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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] [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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Mortality caused by venomous animals in Venezuela (2000-2009): A new epidemiological pattern. ACTA ACUST UNITED AC 2021; 41:29-40. [PMID: 33761187 PMCID: PMC8055589 DOI: 10.7705/biomedica.5561] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Indexed: 11/24/2022]
Abstract
Introducción Los accidentes causados por animales venenosos ocurren con mucha frecuencia en comunidades pobres con acceso limitado a los servicios de salud. Se les consideran enfermedades desatendidas y son una de las causas importantes de morbimortalidad en varias naciones del mundo, incluida Venezuela. Objetivo Evaluar la mortalidad por contacto traumático con animales venenosos (serie X20-X29) en Venezuela en el periodo de 2000 a 2009. Materiales y métodos Los datos se obtuvieron de los anuarios de mortalidad del Ministerio de Salud. Resultados Se registraron 759 decesos, la mayoría de ellos en el 2009. La primera causa fue la mordedura de serpientes (n=323; 42,6%), seguida por la picadura de himenópteros (n=170; 22,4%), la mordedura de centípedos (n=106; 14,0%) y la picadura de escorpiones (n=76; 10,0%). La mediana de la tasa de mortalidad general para el periodo fue de 0,285 fallecidos por 100.000 habitantes, en tanto que, por grupo específico, fue de 0,120 para ofidios, de 0,065 para himenópteros, de 0,035 para centípedos y de 0,025 para escorpiones. Conclusión Al comparar estos datos con los antecedentes históricos, se evidenció la modificación del patrón de mortalidad en el país caracterizada por un aumento significativo de los decesos por centípedos, tercera causa de muerte, lo que reubica la picadura de escorpiones como la cuarta causa de mortalidad.
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de Roodt AR. Comments on Environmental and Sanitary Aspects of the Scorpionism by Tityus trivittatus in Buenos Aires City, Argentina. Toxins (Basel) 2014; 6:1434-52. [PMID: 24759176 PMCID: PMC4014744 DOI: 10.3390/toxins6041434] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2014] [Revised: 03/21/2014] [Accepted: 04/03/2014] [Indexed: 11/21/2022] Open
Abstract
Deaths by venomous animals are medical emergencies that can lead to death and thus constitute sanitary problems in some regions of the world. In the South of America, the accidents by these animals are a common sanitary problem especially in warm, tropical or subtropical regions, related with rural work in several countries. Argentina is located in the extreme South of South America and a minor part of the continental surface is in tropical or subtropical regions, where most of the accidents by venomous animals happen. However, in the big cities in the center and South of the country, with no relation to rural work, scorpionism, mostly due to the synanthropic and facultative parthenogenetic scorpion Tityus trivittatus, has become a sanitary problem in the last few decades. This scorpion is present in the biggest cities of Argentina and in the last decades has killed over 20 children in provinces of the center and north of the country, mostly in big cities. In addition, it seems that this species is growing and spreading in new regions of the cities. In this revision, some characteristics of this scorpion regarding its habitat, spreading in Buenos Aires city, combat measures and available treatments are discussed.
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Affiliation(s)
- Adolfo Rafael de Roodt
- Laboratory of Toxinopathology, Center of Applied and Experimental Pathology, Faculty of Medicine, University of Buenos Aires/National Ministry of Health, Uriburu 950, 5 Piso, Lab. 555, Buenos Aires 1114, Argentina.
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Borges A, Rojas-Runjaic FJ, Diez N, Faks JG, Op den Camp HJ, De Sousa L. Envenomation by the Scorpion Tityus breweri in the Guayana Shield, Venezuela: Report of a Case, Efficacy and Reactivity of Antivenom, and Proposal for a Toxinological Partitioning of the Venezuelan Scorpion Fauna. Wilderness Environ Med 2010; 21:282-90. [DOI: 10.1016/j.wem.2010.06.008] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2009] [Revised: 06/03/2010] [Accepted: 06/04/2010] [Indexed: 11/30/2022]
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Borges A, Op den Camp HJM, De Sanctis JB. Specific activation of human neutrophils by scorpion venom: a flow cytometry assessment. Toxicol In Vitro 2010; 25:358-67. [PMID: 20969948 DOI: 10.1016/j.tiv.2010.10.009] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2010] [Revised: 09/22/2010] [Accepted: 10/12/2010] [Indexed: 01/21/2023]
Abstract
Acute lung injury following envenomation by Tityus scorpion species is due in part to activation of the inflammatory response leading to release of cytotoxic leukocyte-derived products, including cytokines and possibly reactive oxygen species (ROS). Tityus zulianus envenomation in Venezuela produces cardiorespiratory complications and death by lung injury whereas stings by Tityus discrepans produce mainly gastrointestinal and pancreatic alterations. To ascertain the role played by granulocytes in the envenomation by T. zulianus (TzV) and T. discrepans (TdV), human peripheral blood neutrophils, eosinophils, and monocytes were exposed to scorpion venoms (0.001-5 μg/mL) and the kinetics (5-15 min) of peroxide production determined by flow cytometry, using 2',7'-dichlorodihydrofluorescein diacetate (succinimidyl ester) as a fluorescent substrate. TzV induced a significantly (p<0.01) more potent increase in peroxide production in neutrophils (for 5 and 10 min of incubation), and to a lesser extent in monocytes (5-15 min), compared to TdV. TzV induced necrosis in neutrophils at doses higher than 5 μg/mL. No effect was observed on eosinophils, suggesting that TzV specifically targets neutrophil intracellular ROS production. The TzV-stimulated pathway is protein kinase C-dependent because it was almost completely (>90%) abolished by staurosporine. The stimulatory effect is associated with the lowest molecular mass venom peptides as gel filtration fractions TzII and TzIII significantly enhanced peroxide production. The combined used of the intracellular ROS agonist, phorbol myristate acetate (PMA), and TzV produced a modest but significant increase in peroxide production suggesting the possibility of overlapping signaling cascades amongst PMA and TzV. Up-regulation of intracellular neutrophil ROS production may be an important in vivo target for TzV which could have a role to play in the cardiorespiratory complications elicited after envenomation by this species.
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Affiliation(s)
- Adolfo Borges
- Instituto de Medicina Experimental, Facultad de Medicina, Universidad Central de Venezuela, Caracas, Venezuela.
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Borges A, Bermingham E, Herrera N, Alfonzo MJ, Sanjur OI. Molecular systematics of the neotropical scorpion genus Tityus (Buthidae): the historical biogeography and venom antigenic diversity of toxic Venezuelan species. Toxicon 2009; 55:436-54. [PMID: 19799925 DOI: 10.1016/j.toxicon.2009.09.011] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2009] [Revised: 08/30/2009] [Accepted: 09/18/2009] [Indexed: 11/30/2022]
Abstract
We provide a mitochondrial DNA-based phylogenetic hypothesis for 21 Tityus species collected in Venezuela, Trinidad, Brazil and Panama, including 12 taxa known to be toxic to humans. Our phylogenetic reconstruction is based on 850 nucleotides of the combined cytochrome oxidase subunit I and 16S rRNA genes for most species, and centered on Venezuelan scorpions owing to the detailed taxonomic and biogeographic information available for Tityus in this region. The principal phylogenetic result was the strong support for mtDNA clades representing geographical groupings associated with the Perijá mountain range, the Mérida Andes, or the central and eastern coastal ranges in Venezuela, suggesting that vicariance has been a potent force in the diversification of local scorpions. Venezuelan Tityus species have been organized by González-Sponga into three artificial morphological groups, "androcottoides", "discrepans", and "nematochirus", based on the array of ventral carinae in metasomal segments II-IV. We also incorporated a fourth morphological group ("Tityus clathratus"), recently documented in Venezuela. Our results do not support the clustering of the species in the "androcottoides" and "discrepans" morphological groups, which include the majority of taxa of medical importance, but provided support for the "nematochirus" species group. T. clathratus was found to cluster with the Brazilian T. serrulatus and T. bahiensis. Divergence times of most clades are consistent with major events in the geological history of northern Venezuela and suggest that many Venezuelan Tityus species formed in the late Miocene and the Pliocene. In turn, we used the Tityus mtDNA phylogeny to determine the potential utility of phylogenetic systematics to predict Tityus venom antigenic reactivity by testing the recognition of T. nororientalis, T. discrepans, T. zulianus, T. perijanensis, and T. clathratus venoms by anti-T. discrepans horse antibodies. Cross-reactivity was significantly higher for the closely related eastern (T. nororientalis) and central coastal (T. discrepans) species in comparison to the distantly related Andean (T. zulianus) and Perijá (T. perijanensis) species. Reactivity of T. clathratus low mol. mass toxic components towards anti-T. serrulatus and anti-T. discrepans antivenoms was low, suggesting that venom components produced by the subgenus Archaeotityus (which encompass "clathratus" species) diverge antigenically from other Tityus scorpions.
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Affiliation(s)
- Adolfo Borges
- Instituto de Medicina Experimental, Facultad de Medicina, Universidad Central de Venezuela, Caracas, Venezuela.
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7
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Albuquerque CMRD, Porto TJ, Amorim MLP, Santana Neto PDL. Escorpionismo por Tityus pusillus Pocock, 1893 (Scorpiones; Buthidae) no Estado de Pernambuco. Rev Soc Bras Med Trop 2009; 42:206-8. [DOI: 10.1590/s0037-86822009000200023] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2009] [Accepted: 03/20/2009] [Indexed: 11/22/2022] Open
Abstract
Apresentamos neste trabalho os primeiros relatos de acidente escorpiônico causado pela espécie Tityus pusillus (Buthidae). Os acidentes ocorreram no ambiente doméstico, na área rural situada nas cidades de Paudalho e São Lourenço da Mata, Pernambuco, Brasil. Os dois casos descritos, uma criança e uma mulher grávida, foram classificados como leve e moderado, respectivamente. Os sintomas clínicos apresentados foram distúrbios locais (dor e parestesia) e distúrbios sistêmicos (calafrios, tontura, cefaléia e vômito). Esses registros permitem incluir Tityus pusillus como uma espécie de importância médica no Brasil.
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Kiriakos D, Núñez P, Parababire Y, García M, Medina J, Sousa LD. First case of human latrodectism in Venezuela. Rev Soc Bras Med Trop 2008; 41:202-4. [PMID: 18545846 DOI: 10.1590/s0037-86822008000200015] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2007] [Accepted: 02/25/2008] [Indexed: 11/22/2022] Open
Abstract
The first case of envenoming by Latrodectus geometricus in Venezuela is described. The accident occurred at the victims home, in Aragua de Barcelona, Anzoátegui State. The 31-year-old female victim was bitten twice on the left scapular region, in quick succession (within seconds). She developed a hyperactive state of the central, autonomic and peripheral nervous systems with minor local symptoms.
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Affiliation(s)
- Demetrio Kiriakos
- Departamento de Medicina Interna, Escuela de Ciencias de la Salud, Universidad de OrienteAnzoátegui, Venezuela
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Chippaux JP, Goyffon M. Epidemiology of scorpionism: a global appraisal. Acta Trop 2008; 107:71-9. [PMID: 18579104 DOI: 10.1016/j.actatropica.2008.05.021] [Citation(s) in RCA: 366] [Impact Index Per Article: 22.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2008] [Revised: 05/20/2008] [Accepted: 05/29/2008] [Indexed: 10/22/2022]
Abstract
The scorpionism is an actual public health problem in several parts of the world because, either incidence, or severity of envenomations is high and managed with difficulty by health services, or for these two reasons at the same time. The treatment of scorpion envenomation is complex and controversial, in particular regarding the utility of the antivenoms and symptomatic treatments that must be associated. The authors reviewed the literature of last 30 years to discuss the epidemiologic importance of scorpionism and to point out the principal therapeutic or preventive measures. According to the most recent studies, seven areas were identified as at risk: north-Saharan Africa, Sahelian Africa, South Africa, Near and Middle-East, South India, Mexico and South Latin America, east of the Andes. These involve 2.3 billion at risk population. The annual number of scorpion stings exceeds 1.2 million leading to more than 3250 deaths (0.27%). Although adults are more often concerned, children experience more severe envenomations and among them, mortality is higher. Improvement of therapeutic management would reduce the lethality very significantly.
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Abstract
BACKGROUND Information on scorpion stings is available for many parts of Saudi Arabia, but not for Al-Jouf Province. METHODS We reviewed and analyzed 1449 cases of scorpion stings that presented to the emergency department of the hospitals and medical centers in Al-Jouf Province during a 2-year period (2005-2006). RESULTS The majority of patients (92.7%) manifested class I envenomation with local pain at the sting site as the primary complaint. Systemic toxicity was noticed in 7.3% of cases but no deaths were reported. Scorpion stings were recorded throughout the year with the highest seasonal incidence in the summer (64.3%) and the lowest during the winter (10.6%). The highest monthly incidence was in June (21.5%) and the lowest in December (1.5%). Most of the patients were male (77.3%) and the age of 44.2% of victims ranged between 15 to 30 years. Diurnal stings exceeded the nocturnal ones with a ratio of 3:2, and most of the stings were located mainly on the exposed limbs (88.6%), especially the lower limbs (51.7%). Leiurus quinquestriatus and Androctonus crassicauda were incriminated in most recorded cases. CONCLUSIONS Our findings indicate that scorpion stings are common in Al-Jouf Province, especially during the summer. The overall threat to human health was found to be low.
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Affiliation(s)
- Bashir M Jarrar
- Clinical Laboratory Sciences, Al-Jouf University, Al-Jouf, Saudi Arabia
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11
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Borges A, De Sousa L, Espinoza J, Santos RG, Kalapothakis E, Valadares D, Chávez-Olórtegui C. Characterization of Tityus scorpion venoms using synaptosome binding assays and reactivity towards Venezuelan and Brazilian Antivenoms. Toxicon 2008; 51:66-79. [DOI: 10.1016/j.toxicon.2007.08.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2007] [Revised: 08/13/2007] [Accepted: 08/14/2007] [Indexed: 10/22/2022]
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Borges A, Rojas-Runjaic FJM. Tityus perijanensis González-Sponga (Scorpiones, Buthidae): Molecular assessment of its geographical distribution and venom lethality of Venezuelan populations. Toxicon 2007; 50:1005-10. [PMID: 17868753 DOI: 10.1016/j.toxicon.2007.07.019] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2007] [Revised: 07/24/2007] [Accepted: 07/25/2007] [Indexed: 10/23/2022]
Abstract
An extensive field survey allowed us to expand the geographical distribution of the scorpion Tityus perijanensis in the Perijá range, western Zulia State, Venezuela, including areas where adult cases of severe scorpionism have been reported. 16S ribosomal RNA (rRNA) gene sequencing, DL(50) determination, and native PAGE suggest low genetic and venom proteomic divergence across the distribution range. The results also indicate phylogenetic divergence between T. perijanensis and T. discrepans, the species prevalent in northcentral Venezuela. T. perijanensis venom lethality (0.91-0.94 mg/kg) is comparable to that of the Brazilian T. serrulatus and ranks highest among toxic Venezuelan Tityus studied so far. The data indicate that the Perijá range should be included amongst the endemic areas of scorpionism of Venezuela and Colombia.
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Affiliation(s)
- Adolfo Borges
- Laboratorio de Toxinas Animales, Centro de Biociencias y Medicina Molecular, Instituto de Estudios Avanzados, Caracas, Venezuela.
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De Sousa L, Boadas J, Kiriakos D, Borges A, Boadas J, Marcano J, Turkali I, De Los Ríos M. Scorpionism due to Tityus neoespartanus (Scorpiones, Buthidae) in Margarita Island, northeastern Venezuela. Rev Soc Bras Med Trop 2007; 40:681-5. [DOI: 10.1590/s0037-86822007000600017] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2007] [Accepted: 11/06/2007] [Indexed: 11/22/2022] Open
Abstract
The first two cases of scorpion envenoming caused by Tityus neoespartanus (Buthidae) are described. The accidents took place within human environments (one inside a home and the other inside a school), in the village of La Sierra, Margarita Island, State of Nueva Esparta, northeastern Venezuela. Both cases were moderately severe and developed pancreatic involvement and electrocardiographic abnormalities. This report allows inclusion of Margarita Island among the endemic areas of scorpionism in Venezuela.
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Affiliation(s)
- Leonardo De Sousa
- Universidad de Oriente, Venezuela; Universidad de Oriente, Venezuela
| | | | - Demetrio Kiriakos
- Universidad de Oriente, Venezuela; Universidad de Oriente, Venezuela
| | - Adolfo Borges
- Instituto de Estudios Avanzados, Venezuela; Universidad Central de Venezuela, Venezuela
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Borges A, Silva S, Op den Camp HJM, Velasco E, Alvarez M, Alfonzo MJM, Jorquera A, De Sousa L, Delgado O. In vitro leishmanicidal activity of Tityus discrepans scorpion venom. Parasitol Res 2006; 99:167-73. [PMID: 16538481 DOI: 10.1007/s00436-006-0133-z] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2005] [Accepted: 01/19/2006] [Indexed: 10/24/2022]
Abstract
Leishmania parasites are sensitive to peptides with antimicrobial and ion-channel inhibitory activity. Because scorpion venoms are rich sources of such peptides, the leishmanicidal effect of Tityus discrepans venom was investigated. A negative correlation between cell growth and venom concentration was observed for venom-treated cultures of Leishmania (L.) mexicana mexicana promastigotes; 50% growth inhibition was obtained at 0.4 microg/ml. Light microscopy showed rounded, highly vacuolated L. (L.) m. mexicana cells with impaired flagellar motion after 15 min of incubation at 35 microg/ml. Ultrastructural studies confirmed an intense cytoplasm vacuolation and also enlargement of the flagellar pocket. Survival rates for New World Leishmania promastigotes (75% venom effective concentration, microg/ml) obtained after acute (1 h) venom toxicity tests were: L. (L.) m. mexicana (2.3), Leishmania (V.) braziliensis (11.3), and Leishmania (L.) chagasi (56.2). Heat (90 degrees C) treatment of venom and fraction TdII abolished most of their leishmanicidal effect. Acute toxicity assays performed with Sephadex G-50 fractions indicated that leishmanicidal activity is associated with the venom lowest molecular mass components (2.8-7.4 kDa), as determined by MALDI-TOF mass spectrometry.
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Affiliation(s)
- Adolfo Borges
- Institute of Experimental Medicine, Central University of Venezuela, Box 50587, Sabana Grande, Caracas 1051, Venezuela.
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15
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Borges A, García CC, Lugo E, Alfonzo MJ, Jowers MJ, Op den Camp HJM. Diversity of long-chain toxins in Tityus zulianus and Tityus discrepans venoms (Scorpiones, Buthidae): molecular, immunological, and mass spectral analyses. Comp Biochem Physiol C Toxicol Pharmacol 2006; 142:240-252. [PMID: 16356783 DOI: 10.1016/j.cbpc.2005.10.011] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/27/2005] [Revised: 10/11/2005] [Accepted: 10/12/2005] [Indexed: 11/27/2022]
Abstract
In Venezuela, stings by Tityus zulianus scorpions produce cardiorespiratory arrest, whereas envenoming by Tityus discrepans involves gastrointestinal/pancreatic complications, suggesting structural and/or functional differences. We sought to compare their toxin repertoires through immunological, molecular, and mass spectral analyses. First, in vivo tests showed that neutralization of T. zulianus venom toxicity by the anti-T. discrepans antivenom was not complete. To compare T. discrepans and T. zulianus long-chain (sodium channel-active) toxins, their most toxic Sephadex G-50 fractions, TdII and TzII, were subjected to acid-urea PAGE, which showed differences in composition. Amplification of toxin-encoding mRNAs using a leader peptide-based oligonucleotide rendered cDNAs representing twelve T. discrepans and two T. zulianus distinct toxin transcripts, including only one shared component, indicating divergence between T. zulianus and T. discrepans 5' region-encoded, toxin signal peptides. A 3'-UTR polymorphism was also noticed among the transcripts encoding shared components Tz1 and Td4. MALDI-TOF MS profiling of TdII and TzII produced species-specific spectra, with seven of the individual masses matching those predicted by cDNA sequencing. Phylogenetic analysis showed that the unique T. zulianus transcript-encoded sequence, Tz2, is structurally related to Tityus serrulatus and Centruroides toxins. Together with previous reports, this work indicates that T. zulianus and T. discrepans toxin repertoires differ structurally and functionally.
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Affiliation(s)
- Adolfo Borges
- Sección de Biomembranas, Instituto de Medicina Experimental, Universidad Central de Venezuela, Caracas 1051, Venezuela.
| | - Carmen C García
- Sección de Biomembranas, Instituto de Medicina Experimental, Universidad Central de Venezuela, Caracas 1051, Venezuela
| | - Elizabeth Lugo
- Sección de Biomembranas, Instituto de Medicina Experimental, Universidad Central de Venezuela, Caracas 1051, Venezuela
| | - Marcelo J Alfonzo
- Sección de Biomembranas, Instituto de Medicina Experimental, Universidad Central de Venezuela, Caracas 1051, Venezuela
| | - Michael J Jowers
- Institute of Biomedical and Life Sciences, Division of Molecular Genetics, University of Glasgow, Glasgow G11 6NU, United Kingdom
| | - Huub J M Op den Camp
- Department of Microbiology, Faculty of Science, Radboud University Nijmegen, Tooernooiveld 1, Nijmegen, The Netherlands
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16
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Borges A, Alfonzo MJ, García CC, Winand NJ, Leipold E, Heinemann SH. Isolation, molecular cloning and functional characterization of a novel beta-toxin from the Venezuelan scorpion, Tityus zulianus. Toxicon 2004; 43:671-84. [PMID: 15109888 DOI: 10.1016/j.toxicon.2004.02.022] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2003] [Revised: 02/26/2004] [Accepted: 02/27/2004] [Indexed: 11/18/2022]
Abstract
Sting in children by Tityus zulianus scorpions (western Venezuela) often produces cardiorespiratory arrest and death by pulmonary oedema. To assess its toxicity, lethality in mice of T. zulianus soluble venom was determined. Toxin composition was studied by fractionating the crude venom through reversed-phase HPLC. The most abundant peptide, Tz1, was purified further and its N-terminal sequence, amino acid composition and molecular mass (by electron-spray ionization mass spectrometry) determined. In the presence of Tz1, activation of recombinant rat skeletal muscle sodium channels (Na(V)1.4) was shifted about 35 mV in the hyperpolarizing direction in a prepulse-dependent manner. This typical beta-toxin effect had an apparent EC50 of 3.5 microM A cDNA sequence encoding Tz1 was isolated from T. zulianus venom gland RNA using a combination of 5'- and 3'-RACE PCR. Analysis of the encoded sequence indicated that Tz1 is the processed product of a precursor containing: (i) a 20-residue long leader peptide; (ii) the amino acid sequence of the mature toxin (64 residues); and (iii) an extra Gly-Lys tail at the C-terminus, probably removed post-translationally. A comparison of Tz1 with Tityus serrulatus beta-toxin Ts1 revealed that some of the non-conservative replacements in Tz1 lie in regions potentially involved in receptor recognition.
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Affiliation(s)
- Adolfo Borges
- Sección de Biomembranas, Instituto de Medicina Experimental, Facultad de Medicina, Universidad Central de Venezuela, Box 50587, Sabana Grande, Caracas 1051, Venezuela.
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Amorim AMD, Carvalho FM, Lira-da-Silva RM, Brazil TK. Acidentes por escorpião em uma área do Nordeste de Amaralina, Salvador, Bahia, Brasil. Rev Soc Bras Med Trop 2003. [DOI: 10.1590/s0037-86822003000100008] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Um estudo epidemiológico mediu a prevalência de pessoas que referiram acidentes por escorpião em uma amostra populacional do Areal, bairro Nordeste de Amaralina, Salvador, Bahia. Examinou-se uma amostra aleatória sistemática de 1367 indivíduos, correspondendo a 44,4% da população da área. Oitenta e dois indivíduos referiram haver sido picados por escorpião desde que residiam no Areal, resultando numa prevalência de 6% (IC 95% 4,7 - 7,3). A prevalência de pessoas picadas por escorpião aumentou nos grupos com maior tempo de residência no domicílio e com maior idade atual. Chamou atenção que 92,7% dos acidentes aconteceram dentro do domicílio. A incidência estimada para o período mais recente (janeiro a julho de 2000) foi de 1,15 casos/1.000 habitantes por mês. Este coeficiente compara-se ao mais elevado já referido na literatura especializada para uma área epidêmica para acidentes escorpiônicos.
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