1
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Lyons K, Dugon MM, Boyd A, Healy K. Venom extraction method influences venom composition and potency in the giant house spider Eratigena atrica (C. L. Koch, 1843). Toxicon 2023; 234:107303. [PMID: 37775046 DOI: 10.1016/j.toxicon.2023.107303] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Revised: 09/19/2023] [Accepted: 09/26/2023] [Indexed: 10/01/2023]
Abstract
Extraction is the first step when investigating venom composition and function. In small invertebrates, widely used extraction methods include electrostimulation and venom gland extraction, however, the influence of these methods on composition and toxicology is poorly understood. Using the Giant House Spider Eratigena atrica as a model, we show that electrostimulation and venom gland removal extraction methods produce different protein profiles as assessed by Coomassie-stained SDS-PAGE and significantly different potencies in the cricket Acheta domesticus.
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Affiliation(s)
- Keith Lyons
- Macroecology Lab, School of Natural Sciences, Ryan Institute, University of Galway, H91 TK33, Galway, Ireland.
| | - Michel M Dugon
- Venom Systems & Proteomics Lab, School of Natural Sciences, Ryan Institute, University of Galway, H91 TK33, Galway, Ireland
| | - Aoife Boyd
- Pathogenic Mechanisms Research Group, School of Natural Sciences, Ryan Institute, University of Galway, H91 TK33, Galway, Ireland
| | - Kevin Healy
- Macroecology Lab, School of Natural Sciences, Ryan Institute, University of Galway, H91 TK33, Galway, Ireland
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2
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Khan NA, Amorim FG, Dunbar JP, Leonard D, Redureau D, Quinton L, Dugon MM, Boyd A. Inhibition of bacterial biofilms by the snake venom proteome. Biotechnol Rep (Amst) 2023; 39:e00810. [PMID: 37559690 PMCID: PMC10407894 DOI: 10.1016/j.btre.2023.e00810] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 08/11/2023]
Abstract
Snake venoms possess a range of pharmacological and toxicological activities. Here we evaluated the antibacterial and anti-biofilm activity against methicillin-susceptible and methicillin-resistant Staphylococcus aureus (MSSA and MRSA) of venoms from the Samar spitting cobra Naja samarensis and the Puff adder Bitis arietans. Both venoms prevented biofilm production by pathogenic S. aureus in a growth-independent manner, with the B. arietans venom being most potent. Fractionation showed the active molecule to be heat-labile and >10 kDa in size. Proteomic profiles of N. samarensis venom revealed neurotoxins and cytotoxins, as well as an abundance of serine proteases and three-finger toxins, while serine proteases, metalloproteinases and C-lectin types were abundant in B. arietans venom. These enzymes may have evolved to prevent bacteria colonising the snake venom gland. From a biomedical biotechnology perspective, they have valuable potential for anti-virulence therapy to fight antibiotic resistant microbes.
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Affiliation(s)
- Neyaz A. Khan
- Pathogenic Mechanisms Research Group, School of Natural Sciences, University of Galway, Ireland
| | | | - John P. Dunbar
- Venom Systems & Proteomics Lab, School of Natural Sciences, Ryan Institute, University of Galway, Ireland
| | - Dayle Leonard
- Pathogenic Mechanisms Research Group, School of Natural Sciences, University of Galway, Ireland
- Venom Systems & Proteomics Lab, School of Natural Sciences, Ryan Institute, University of Galway, Ireland
| | - Damien Redureau
- Mass Spectrometry Laboratory, MolSys RU, University of Liège, Belgium
| | - Loïc Quinton
- Mass Spectrometry Laboratory, MolSys RU, University of Liège, Belgium
| | - Michel M. Dugon
- Venom Systems & Proteomics Lab, School of Natural Sciences, Ryan Institute, University of Galway, Ireland
| | - Aoife Boyd
- Pathogenic Mechanisms Research Group, School of Natural Sciences, University of Galway, Ireland
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3
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Dugon MM, Lawton C, Sturgess D, Dunbar JP. Predation on a pygmy shrew,
Sorex minutus
, by the noble false widow spider,
Steatoda nobilis. Ecosphere 2023. [DOI: 10.1002/ecs2.4422] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/12/2023] Open
Affiliation(s)
- Michel M. Dugon
- Venom Systems & Proteomics Lab School of Natural Sciences, Ryan Institute, University of Galway Galway Ireland
| | - Colin Lawton
- Animal Ecology and Conservation Group School of Natural Sciences, Ryan Institute, University of Galway Galway Ireland
| | - Dawn Sturgess
- Venom Systems & Proteomics Lab School of Natural Sciences, Ryan Institute, University of Galway Galway Ireland
| | - John P. Dunbar
- Venom Systems & Proteomics Lab School of Natural Sciences, Ryan Institute, University of Galway Galway Ireland
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4
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Forde A, Jacobsen A, Dugon MM, Healy K. Scorpion Species with Smaller Body Sizes and Narrower Chelae Have the Highest Venom Potency. Toxins (Basel) 2022; 14:219. [PMID: 35324715 PMCID: PMC8951363 DOI: 10.3390/toxins14030219] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Revised: 03/10/2022] [Accepted: 03/14/2022] [Indexed: 02/04/2023] Open
Abstract
Scorpionism is a global health concern, with an estimation of over one million annual envenomation cases. Despite this, little is known regarding the drivers of scorpion venom potency. One widely held view is that smaller scorpions with less-developed chelae possess the most potent venoms. While this perception is often used as a guide for medical intervention, it has yet to be tested in a formal comparative framework. Here, we use a phylogenetic comparative analysis of 36 scorpion species to test whether scorpion venom potency, as measured using LD50, is related to scorpion body size and morphology. We found a positive relationship between LD50 and scorpion total length, supporting the perception that smaller scorpions possess more potent venoms. We also found that, independent of body size, scorpion species with long narrow chelae have higher venom potencies compared to species with more robust chelae. These results not only support the general perception of scorpion morphology and potency, but also the presence of an ecology trade-off with scorpions either selected for well-developed chelae or more potent venoms. Testing the patterns of venom variations in scorpions aids both our ecological understanding and our ability to address the global health burden of scorpionism.
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Affiliation(s)
- Alannah Forde
- Venom Systems & Proteomics Lab, School of Natural Sciences, Ryan Institute, National University of Ireland Galway, H91 TK33 Galway, Ireland; (A.F.); (A.J.); (M.M.D.)
| | - Adam Jacobsen
- Venom Systems & Proteomics Lab, School of Natural Sciences, Ryan Institute, National University of Ireland Galway, H91 TK33 Galway, Ireland; (A.F.); (A.J.); (M.M.D.)
| | - Michel M. Dugon
- Venom Systems & Proteomics Lab, School of Natural Sciences, Ryan Institute, National University of Ireland Galway, H91 TK33 Galway, Ireland; (A.F.); (A.J.); (M.M.D.)
| | - Kevin Healy
- Macroecology Lab, School of Natural Sciences, Ryan Institute, National University of Ireland Galway, H91 TK33 Galway, Ireland
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5
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Dunbar JP, Vitkauskaite A, Lawton C, Waddams B, Dugon MM. Webslinger vs. Dark Knight First record of a false widow spider
Steatoda nobilis
preying on a pipistrelle bat in Britain. Ecosphere 2022. [DOI: 10.1002/ecs2.3959] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Affiliation(s)
- John P. Dunbar
- Venom Systems & Proteomics Lab, School of Natural Sciences, Ryan Institute National University of Ireland Galway Galway Ireland
| | - Aiste Vitkauskaite
- Venom Systems & Proteomics Lab, School of Natural Sciences, Ryan Institute National University of Ireland Galway Galway Ireland
| | - Colin Lawton
- Animal Ecology and Conservation Group, School of Natural Sciences, Ryan Institute National University of Ireland Galway Galway Ireland
| | - Ben Waddams
- Venom Systems & Proteomics Lab, School of Natural Sciences, Ryan Institute National University of Ireland Galway Galway Ireland
- Ben Waddams Wildlife Art Shropshire UK
| | - Michel M. Dugon
- Venom Systems & Proteomics Lab, School of Natural Sciences, Ryan Institute National University of Ireland Galway Galway Ireland
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6
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Vitkauskaite A, Dunbar JP, Lawton C, Dalagiorgos P, Allen MM, Dugon MM. Vertebrate prey capture by Latrodectus mactans (Walckenaer, 1805) and Steatoda triangulosa (Walckenaer, 1802) (Araneae, Theridiidae) provide further insights into the immobilization and hoisting mechanisms of large prey. Food Webs 2021. [DOI: 10.1016/j.fooweb.2021.e00210] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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7
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Dunbar JP, Vitkauskaite A, O'Keeffe DT, Fort A, Sulpice R, Dugon MM. Clinical evidence of necrosis following bites by the Noble false widow spider Steatoda nobilis - a response to Paolino & colleagues. Clin Toxicol (Phila) 2021; 60:276-277. [PMID: 34282717 DOI: 10.1080/15563650.2021.1955130] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
- John P Dunbar
- Venom Systems & Proteomics Lab, School of Natural Sciences, Ryan Institute, National University of Ireland Galway, Galway, Ireland
| | - Aiste Vitkauskaite
- Venom Systems & Proteomics Lab, School of Natural Sciences, Ryan Institute, National University of Ireland Galway, Galway, Ireland
| | - Derek T O'Keeffe
- School of Medicine, National University of Ireland Galway, Galway, Ireland
| | - Antoine Fort
- Plant Systems Biology Lab, School of Natural Sciences, Ryan Institute & MaREI Centre for Marine, Climate and Energy, National University of Ireland Galway, Galway, Ireland
| | - Ronan Sulpice
- Plant Systems Biology Lab, School of Natural Sciences, Ryan Institute & MaREI Centre for Marine, Climate and Energy, National University of Ireland Galway, Galway, Ireland
| | - Michel M Dugon
- Venom Systems & Proteomics Lab, School of Natural Sciences, Ryan Institute, National University of Ireland Galway, Galway, Ireland
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8
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Dunbar JP, Vitkauskaite A, O'Keeffe DT, Fort A, Sulpice R, Dugon MM. Bites by the noble false widow spider Steatoda nobilis can induce Latrodectus-like symptoms and vector-borne bacterial infections with implications for public health: a case series. Clin Toxicol (Phila) 2021; 60:59-70. [PMID: 34039122 DOI: 10.1080/15563650.2021.1928165] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
CONTEXT In recent years, the Noble false widow spider Steatoda nobilis (Thorell, 1875) has expanded its range globally and may represent a potential threat to native ecosystems and public health. Increasing numbers in synanthropic habitats have led to more human encounters and envenomations. Steatoda nobilis bites were previously classed as medically significant with similarities to bites from true black widows of the genus Latrodectus but deemed milder in onset, with symptoms generally ranging from mild to moderate. CASE DETAILS In this manuscript we present 16 new cases of S. nobilis envenomations bringing the total number of confirmed cases reported in the literature to 24. We report new symptoms and provide discussion on the contributing factors to pathology following bites by S. nobilis. DISCUSSION We report a range of pathologies including necrosis, Latrodectus-like envenomation symptoms that include debilitating pain, tremors, fatigue, nausea, hypotension, and vectored bacterial infections including cellulitis and dermatitis. Symptoms ranged from mild to severe, requiring hospitalisation in some cases.
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Affiliation(s)
- John P Dunbar
- Venom Systems & Proteomics Lab, School of Natural Sciences, Ryan Institute, National University of Ireland Galway, Galway, Ireland
| | - Aiste Vitkauskaite
- Venom Systems & Proteomics Lab, School of Natural Sciences, Ryan Institute, National University of Ireland Galway, Galway, Ireland
| | - Derek T O'Keeffe
- School of Medicine, National University of Ireland Galway, Galway, Ireland
| | - Antoine Fort
- Plant Systems Biology Lab, School of Natural Sciences, Ryan Institute & MaREI Centre for Marine, Climate and Energy, National University of Ireland Galway, Galway, Ireland
| | - Ronan Sulpice
- Plant Systems Biology Lab, School of Natural Sciences, Ryan Institute & MaREI Centre for Marine, Climate and Energy, National University of Ireland Galway, Galway, Ireland
| | - Michel M Dugon
- Venom Systems & Proteomics Lab, School of Natural Sciences, Ryan Institute, National University of Ireland Galway, Galway, Ireland
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9
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Dunbar JP, Khan NA, Abberton CL, Brosnan P, Murphy J, Afoullouss S, O'Flaherty V, Dugon MM, Boyd A. Synanthropic spiders, including the global invasive noble false widow Steatoda nobilis, are reservoirs for medically important and antibiotic resistant bacteria. Sci Rep 2020; 10:20916. [PMID: 33262382 PMCID: PMC7708416 DOI: 10.1038/s41598-020-77839-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Accepted: 11/17/2020] [Indexed: 12/15/2022] Open
Abstract
The false widow spider Steatoda nobilis is associated with bites which develop bacterial infections that are sometimes unresponsive to antibiotics. These could be secondary infections derived from opportunistic bacteria on the skin or infections directly vectored by the spider. In this study, we investigated whether it is plausible for S. nobilis and other synanthropic European spiders to vector bacteria during a bite, by seeking to identify bacteria with pathogenic potential on the spiders. 11 genera of bacteria were identified through 16S rRNA sequencing from the body surfaces and chelicerae of S. nobilis, and two native spiders: Amaurobius similis and Eratigena atrica. Out of 22 bacterial species isolated from S. nobilis, 12 were related to human pathogenicity among which Staphylococcus epidermidis, Kluyvera intermedia, Rothia mucilaginosa and Pseudomonas putida are recognized as class 2 pathogens. The isolates varied in their antibiotic susceptibility: Pseudomonas putida, Staphylococcus capitis and Staphylococcus edaphicus showed the highest extent of resistance, to three antibiotics in total. On the other hand, all bacteria recovered from S. nobilis were susceptible to ciprofloxacin. Our study demonstrates that S. nobilis does carry opportunistic pathogenic bacteria on its body surfaces and chelicerae. Therefore, some post-bite infections could be the result of vector-borne bacterial zoonoses that may be antibiotic resistant.
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Affiliation(s)
- John P Dunbar
- Venom Systems & Proteomics Lab, School of Natural Sciences, Ryan Institute, National University of Ireland Galway, Galway, Ireland.
| | - Neyaz A Khan
- Discipline of Microbiology, School of Natural Sciences and Ryan Institute, National University of Ireland Galway, Galway, Ireland
| | - Cathy L Abberton
- Westway Health Ltd., Unit 120, Business Innovation Centre, National University of Ireland Galway, Galway, Ireland
| | - Pearce Brosnan
- Westway Health Ltd., Unit 120, Business Innovation Centre, National University of Ireland Galway, Galway, Ireland
| | - Jennifer Murphy
- Westway Health Ltd., Unit 120, Business Innovation Centre, National University of Ireland Galway, Galway, Ireland
| | - Sam Afoullouss
- Marine Biodiscovery, School of Chemistry, School of Natural Sciences and Ryan Institute, National University of Ireland Galway, Galway, Ireland
| | - Vincent O'Flaherty
- Discipline of Microbiology, School of Natural Sciences and Ryan Institute, National University of Ireland Galway, Galway, Ireland.,Westway Health Ltd., Unit 120, Business Innovation Centre, National University of Ireland Galway, Galway, Ireland
| | - Michel M Dugon
- Venom Systems & Proteomics Lab, School of Natural Sciences, Ryan Institute, National University of Ireland Galway, Galway, Ireland
| | - Aoife Boyd
- Discipline of Microbiology, School of Natural Sciences and Ryan Institute, National University of Ireland Galway, Galway, Ireland
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10
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Lyons K, Dugon MM, Healy K. Diet Breadth Mediates the Prey Specificity of Venom Potency in Snakes. Toxins (Basel) 2020; 12:toxins12020074. [PMID: 31979380 PMCID: PMC7076792 DOI: 10.3390/toxins12020074] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Revised: 01/15/2020] [Accepted: 01/21/2020] [Indexed: 12/30/2022] Open
Abstract
Venoms are best known for their ability to incapacitate prey. In predatory groups, venom potency is predicted to reflect ecological and evolutionary drivers relating to diet. While venoms have been found to have preyspecific potencies, the role of diet breadth on venom potencies has yet to be tested at large macroecological scales. Here, using a comparative analysis of 100 snake species, we show that the evolution of prey-specific venom potencies is contingent on the breadth of a species' diet. We find that while snake venom is more potent when tested on species closely related to natural prey items, we only find this prey-specific pattern in species with taxonomically narrow diets. While we find that the taxonomic diversity of a snakes' diet mediates the prey specificity of its venom, the species richness of its diet was not found to affect these prey-specific potency patterns. This indicates that the physiological diversity of a species' diet is an important driver of the evolution of generalist venom potencies. These findings suggest that the venoms of species with taxonomically diverse diets may be better suited to incapacitating novel prey species and hence play an important role for species within changing environments.
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Affiliation(s)
- Keith Lyons
- Correspondence: (K.L.); (K.H.); Tel.: +353-91-493744 (K.H.)
| | | | - Kevin Healy
- Correspondence: (K.L.); (K.H.); Tel.: +353-91-493744 (K.H.)
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11
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Dunbar JP, Sulpice R, Dugon MM. The kiss of (cell) death: can venom-induced immune response contribute to dermal necrosis following arthropod envenomations? Clin Toxicol (Phila) 2019; 57:677-685. [PMID: 30806093 DOI: 10.1080/15563650.2019.1578367] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Introduction: Snakes, insects, arachnids and myriapods have been linked to necrosis following envenomation. However, the pathways involved in arthropod venom-induced necrosis remain a highly controversial topic among toxinologists, clinicians and the public. On the one hand, clinicians report on alleged envenomations based on symptoms and the victims' information. On the other hand, toxinologists and zoologists argue that symptoms are incompatible with the known venom activity of target species. This review draws from the literature on arthropod envenomations, snakebite, and inflammatory processes to suggest that envenomation by a range of organisms might trigger an intense inflammatory cascade that ultimately lead to necrosis. If confirmed, these processes would have important implications for the treatment of venom-induced necrosis. Objectives: To describe two inflammatory pathways of regulated necrosis, tumour necrosis factor (necroptosis) and Neutrophil Extracellular Traps (NETosis); to discuss existing knowledge about snake venom and arachnid-induced necrosis demonstrating the involvement of tumour necrosis factor and neutrophils in the development of tissue necrosis following envenomation and to contribute to the understanding of venom-induced necrosis by arthropods and provide clinicians with an insight into little known inflammatory processes which may occur post envenomation. Methods: ISI Web of Science databases were searched using the terms "spider bite necrosis", "arthropod envenomation necrosis", "venom necrosis", "venom immune response", "loxoscelism", "arachnidism", "necroptosis venom", "necroptosis dermatitis", "tumour necrosis factor TNF venom", "scorpionism", "scolopendrism", "centipede necrosis", "NETosis venom", "NETosis necrosis". Searches produced 1737 non-duplicate citations of which 74 were considered relevant to this manuscript. Non-peer-reviewed sources or absence of voucher material identifying the organism were excluded. What is necrosis? Necrosis is the breakdown of cell membrane integrity followed by inflowing extracellular fluid, organelle swelling and the release of proteolytic enzymes into the cytosol. Necrosis was historically considered an unregulated process; however, recent studies demonstrate that necrosis can also be a programmed event resulting from a controlled immune response (necroptosis). Tumour necrosis factor and the necroptosis pathway: Tumour necrosis factor is a pro-inflammatory cytokine involved in regulating immune response, inflammation and cell death/survival. The pro-inflammatory cytokine TNF-α participates in the development of necrosis after envenomation by vipers. Treatment with TNF-α-antibodies may significantly reduce the manifestation of necrosis. Neutrophil Extracellular Traps and the NETosis pathway: The process by which neutrophils discharge a mesh of DNA strands in the extracellular matrix to entangle ("trap") pathogens, preventing them from disseminating. Neutrophil Extracellular Traps have been recently described as important in venom-induced necrosis. Trapped venom accumulates at the bite site, resulting in significant localized necrosis. Arthropod venom driving necrosis: Insects, myriapods and arachnids can induce necrosis following envenomation. So far, the processes involved have only been investigated in two arachnids: Loxosceles spp. (recluse spiders) and Hemiscorpius lepturus (scorpion). Loxosceles venom contains phospholipases D which hydrolyse sphingomyelin, resulting in lysis of muscle fibers. Subsequently liberated ceramides act as intermediaries that regulate TNF-α and recruit neutrophils. Experiments show that immune-deficient mice injected with Loxosceles venom experience less venom-induced inflammatory response and survive longer than control mice. Necrosis following Hemiscorpius lepturus stings correlates with elevated concentrations of TNF-α. These observations suggest that necrosis may be indirectly triggered or worsened by pathways of regulated necrosis in addition to necrotic venom compounds. Conclusions: Envenomation often induce an intense inflammatory cascade, which under certain circumstances may produce necrotic lesions independently from direct venom activity. This could explain the inconsistent and circumstantial occurrence of necrosis following envenomation by a range of organisms. Future research should focus on identifying pathways to regulated necrosis following envenomation and determining more efficient ways to manage inflammation. We suggest that clinicians should consider the victim's immune response as an integral part of the envenomation syndrome.
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Affiliation(s)
- John P Dunbar
- a Venom Systems and Proteomics Lab, School of Natural Sciences , Ryan Institute, National University of Ireland Galway , Galway , Ireland
| | - Ronan Sulpice
- b Plant Systems Biology Laboratory , Plant AgriBiosciences Research Centre, School of Natural Science, Ryan Institute, National University of Ireland Galway , Galway , Ireland
| | - Michel M Dugon
- a Venom Systems and Proteomics Lab, School of Natural Sciences , Ryan Institute, National University of Ireland Galway , Galway , Ireland
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12
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Dunbar JP, Afoullouss S, Sulpice R, Dugon MM. Envenomation by the noble false widow spider Steatoda nobilis (Thorell, 1875) – five new cases of steatodism from Ireland and Great Britain. Clin Toxicol (Phila) 2017; 56:433-435. [DOI: 10.1080/15563650.2017.1393084] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- John P. Dunbar
- Venom Systems & Proteomics Lab, School of Natural Sciences, National University of Ireland Galway, Galway, Republic of Ireland
| | - Sam Afoullouss
- Venom Systems & Proteomics Lab, School of Natural Sciences, National University of Ireland Galway, Galway, Republic of Ireland
| | - Ronan Sulpice
- Venom Systems & Proteomics Lab, School of Natural Sciences, National University of Ireland Galway, Galway, Republic of Ireland
| | - Michel M. Dugon
- Venom Systems & Proteomics Lab, School of Natural Sciences, National University of Ireland Galway, Galway, Republic of Ireland
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13
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Abstract
The requirement for high quality/non-degraded RNA is essential for an array of molecular biology analyses. When analysing the integrity of rRNA from the barnacle Lepas anatifera (Phylum Arthropoda, Subphylum Crustacea), atypical or sub-optimal rRNA profiles that were apparently degraded were observed on a bioanalyser electropherogram. It was subsequently discovered that the rRNA was not degraded, but arose due to a ‘gap deletion’ (also referred to as ‘hidden break’) in the 28S rRNA. An apparent excision at this site caused the 28S rRNA to fragment under heat-denaturing conditions and migrate along with the 18S rRNA, superficially presenting a ‘degraded’ appearance. Examination of the literature showed similar observations in a small number of older studies in insects; however, reading across multiple disciplines suggests that this is a wider issue that occurs across the Animalia and beyond. The current study shows that the 28S rRNA anomaly goes far beyond insects within the Arthropoda and is widespread within this phylum. We confirm that the anomaly is associated with thermal conversion because gap-deletion patterns were observed in heat-denatured samples but not in gels with formaldehyde-denaturing.
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Affiliation(s)
- Sean D McCarthy
- School of Natural Sciences, Ryan Institute for Environmental, Marine and Energy Research, National University of Ireland Galway , Ireland
| | - Michel M Dugon
- School of Natural Sciences, Ryan Institute for Environmental, Marine and Energy Research, National University of Ireland Galway , Ireland
| | - Anne Marie Power
- School of Natural Sciences, Ryan Institute for Environmental, Marine and Energy Research, National University of Ireland Galway , Ireland
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14
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Abstract
In contrast to previous claims that (a) there is a law of recapitulation and, conversely, (b) recapitulation never happens, the evolutionary repatterning of development can take many forms, of which recapitulation is one. Here, we add another example to the list of case studies of recapitulation. This example involves the development of the venom claws (forcipules) in the centipede Scolopendra subspinipes mutilans, and in particular the development of the duct through which venom flows from the gland that produces it (proximal) to the opening called the meatus (distal) through which it is injected into prey. Most of the information we present is from early postembryonic stages--these have been neglected in previous work on centipede development. We show that the venom ducts arise from sutures that are invaginations of the cuticle. In S. s. mutilans, the invagination in each forcipule forms into a tubular structure that detaches itself from the exoskeleton and moves toward the center of the forcipule. This is in contrast to extant Scutigera, and also, probably, Scolopendra's extinct Scutigera-like ancestors, where the duct remains attached to the cuticle of throughout development. Thus, S. s. mutilans exhibits a recapitulatory repatterning of development.
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Affiliation(s)
- Michel M Dugon
- Department of Zoology, School of Natural Sciences, National University of Ireland Galway, University Road, Galway, Ireland.
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15
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Dugon MM, Arthur W. Prey orientation and the role of venom availability in the predatory behaviour of the centipede Scolopendra subspinipes mutilans (Arthropoda: Chilopoda). J Insect Physiol 2012; 58:874-880. [PMID: 22490529 DOI: 10.1016/j.jinsphys.2012.03.014] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2012] [Revised: 03/23/2012] [Accepted: 03/26/2012] [Indexed: 05/31/2023]
Abstract
Many animal phyla contain clades in which most or all species are venom-injecting predators. An example, in the arthropods, is the class Chilopoda, containing the approximately 3500 species of centipedes. Very little ecological or behavioural work yielding quantitative data has been conducted on centipede predation. Here, we describe a study of this kind. Our experiments employed one centipede species - a large tropical one, Scolopendra subspinipes mutilans - and two species of prey - a cricket, Gryllus assimilis, and a locust, Schistocerca gregaria. We conducted two experiments. The first was aimed at investigating the extent to which the centipedes attacked prey in particular tagmata as opposed to at random over the whole body surface. The results showed that the centipedes were highly selective, preferring to attack the head or thorax rather than the abdomen; indeed, they often reoriented the prey in order to achieve this. A possible explanation of this behaviour is to maximize the speed with which the neurotoxins in the venom reach either the brain or the thoracic ganglia that control limb movement. The second experiment was aimed at investigating the effect of venom-extraction on the attack rate, and specifically at testing if the magnitude of any such effect differed between the two types of prey, which differ considerably in size. The results showed a major effect of venom extraction in relation to both types of prey, but with the time taken to return to a 'normal' attack rate being longer in the case of the larger prey-type, namely the locust. We discuss these results in relation to the 'venom optimization hypothesis' and, more generally, to the principle of minimizing the production/use of venom, which is an energetically expensive resource.
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Affiliation(s)
- Michel M Dugon
- Department of Zoology, School of Natural Sciences, National University of Ireland, University Rd, Galway, Ireland.
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Dugon MM, Black A, Arthur W. Variation and specialisation of the forcipular apparatus of centipedes (Arthropoda: Chilopoda): a comparative morphometric and microscopic investigation of an evolutionary novelty. Arthropod Struct Dev 2012; 41:231-243. [PMID: 22370199 DOI: 10.1016/j.asd.2012.02.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2011] [Revised: 02/08/2012] [Accepted: 02/15/2012] [Indexed: 05/31/2023]
Abstract
The forcipules of centipedes are the only known example in the animal kingdom of an evolutionary transition from walking legs to venom-injecting appendages. They provide a classic case of an evolutionary novelty under most (but not all) definitions of that concept. Although there is a reasonable literature on forcipules, and on the forcipular segment more generally, it is fragmentary and scattered. Also, many previous studies have been based on a single species and hence have no comparative component. Here, we build on this earlier literature by providing detailed qualitative and quantitative information on the forcipular segments of representatives of the five extant orders of centipedes. Our results reveal notable differences between the orders - as well as considerable variation within some of them. The pattern of inter-group differences can be used to infer, albeit cautiously, a major evolutionary trend from a presumed scutigeromorph-like last common ancestor (LCA), in which the forcipules were probably leg-like (as in present-day scutigeromorphs) to a more specialized claw-like structure with movement restricted to the horizontal plane. This morphological trend may reflect an ecological trend from open-habitat ambush predation to leaf-litter and subterranean predatory opportunism.
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Affiliation(s)
- Michel M Dugon
- Department of Zoology, School of Natural Sciences, National University of Ireland, Galway, Ireland.
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