplasma Species and Pigeon Herpesvirus-1 Infection in Racing Pigeons ( Columba livia). J Avian Med Surg 2018; 31:351-355. [PMID: 29327955 DOI: 10.1647/2016-243] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Oropharyngeal swab samples were collected from 438 live racing pigeons ( Columba livia), with and without signs of respiratory disease, that were housed in 220 lofts in 3 provinces in the western part of the Netherlands. Polymerase chain reaction (PCR) was used to identify Mycoplasma species and pigeon herpesvirus-1 (PHV-1) from the samples. In 8.6% of the pigeon lofts tested, signs of respiratory disease were present in pigeons at sampling, and in 30.9% of the sampled pigeon lofts, respiratory signs were observed in pigeons during the 6-month period immediately before sampling. A total of 39.8% of tested pigeons (54.5% of tested lofts) were positive for Mycoplasma species, and 30.6% of tested pigeons (48.6% of tested lofts) were positive for PHV-1. In 15.8% of the tested pigeons (26.8% of tested pigeon lofts), coinfection by Mycoplasma species and PHV-1 was identified. The number of pigeon lofts having pigeons coinfected by Mycoplasma species and PHV-1 was higher than that where only one of the infections was identified. Neither the presence of Mycoplasma species, PHV-1, nor the co-occurrence of both infections was significantly associated with signs of respiratory disease.
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113
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Rouffaer LO, Strubbe D, Teyssier A, Salleh Hudin N, Van den Abeele AM, Cox I, Haesendonck R, Delmée M, Haesebrouck F, Pasmans F, Lens L, Martel A. Effects of urbanization on host-pathogen interactions, using Yersinia in house sparrows as a model. PLoS One 2017; 12:e0189509. [PMID: 29281672 PMCID: PMC5744950 DOI: 10.1371/journal.pone.0189509] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2017] [Accepted: 11/28/2017] [Indexed: 12/01/2022] Open
Abstract
Urbanization strongly affects biodiversity, altering natural communities and often leading to a reduced species richness. Yet, despite its increasingly recognized importance, how urbanization impacts on the health of individual animals, wildlife populations and on disease ecology remains poorly understood. To test whether, and how, urbanization-driven ecosystem alterations influence pathogen dynamics and avian health, we use house sparrows (Passer domesticus) and Yersinia spp. (pathogenic for passerines) as a case study. Sparrows are granivorous urban exploiters, whose western European populations have declined over the past decades, especially in highly urbanized areas. We sampled 329 house sparrows originating from 36 populations along an urbanization gradient across Flanders (Belgium), and used isolation combined with 'matrix-assisted laser desorption ionization- time of flight mass spectrometry' (MALDI-TOF MS) and PCR methods for detecting the presence of different Yersinia species. Yersinia spp. were recovered from 57.43% of the sampled house sparrows, of which 4.06%, 53.30% and 69.54% were identified as Y. pseudotuberculosis, Y. enterocolitica and other Yersinia species, respectively. Presence of Yersinia was related to the degree of urbanization, average daily temperatures and the community of granivorous birds present at sparrow capture locations. Body condition of suburban house sparrows was found to be higher compared to urban and rural house sparrows, but no relationships between sparrows' body condition and presence of Yersinia spp. were found. We conclude that two determinants of pathogen infection dynamics, body condition and pathogen occurrence, vary along an urbanization gradient, potentially mediating the impact of urbanization on avian health.
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Vanmarsenille C, Díaz Del Olmo I, Elseviers J, Hassanzadeh Ghassabeh G, Moonens K, Vertommen D, Martel A, Haesebrouck F, Pasmans F, Hernalsteens JP, De Greve H. Nanobodies targeting conserved epitopes on the major outer membrane protein of Campylobacter as potential tools for control of Campylobacter colonization. Vet Res 2017; 48:86. [PMID: 29216932 PMCID: PMC5721652 DOI: 10.1186/s13567-017-0491-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2017] [Accepted: 11/19/2017] [Indexed: 11/10/2022] Open
Abstract
Campylobacter infections are among the most prevalent foodborne infections in humans, resulting in a massive disease burden worldwide. Broilers have been identified as the major source of campylobacteriosis and reducing Campylobacter loads in the broiler caeca has been proposed as an effective measure to decrease the number of infections in humans. Failure of current methods to control Campylobacter in broilers stresses the urgency to develop novel mitigation measures. We obtained six nanobodies with a broad specificity, that recognize strains belonging to the two most relevant species, Campylobacter jejuni and Campylobacter coli. The target of the nanobodies was identified as the major outer membrane protein, a porin that contributes to bacterial virulence and viability. Multimerization of the nanobodies led to agglutination of C. jejuni cells, which may affect colonization in the chicken gut. These Campylobacter-specific nanobodies may be useful to develop a strategy for preserving chickens from Campylobacter colonization.
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Garmyn A, Verlinden M, Bosseler L, Adriaensen C, Martel A. Persistent Goose Hemorrhagic Polyomavirus Infection on a Belgian Goose Farm. Avian Dis 2017; 61:536-538. [DOI: 10.1637/11604-020317-case.1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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116
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Sercu BK, Baeten L, van Coillie F, Martel A, Lens L, Verheyen K, Bonte D. How tree species identity and diversity affect light transmittance to the understory in mature temperate forests. Ecol Evol 2017; 7:10861-10870. [PMID: 29299264 PMCID: PMC5743659 DOI: 10.1002/ece3.3528] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2017] [Revised: 09/08/2017] [Accepted: 09/16/2017] [Indexed: 11/11/2022] Open
Abstract
Light is a key resource for plant growth and is of particular importance in forest ecosystems, because of the strong vertical structure leading to successive light interception from canopy to forest floor. Tree species differ in the quantity and heterogeneity of light they transmit. We expect decreases in both the quantity and spatial heterogeneity of light transmittance in mixed stands relative to monocultures, due to complementarity effects and niche filling. We tested the degree to which tree species identity and diversity affected, via differences in tree and shrub cover, the spatiotemporal variation in light availability before, during, and after leaf expansion. Plots with different combinations of three tree species with contrasting light transmittance were selected to obtain a diversity gradient from monocultures to three species mixtures. Light transmittance to the forest floor was measured with hemispherical photography. Increased tree diversity led to increased canopy packing and decreased spatial light heterogeneity at the forest floor in all of the time periods. During leaf expansion, light transmittance did differ between the different tree species and timing of leaf expansion might thus be an important source of variation in light regimes for understory plant species. Although light transmittance at the canopy level after leaf expansion was not measured directly, it most likely differed between tree species and decreased in mixtures due to canopy packing. A complementary shrub layer led, however, to similar light levels at the forest floor in all species combinations in our plots. Synthesis. We find that a complementary shrub layer exploits the higher light availability in particular tree species combinations. Resources at the forest floor are thus ultimately determined by the combined effect of the tree and shrub layer. Mixing species led to less heterogeneity in the amount of light, reducing abiotic niche variability.
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Garner TWJ, Schmidt BR, Martel A, Pasmans F, Muths E, Cunningham AA, Weldon C, Fisher MC, Bosch J. Mitigating amphibian chytridiomycoses in nature. Philos Trans R Soc Lond B Biol Sci 2017; 371:rstb.2016.0207. [PMID: 28080996 DOI: 10.1098/rstb.2016.0207] [Citation(s) in RCA: 89] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/12/2016] [Indexed: 12/11/2022] Open
Abstract
Amphibians across the planet face the threat of population decline and extirpation caused by the disease chytridiomycosis. Despite consensus that the fungal pathogens responsible for the disease are conservation issues, strategies to mitigate their impacts in the natural world are, at best, nascent. Reducing risk associated with the movement of amphibians, non-amphibian vectors and other sources of infection remains the first line of defence and a primary objective when mitigating the threat of disease in wildlife. Amphibian-associated chytridiomycete fungi and chytridiomycosis are already widespread, though, and we therefore focus on discussing options for mitigating the threats once disease emergence has occurred in wild amphibian populations. All strategies have shortcomings that need to be overcome before implementation, including stronger efforts towards understanding and addressing ethical and legal considerations. Even if these issues can be dealt with, all currently available approaches, or those under discussion, are unlikely to yield the desired conservation outcome of disease mitigation. The decision process for establishing mitigation strategies requires integrated thinking that assesses disease mitigation options critically and embeds them within more comprehensive strategies for the conservation of amphibian populations, communities and ecosystems.This article is part of the themed issue 'Tackling emerging fungal threats to animal health, food security and ecosystem resilience'.
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Martel A, Butet B, Ramel JC, Martiano D, Baillif S. Medical management of a subretinal Klebsiella pneumoniae abscess with excellent visual outcome without performing vitrectomy. J Fr Ophtalmol 2017; 40:876-881. [PMID: 29162286 DOI: 10.1016/j.jfo.2017.06.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2017] [Revised: 06/25/2017] [Accepted: 06/30/2017] [Indexed: 02/04/2023]
Abstract
OBJECTIVE To report the case of a Klebsiella pneumoniae endogenous endophthalmitis (KPEE) of hepatic and urinary origin that was successfully treated with systemic antibiotherapy and 13 intravitreal antibiotics injections without performing a vitrectomy. PATIENT AND METHOD Case report of a 60-year-old man with a subretinal abscess in the left eye that developed 3 days after initial presentation for K. pneumoniae bacteremia, liver abscess and urinary tract infection. RESULTS Ophthalmic examination of the left eye showed anterior uveitis and a single subretinal abscess located in mid-peripheral temporal retina. BCVA dropped to 20/50. Follow-up was made with clinical examination and multimodal imaging (SD-OCT, FA, ICGA) with high field photographs. A total of 13 intravitreal injections (IVI) of ceftazidime were performed, and no vitrectomy was required. Ocular signs regressed and prognosis was excellent with 20/20 of final BCVA. CONCLUSION KPEE is a rare but severe condition with a typically poor ocular prognosis. When diagnosis is made early, subretinal abscess with partially conserved BCVA could be treated successfully with medical management that includes systemic antibiotics and repeated intravitreal injections without requiring vitrectomy.
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Raaymakers C, Verbrugghe E, Hernot S, Hellebuyck T, Betti C, Peleman C, Claeys M, Bert W, Caveliers V, Ballet S, Martel A, Pasmans F, Roelants K. Antimicrobial peptides in frog poisons constitute a molecular toxin delivery system against predators. Nat Commun 2017; 8:1495. [PMID: 29138448 PMCID: PMC5686178 DOI: 10.1038/s41467-017-01710-1] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2017] [Accepted: 10/10/2017] [Indexed: 01/08/2023] Open
Abstract
Animals using toxic peptides and proteins for predation or defense typically depend on specialized morphological structures, like fangs, spines, or a stinger, for effective intoxication. Here we show that amphibian poisons instead incorporate their own molecular system for toxin delivery to attacking predators. Skin-secreted peptides, generally considered part of the amphibian immune system, permeabilize oral epithelial tissue and enable fast access of cosecreted toxins to the predator's bloodstream and organs. This absorption-enhancing system exists in at least three distantly related frog lineages and is likely to be a widespread adaptation, determining the outcome of predator-prey encounters in hundreds of species.
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Boonyarittichaikij R, Verbrugghe E, Dekeukeleire D, De Beelde R, Rouffaer LO, Haesendonck R, Strubbe D, Mattheus W, Bertrand S, Pasmans F, Bonte D, Verheyen K, Lens L, Martel A. Salmonella Typhimurium DT193 and DT99 are present in great and blue tits in Flanders, Belgium. PLoS One 2017; 12:e0187640. [PMID: 29112955 PMCID: PMC5675436 DOI: 10.1371/journal.pone.0187640] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Accepted: 10/23/2017] [Indexed: 11/29/2022] Open
Abstract
Endemic infections with the common avian pathogen Salmonella enterica subspecies enterica serovar Typhimurium (Salmonella Typhimurium) may incur a significant cost on the host population. In this study, we determined the potential of endemic Salmonella infections to reduce the reproductive success of blue (Cyanistes caeruleus) and great (Parus major) tits by correlating eggshell infection with reproductive parameters. The fifth egg of each clutch was collected from nest boxes in 19 deciduous forest fragments. Out of the 101 sampled eggs, 7 Salmonella Typhimurium isolates were recovered. The low bacterial prevalence was reflected by a similarly low serological prevalence in the fledglings. In this study with a relatively small sample size, presence of Salmonella did not affect reproductive parameters (egg volume, clutch size, number of nestlings and number of fledglings), nor the health status of the fledglings. However, in order to clarify the impact on health and reproduction a larger number of samples have to be analyzed. Phage typing showed that the isolates belonged to the definitive phage types (DT) 193 and 99, and multi-locus variable number tandem repeat analysis (MLVA) demonstrated a high similarity among the tit isolates, but distinction to human isolates. These findings suggest the presence of passerine-adapted Salmonella strains in free-ranging tit populations with host pathogen co-existence.
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Pasmans F, Bogaerts S, Braeckman J, Cunningham AA, Hellebuyck T, Griffiths RA, Sparreboom M, Schmidt BR, Martel A. Future of keeping pet reptiles and amphibians: towards integrating animal welfare, human health and environmental sustainability. Vet Rec 2017; 181:450. [PMID: 29051315 DOI: 10.1136/vr.104296] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2017] [Revised: 08/12/2017] [Accepted: 08/18/2017] [Indexed: 01/24/2023]
Abstract
The keeping of exotic pets is currently under debate and governments of several countries are increasingly exploring the regulation, or even the banning, of exotic pet keeping. Major concerns are issues of public health and safety, animal welfare and biodiversity conservation. The keeping of reptiles and amphibians in captivity encompasses all the potential issues identified with keeping exotic pets, and many of those relating to traditional domestic pets. Within the context of risks posed by pets in general, the authors argue for the responsible and sustainable keeping of reptile and amphibian pets by private persons, based on scientific evidence and on the authors' own expertise (veterinary medicine, captive husbandry, conservation biology).
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Van Rooij P, Pasmans F, Coen Y, Martel A. Efficacy of chemical disinfectants for the containment of the salamander chytrid fungus Batrachochytrium salamandrivorans. PLoS One 2017; 12:e0186269. [PMID: 29023562 PMCID: PMC5638399 DOI: 10.1371/journal.pone.0186269] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2017] [Accepted: 09/28/2017] [Indexed: 12/11/2022] Open
Abstract
The recently emerged chytrid fungus Batrachochytrium salamandrivorans (Bsal) causes European salamander declines. Proper hygiene protocols including disinfection procedures are crucial to prevent disease transmission. Here, the efficacy of chemical disinfectants in killing Bsal was evaluated. At all tested conditions, Biocidal®, Chloramine-T®, Dettol medical®, Disolol®, ethanol, F10®, Hibiscrub®, potassium permanganate, Safe4®, sodium hypochlorite, and Virkon S®, were effective at killing Bsal. Concentrations of 5% sodium chloride or lower, 0.01% peracetic acid and 0.001–1% copper sulphate were inactive against Bsal. None of the conditions tested for hydrogen peroxide affected Bsal viability, while it did kill Batrachochytrium dendrobatidis (Bd). For Bsal, enzymatic breakdown of hydrogen peroxide by catalases and specific morphological features (clustering of sporangia, development of new sporangia within the original sporangium), were identified as fungal factors altering susceptibility to several of the disinfectants tested. Based on the in vitro results we recommend 1% Virkon S®, 4% sodium hypochlorite and 70% ethanol for disinfecting equipment in the field, lab or captive setting, with a minimal contact time of 5 minutes for 1% Virkon S® and 1 minute for the latter disinfectants. These conditions not only efficiently target Bsal, but also Bd and Ranavirus.
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Mahu M, Boyen F, Canessa S, Zavala Marchan J, Haesebrouck F, Martel A, Pasmans F. An avirulent Brachyspira hyodysenteriae strain elicits intestinal IgA and slows down spread of swine dysentery. Vet Res 2017; 48:59. [PMID: 28982389 PMCID: PMC5629781 DOI: 10.1186/s13567-017-0465-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2017] [Accepted: 08/22/2017] [Indexed: 01/08/2023] Open
Abstract
Swine dysentery caused by Brachyspira hyodysenteriae, results in substantial economic losses in swine producing countries worldwide. Although a number of different vaccine approaches have been explored with regard to this disease, they show limitations and none of them have reached the market. We here determine the vaccine potential of a weakly haemolytic B. hyodysenteriae strain. The virulence of this strain was assessed in experimental infection trials and its protection against swine dysentery was quantified in a vaccination-challenge experiment using a seeder infection model. Systemic IgG production and local IgA production were monitored in serum and faeces respectively. Across all trials, pigs that were colonized by virulent, strongly haemolytic B. hyodysenteriae strains consistently developed swine dysentery, in contrast to none of the pigs colonized by the weakly haemolytic B. hyodysenteriae vaccine strain. In the seeder vaccination trial nearly all immunised animals developed swine dysentery on subsequent challenge with a virulent strain, but the speed of spread of swine dysentery and faecal score were significantly reduced in animals immunised with the weakly haemolytic strain compared to sham-immunised animals. The IgA response of immunised animals upon challenge with a virulent B. hyodysenteriae strain significantly correlated to a later onset of disease. The correlation between local IgA production and protection induced by a weakly haemolytic B. hyodysenteriae strain provides leads for future vaccine development against swine dysentery.
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Fischer D, Van Waeyenberghe L, Failing K, Martel A, Lierz M. Single tracheal inoculation of Aspergillus fumigatus conidia induced aspergillosis in juvenile falcons (Falco spp.). Avian Pathol 2017; 47:33-46. [PMID: 28758799 DOI: 10.1080/03079457.2017.1360470] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Aspergillosis is a common and life-threatening respiratory disease in raptors with acute and chronic courses. Among raptors, gyrfalcons (Falco rusticolus) and their hybrids are often declared to be highly susceptible with juvenile individuals being the most susceptible. However, species- and age-specific experimental studies are lacking and minimal infective doses (IDs) for Aspergillus spp. conidia are unknown.Therefore, 8-week-old, healthy gyr-hybrid falcons (F. rusticolus X F. cherrug) (N = 18) were experimentally infected with Aspergillus fumigatus using a single intratracheal inoculation with varying dosages of conidia (102 to 107 conidia). Over 28 days, clinical signs were monitored as well as haematological and serological parameters. Following euthanasia, necropsy, histopathology, bacteriology, and mycology were performed. Re-isolated fungi were compared to the inoculum using microsatellite length polymorphisms. During the trial, clinical signs and dyspnoea correlated significantly with the ID. Necropsy revealed fungal lesions in the upper and lower airways of 10/18 inoculated falcons, but not in the control birds. In 9/18 inoculated falcons, fungal granulomas were confirmed in histopathology and A. fumigatus was re-isolated from these granulomas. Except one nasal isolate all re-isolated fungal strains were identical to the inoculum strain. Based on mycology and histopathology a minimal ID of 50% was calculated to be MID50% (±S.E.) = 104.52±0.67 for a single tracheal inoculation of A. fumigatus conidia. This study demonstrates for the first time that a single exposure is able to cause acute aspergillosis in juvenile falcons.
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Muletz-Wolz CR, Almario JG, Barnett SE, DiRenzo GV, Martel A, Pasmans F, Zamudio KR, Toledo LF, Lips KR. Inhibition of Fungal Pathogens across Genotypes and Temperatures by Amphibian Skin Bacteria. Front Microbiol 2017; 8:1551. [PMID: 28871241 PMCID: PMC5566582 DOI: 10.3389/fmicb.2017.01551] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2017] [Accepted: 07/31/2017] [Indexed: 01/20/2023] Open
Abstract
Symbiotic bacteria may dampen the impacts of infectious diseases on hosts by inhibiting pathogen growth. However, our understanding of the generality of pathogen inhibition by different bacterial taxa across pathogen genotypes and environmental conditions is limited. Bacterial inhibitory properties are of particular interest for the amphibian-killing fungal pathogens (Batrachochytrium dendrobatidis and Batrachochytrium salamandrivorans), for which probiotic applications as conservation strategies have been proposed. We quantified the inhibition strength of five putatively B. dendrobatidis-inhibitory bacteria isolated from woodland salamander skin against six Batrachochytrium genotypes at two temperatures (12 and 18°C). We selected six genotypes from across the Batrachochytrium phylogeny: B. salamandrivorans, B. dendrobatidis-Brazil and four genotypes of the B. dendrobatidis Global Panzootic Lineage (GPL1: JEL647, JEL404; GPL2: SRS810, JEL423). We performed 96-well plate challenge assays in a full factorial design. We detected a Batrachochytrium genotype by temperature interaction on bacterial inhibition score for all bacteria, indicating that bacteria vary in ability to inhibit Batrachochytrium depending on pathogen genotype and temperature. Acinetobacter rhizosphaerae moderately inhibited B. salamandrivorans at both temperatures (μ = 46–53%), but not any B. dendrobatidis genotypes. Chryseobacterium sp. inhibited three Batrachochytrium genotypes at both temperatures (μ = 5–71%). Pseudomonas sp. strain 1 inhibited all Batrachochytrium genotypes at 12°C and four Batrachochytrium genotypes at 18°C (μ = 5–100%). Pseudomonas sp. strain 2 and Stenotrophomonas sp. moderately to strongly inhibited all six Batrachochytrium genotypes at both temperatures (μ = 57–100%). All bacteria consistently inhibited B. salamandrivorans. Using cluster analysis of inhibition scores, we found that more closely related Batrachochytrium genotypes grouped together, suggesting that bacterial inhibition strength may be predictable based on Batrachochytrium relatedness. We conclude that bacterial inhibition capabilities change among bacterial strains, Batrachochytrium genotypes and temperatures. A comprehensive understanding of bacterial inhibitory function, across pathogen genotypes and temperatures, is needed to better predict the role of bacterial symbionts in amphibian disease ecology. For targeted conservation applications, we recommend using bacterial strains identified as strongly inhibitory as they are most likely to produce broad-spectrum antimicrobial agents at a range of temperatures.
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