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Kono IS, Pandolfi VCF, Marchi MNAD, Freitas N, Freire RL. Unveiling the secrets of snakes: Analysis of environmental, socioeconomic, and spatial factors associated with snakebite risk in Paraná, Southern Brazil. Toxicon 2024; 237:107552. [PMID: 38065257 DOI: 10.1016/j.toxicon.2023.107552] [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] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2023] [Revised: 11/29/2023] [Accepted: 12/03/2023] [Indexed: 12/24/2023]
Abstract
The state of Paraná is home to three out of the five medically significant snake genera in Brazil and lacks of snakebite epidemiology studies. This study aimed to ascertain the spatial, environmental, and socioeconomic factors associated with snakebite risk by analyzing notification data of cases in the state of Paraná. Notification and socioeconomic data were gathered from the online platforms of the National System of Notifiable Diseases (SINAN) and the Brazilian Institute of Geography and Statistics (IBGE). Land cover and land use maps were obtained from the Mapbiomas platform in raster format and subsequently converted into vectors using QGis software. The proportions of land use and land cover in square kilometers (km2) were then calculated. All acquired data were tabulated using Microsoft Excel 365 software. For spatial analysis, GeoDa software version 1.20 was utilized to calculate the Global and Local Moran indices, assessing spatial correlations. Between 2007 and 2021, 12,877 notifications were recorded, with an average incidence of 8.22/100,000 inhabitants in the state, 8166 (63.41%) caused by Bothrops, 1534 (11.91%) caused by Crotalus, 56 (0.43%) caused by Micrurus. 1703 (13.22%) caused by non-venomous snake species, and the remaining cases did not have the identified causative species. The incidents caused by Bothrops and Crotalus showed different distribution patterns. Spatial analysis revealed that key factors contributing to snakebite risk included the presence of native forests, mangroves, apicuns, and monospecific planted forests. The population group at the highest risk comprised rural residents and workers. Furthermore, the absence of basic sanitation and proper garbage collection and disposal exhibited positive correlations with snakebites. Conversely, intensive farming practices with substantial mechanization and pastures demonstrated negative spatial correlations. This study has enabled the identification of the primary factors associated with snakebite risk, facilitating more targeted efforts to prevent snakebite accidents among vulnerable populations.
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Affiliation(s)
- Isabelli Sayuri Kono
- Departamento de Medicina Veterinária Preventiva, Universidade Estadual de Londrina, Londrina, 86057970, Paraná, Brazil.
| | | | - Melca Niceia Altoé de Marchi
- Departamento de Ciências Agrárias e Ambientais, Universidade Estadual de Santa Cruz, Ilhéus, 45662900, Bahia, Brazil.
| | - Nicolas Freitas
- Departamento de Geociências, Universidade Estadual de Londrina, Londrina, 86057970, Paraná, Brazil.
| | - Roberta Lemos Freire
- Departamento de Medicina Veterinária Preventiva, Universidade Estadual de Londrina, Londrina, 86057970, Paraná, Brazil.
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Hernández-Altamirano JA, Salazar-Valenzuela D, Medina-Villamizar EJ, Quirola DR, Patel K, Vaiyapuri S, Lomonte B, Almeida JR. First Insights into the Venom Composition of Two Ecuadorian Coral Snakes. Int J Mol Sci 2022; 23:ijms232314686. [PMID: 36499012 PMCID: PMC9740791 DOI: 10.3390/ijms232314686] [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] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Revised: 11/16/2022] [Accepted: 11/22/2022] [Indexed: 11/27/2022] Open
Abstract
Micrurus is a medically relevant genus of venomous snakes composed of 85 species. Bites caused by coral snakes are rare, but they are usually associated with very severe and life-threatening clinical manifestations. Ecuador is a highly biodiverse country with a complex natural environment, which is home to approximately 20% of identified Micrurus species. Additionally, it is on the list of Latin American countries with the highest number of snakebites. However, there is no local antivenom available against the Ecuadorian snake venoms, and the biochemistry of these venoms has been poorly explored. Only a limited number of samples collected in the country from the Viperidae family were recently characterised. Therefore, this study addressed the compositional patterns of two coral snake venoms from Ecuador, M. helleri and M. mipartitus, using venomics strategies, integrating sample fractionation, gel electrophoresis, and mass spectrometry. Chromatographic and electrophoretic profiles of these snake venoms revealed interspecific variability, which was ascertained by mass spectrometry. The two venoms followed the recently recognised dichotomic toxin expression trends displayed by Micrurus species: M. helleri venom contains a high proportion (72%) of phospholipase A2, whereas M. mipartitus venom is dominated by three-finger toxins (63%). A few additional protein families were also detected in these venoms. Overall, these results provide the first comprehensive views on the composition of two Ecuadorian coral snake venoms and expand the knowledge of Micrurus venom phenotypes. These findings open novel perspectives to further research the functional aspects of these biological cocktails of PLA2s and 3FTxs and stress the need for the preclinical evaluation of the currently used antivenoms for therapeutic purposes in Ecuador.
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Affiliation(s)
| | - David Salazar-Valenzuela
- Centro de Investigación de la Biodiversidad y Cambio Climático (BioCamb) e Ingeniería en Biodiversidad y Recursos Genéticos, Facultad de Ciencias de Medio Ambiente, Universidad Indoamérica, Quito 180103, Ecuador
| | | | - Diego R. Quirola
- Centro de Investigación de la Biodiversidad y Cambio Climático (BioCamb) e Ingeniería en Biodiversidad y Recursos Genéticos, Facultad de Ciencias de Medio Ambiente, Universidad Indoamérica, Quito 180103, Ecuador
| | - Ketan Patel
- School of Biological Sciences, University of Reading, Reading RG6 6UB, UK
| | | | - Bruno Lomonte
- Instituto Clodomiro Picado, Facultad de Microbiología, Universidad de Costa Rica, San Jose 11501, Costa Rica
| | - José R. Almeida
- Biomolecules Discovery Group, Universidad Regional Amazónica Ikiam, Km 8 Via Muyuna, Tena 150101, Ecuador
- School of Pharmacy, University of Reading, Reading RG6 6UB, UK
- Correspondence:
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Baudou FG, Rodriguez JP, Fusco L, de Roodt AR, De Marzi MC, Leiva L. South American snake venoms with abundant neurotoxic components. Composition and toxicological properties. A literature review. Acta Trop 2021; 224:106119. [PMID: 34481791 DOI: 10.1016/j.actatropica.2021.106119] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Revised: 08/18/2021] [Accepted: 08/19/2021] [Indexed: 01/18/2023]
Abstract
In South America there are three snake genera with predominantly neurotoxic venoms: Crotalus, Micrurus and Hydrophis, which include nine species/subspecies, 97 species and a single marine species, respectively. Although accidents with neurotoxic venoms are less frequent than those with anticoagulant, cytotoxic or necrotic venoms (e.g. from Bothrops), they are of major public health importance. Venoms from genus Crotalus have been extensively studied, while data on the venoms from the other two genera are very limited, especially for Hydrophis. The venoms of North and South American Crotalus species show biochemical and physiopathological differences. The former species cause bothrops-like envenomation symptoms, while the latter mainly have neurotoxic and myotoxic effects, leading to respiratory paralysis and, occasionally, renal failure by myoglobinuria and death, often with no local lesions. Micrurus and Hydrophis also cause neurotoxic envenomations. Many studies have isolated, identified and characterized new enzymes and toxins, thus expanding the knowledge of snake venom composition. The present review summarizes the currently available information on neurotoxic venoms from South American snakes, with a focus on protein composition and toxicological properties. It also includes some comments concerning potential medical applications of elapid and crotalic toxins.
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Affiliation(s)
- Federico G Baudou
- Universidad Nacional de Luján (UNLu), Depto. de Ciencias Básicas, Luján, Buenos Aires, Argentina; Laboratorio de Inmunología, Instituto de Ecología y Desarrollo Sustentable (INEDES), UNLu-CONICET, Luján, Buenos Aires, Argentina.
| | - Juan P Rodriguez
- Laboratorio de Investigaciones Bioquímicas de la Facultad de Medicina (LIBIM), Instituto de Química Básica y Aplicada del Nordeste Argentino (IQUIBA-NEA), Universidad Nacional del Nordeste, Consejo Nacional de Investigaciones Científicas y Técnicas (UNNE-CONICET), Corrientes, Argentina
| | - Luciano Fusco
- Laboratorio de Investigación en Proteínas (LabInPro), IQUIBA-NEA (UNNE, CONICET), FaCENA, (UNNE), Corrientes, Argentina
| | - Adolfo R de Roodt
- Área Investigación y Desarrollo-Venenos, Instituto Nacional de Producción de Biológicos, Administración Nacional de Laboratorios e Institutos de Salud "Dr. Carlos G. Malbrán", Ministerio de Salud de la Nación, Argentina; Primera Cátedra de Toxicología, Facultad de Medicina, Universidad de Buenos Aires, Argentina; Laboratorio de Toxinopatología, Centro de Patología Experimental y Aplicada, Facultad de Medicina, Universidad de Buenos Aires, Argentina
| | - Mauricio C De Marzi
- Universidad Nacional de Luján (UNLu), Depto. de Ciencias Básicas, Luján, Buenos Aires, Argentina; Laboratorio de Inmunología, Instituto de Ecología y Desarrollo Sustentable (INEDES), UNLu-CONICET, Luján, Buenos Aires, Argentina
| | - Laura Leiva
- Laboratorio de Investigación en Proteínas (LabInPro), IQUIBA-NEA (UNNE, CONICET), FaCENA, (UNNE), Corrientes, Argentina
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Rafael de Roodt A, Lanari LC, Ramírez JE, Gómez C, Barragán J, Litwin S, Henriët van Grootheest J, Desio M, Dokmetjian JC, Dolab JA, Damin CF, Alagón A. Cross-reactivity of some Micrurus venoms against experimental and therapeutic anti-Micrurus antivenoms. Toxicon 2021; 200:153-164. [PMID: 34303716 DOI: 10.1016/j.toxicon.2021.07.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Revised: 06/25/2021] [Accepted: 07/15/2021] [Indexed: 01/22/2023]
Abstract
We developed experimental equine polyvalent and monovalent antivenoms against the venoms of Micrurus (M.) fulvius, M. nigrocinctus and M. surinamensis and studied their immunochemical reactivity on the venoms used as immunogens and on M. pyrrhocryptus, M altirostris and M. balyocoriphus venoms. Assessment of the neutralizing capacity of the polyvalent experimental antivenom was based on inhibition of lethality (preincubation and rescue assay experiments in mice) and indirect hemolytic and phospholipase activities. The immunochemical reactivity and neutralizing capacity were compared with those of two therapeutic antivenoms used for the treatment of coral snake envenomation in North America and in Argentina. In general, the experimental antivenom conferred a comparable level of neutralization against the venoms used as immunogens when compared to the therapeutic antivenoms and a certain level of cross-neutralization against the other venoms. The results suggest the need for additional venoms in the immunogenic mixture used, in order to obtain a broad spectrum anti-Micrurus antivenom with a good neutralizing potency. Paraspecific neutralization of South American coral snake venoms, although present at a higher level than the neutralization conferred by available nonspecific Micrurus therapeutic antivenoms, was rather low in relation to the specific neutralizing capacity.
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Affiliation(s)
- Adolfo Rafael de Roodt
- Instituto Nacional de Producción de Biológicos, ANLIS "Dr. Carlos G. Malbrán", Ministerio de Salud, Buenos Aires, Argentina; Primera Cátedra de Toxicología, Facultad de Medicina, Universidad de Buenos Aires, Argentina.
| | - Laura Cecilia Lanari
- Instituto Nacional de Producción de Biológicos, ANLIS "Dr. Carlos G. Malbrán", Ministerio de Salud, Buenos Aires, Argentina
| | | | - Carlos Gómez
- Cátedra de Inmunología, Facultad de Ciencias Veterinarias de la Universidad Nacional de La Plata, Argentina
| | - Javier Barragán
- Cátedra de Inmunología, Facultad de Ciencias Veterinarias de la Universidad Nacional de La Plata, Argentina
| | - Silvana Litwin
- Instituto Nacional de Producción de Biológicos, ANLIS "Dr. Carlos G. Malbrán", Ministerio de Salud, Buenos Aires, Argentina
| | - Jantine Henriët van Grootheest
- Instituto Nacional de Producción de Biológicos, ANLIS "Dr. Carlos G. Malbrán", Ministerio de Salud, Buenos Aires, Argentina
| | - Marcela Desio
- Instituto Nacional de Producción de Biológicos, ANLIS "Dr. Carlos G. Malbrán", Ministerio de Salud, Buenos Aires, Argentina
| | - José Christian Dokmetjian
- Instituto Nacional de Producción de Biológicos, ANLIS "Dr. Carlos G. Malbrán", Ministerio de Salud, Buenos Aires, Argentina
| | - Jorge Adrián Dolab
- Instituto Nacional de Producción de Biológicos, ANLIS "Dr. Carlos G. Malbrán", Ministerio de Salud, Buenos Aires, Argentina
| | - Carlos Fabián Damin
- Primera Cátedra de Toxicología, Facultad de Medicina, Universidad de Buenos Aires, Argentina
| | - Alejandro Alagón
- Instituto de Biotecnología de la Universidad Nacional Autónoma de México, Cuernavaca, Morelos, Mexico
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Maxwell K, Fraser B, Schaer M, Allen A. A retrospective evaluation of eastern coral snake envenomation and antivenom administration in cats: 30 cases (2012-2019). Toxicon 2020; 191:38-43. [PMID: 33316296 DOI: 10.1016/j.toxicon.2020.11.177] [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: 06/04/2020] [Revised: 11/19/2020] [Accepted: 11/30/2020] [Indexed: 10/22/2022]
Abstract
Thirty cats were identified to be have been suspected to have a potential coral snake envenomation after searching medical records from 2012 to 2019 at a university teaching hospital. The records were reviewed and evaluated for signalment, date and time of the snake encounter, elapsed time between encounter and hospital examination, presenting complaint, initial physical examination findings, initial laboratory findings, antivenom dose and duration of administration, adverse reactions to antivenom, additional treatments administered, progression of clinical signs, length of hospitalization, and outcome. Thirteen cats presented with clinical signs consistent with envenomation while 17 cats were treated for possible asymptomatic envenomation, as defined by the owner discovering a live or dead coral snake in their home or on their property. Initial physical examination findings included tachypnea with short shallow breaths and use of accessory muscles; tetraparesis with normal or decreased to absent spinal reflexes; cranial nerve deficits including decreased to absent gag, slow pupillary light reflexes, and absent physiologic nystagmus; and normal or altered mentation. Laboratory findings included hypercapnia, hyperglycemia, hypokalemia, increased aspartate aminotransferase activity, increased alanine aminotransferase activity, echinocytosis, leukocytosis, azotemia, and hyperlactatemia. Twenty-eight cats received antivenom; two cats received two vials while twenty-six cats received one vial. Antivenom reaction was suspected in one cat that developed facial swelling during administration of the drug. Average length of hospitalization was 1 day for cats without clinical signs and 3 days for cats with clinical signs. Twenty-nine cats survived to discharge. Due to the inclusion criteria of the study, cats euthanized on presentation or discharged without receiving antivenom may have been unintentionally excluded from the study. Diagnosis of eastern coral snake envenomation should be suspected in the cat that has acute onset of lower motor neuron neuropathy. Prognosis with treatment is considered good with 97% of cats surviving to discharge. Antivenom reaction occurred in 3.5% of administrations with none being fatal. Monitoring of hypercapnia was critical in making the decision to mechanically ventilate patients. Supportive care that includes antivenom administration, recumbency care, and mechanical ventilation if needed are the mainstays of therapy.
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Affiliation(s)
- Kathleen Maxwell
- University of Florida Small Animal Hospital, 2089 Southwest 16th Avenue, Gainesville, FL, 32608, United States.
| | - Brittney Fraser
- University of Florida Small Animal Hospital, 2089 Southwest 16th Avenue, Gainesville, FL, 32608, United States.
| | - Michael Schaer
- University of Florida Small Animal Hospital, 2089 Southwest 16th Avenue, Gainesville, FL, 32608, United States.
| | - Ashley Allen
- University of Florida Small Animal Hospital, 2089 Southwest 16th Avenue, Gainesville, FL, 32608, United States.
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Bisneto PF, Araújo BDS, Pereira HDS, Mendonça da Silva I, Sachett JDAG, Bernarde PS, Monteiro WM, Kaefer IL. Envenomations by coral snakes in an Amazonian metropolis: Ecological, epidemiological and clinical aspects. Toxicon 2020; 185:193-202. [PMID: 32710896 DOI: 10.1016/j.toxicon.2020.07.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2020] [Revised: 07/10/2020] [Accepted: 07/12/2020] [Indexed: 10/23/2022]
Abstract
Envenomation by coral snakes represents a little known burden in Brazilian Amazonia. So far, details on clinical and epidemiological aspects remain obscure in the region. We gathered data from medical charts and from the scientific collection of snakes from Fundação de Medicina Tropical Doutor Heitor Vieira Dourado, finding 26 cases of envenomation by five species of Micrurus in Manaus region, between 1987 and 2018. They represent 0.7% of the snakebites treated in the hospital since the records began, in 1979. Micrurus lemniscatus was responsible for most of the bites (10), followed by M. hemprichii (five), M. spixii (three), M. surinamensis (three) and M. averyi (one). There was no difference between the sexes of the snakes that caused bites. Patients were mostly males, and most of the cases were reported in urban areas. Bites predominated in dry season, and there was a clear geographical segregation among species. We describe seven cases of envenomation, three mild and four severe, all of which evolved to cure. Paresthesia (six), pain (five) and edema (four) were the most common local symptoms. Systemic features such as dyspnea/shallow breath (four), palpebral ptosis (four), blurred vision (three), dysarthria (three) and difficulty to walk (three) were also detected. Two patients bitten by Micrurus sp. and M. hemprichii, showed slight increased serum levels of creatine kinase (reference level <190 U/L), 1184 U/L and 1229 U/L, respectively, indicative of mild systemic myotoxicity. This is the first report of myotoxic manifestation in the envenomation by M. hemprichii. No patient developed respiratory failure, though one bitten by an adult M. spixii required intubation and mechanical ventilation due to decreased level of consciousness during evolution, probably related to induced sedation caused by concurrent alcohol intoxication. All patients were treated with Brazilian Micrurus antivenom (soro antielapídico, median = 10 vials). Six patients were pretreated intravenously with H1 and H2 antagonists and steroids, with two patients developing early adverse reactions. The median length of hospital stay was four days. Envenomations by coral snakes in Manaus region are clinically severe, but rare and sparsely distributed over time, making the detection of epidemiological and clinical patterns a challenge for public health.
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Affiliation(s)
- Pedro Ferreira Bisneto
- Universidade Federal do Amazonas - UFAM, Instituto de Ciências Biológicas, Programa de Pós-Graduação em Zoologia, Av. General Rodrigo Octavio, 1200, Coroado I, 69067-005, Manaus, Amazonas, Brazil.
| | - Bruno Dos Santos Araújo
- Faculdade Estácio do Amazonas, Av. Constantino Nery, 3693, Chapada, 69050-001, Manaus, Amazonas, Brazil
| | | | - Iran Mendonça da Silva
- Universidade do Estado do Amazonas - UEA, Escola Superior de Ciências da Saúde, Programa de Pós-Graduação em Medicina Tropical, Av. Carvalho Leal, 1777, Cachoeirinha, 69065-001, Manaus, Amazonas, Brazil; Fundação de Medicina Tropical Dr. Heitor Vieira Dourado - FMT-HVD, Diretoria de Ensino e Pesquisa, Av. Pedro Teixeira, 25, Dom Pedro, 69040-000, Manaus, Amazonas, Brazil
| | - Jacqueline de Almeida Gonçalves Sachett
- Universidade do Estado do Amazonas - UEA, Escola Superior de Ciências da Saúde, Programa de Pós-Graduação em Medicina Tropical, Av. Carvalho Leal, 1777, Cachoeirinha, 69065-001, Manaus, Amazonas, Brazil; Fundação Alfredo da Matta - FUAM, Diretoria de Ensino e Pesquisa, Av. Codajás, 24, Cachoeirinha, 69065-130, Manaus, Amazonas, Brazil
| | - Paulo Sérgio Bernarde
- Universidade Federal do Acre - UFAC, Laboratório de Herpetologia, Centro Multidisciplinar, Campus Floresta, Estrada do Canela Fina, Km 12, 69980-000, Cruzeiro do Sul, Acre, Brazil
| | - Wuelton Marcelo Monteiro
- Universidade do Estado do Amazonas - UEA, Escola Superior de Ciências da Saúde, Programa de Pós-Graduação em Medicina Tropical, Av. Carvalho Leal, 1777, Cachoeirinha, 69065-001, Manaus, Amazonas, Brazil; Fundação de Medicina Tropical Dr. Heitor Vieira Dourado - FMT-HVD, Diretoria de Ensino e Pesquisa, Av. Pedro Teixeira, 25, Dom Pedro, 69040-000, Manaus, Amazonas, Brazil
| | - Igor Luis Kaefer
- Universidade Federal do Amazonas - UFAM, Instituto de Ciências Biológicas, Programa de Pós-Graduação em Zoologia, Av. General Rodrigo Octavio, 1200, Coroado I, 69067-005, Manaus, Amazonas, Brazil
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de Castro KLP, Lopes-de-Souza L, de Oliveira D, Machado-de-Ávila RA, Paiva ALB, de Freitas CF, Ho PL, Chávez-Olórtegui C, Guerra-Duarte C. A Combined Strategy to Improve the Development of a Coral Antivenom Against Micrurus spp. Front Immunol 2019; 10:2422. [PMID: 31695693 PMCID: PMC6816313 DOI: 10.3389/fimmu.2019.02422] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Accepted: 09/27/2019] [Indexed: 01/08/2023] Open
Abstract
Accidents involving Micrurus snakes are not the most common ones but are noteworthy due to their severity. Victims envenomed by Micrurus snakes are at high risk of death and therefore must be treated with coral antivenom. In Brazil, the immunization mixture used to fabricate coral antivenom contains Micrurus frontalis and Micrurus corallinus venoms, which are difficult to be obtained in adequate amounts. Different approaches to solve the venom limitation problem have been attempted, including the use of synthetic and recombinant antigens as substitutes. The present work proposes a combined immunization protocol, using priming doses of M. frontalis venom and booster doses of synthetic B-cell epitopes derived from M. corallinus toxins (four three-finger toxins-3FTX; and one phospholipase A2-PLA2) to obtain coral antivenom in a rabbit model. Immunized animals elicited a humoral response against both M. frontalis and M. corallinus venoms, as detected by sera reactivity in ELISA and Western Blot. Relevant cross-reactivity of the obtained sera with other Micrurus species (Micrurus altirostris, Micrurus lemniscatus, Micrurus spixii, Micrurus surinamensis) venoms was also observed. The elicited antibodies were able to neutralize PLA2 activity of both M. frontalis and M. corallinus venoms. In vivo, immunized rabbit sera completely protected mice from a challenge with 1.5 median lethal dose (LD50) of M. corallinus venom and 50% of mice challenged with 1.5 LD50 of M. frontalis venom. These results show that this combined protocol may be a suitable alternative to reduce the amount of venom used in coral antivenom production in Brazil.
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Affiliation(s)
| | - Letícia Lopes-de-Souza
- Departamento de Bioquímica, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | | | | | | | | | | | - Carlos Chávez-Olórtegui
- Departamento de Bioquímica, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
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Akcali CK, Pérez-Mendoza HA, Kikuchi DW, Pfennig DW. Multiple models generate a geographical mosaic of resemblance in a Batesian mimicry complex. Proc Biol Sci 2019; 286:20191519. [PMID: 31530146 PMCID: PMC6784714 DOI: 10.1098/rspb.2019.1519] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Accepted: 08/22/2019] [Indexed: 11/12/2022] Open
Abstract
Batesian mimics-benign species that receive protection from predation by resembling a dangerous species-often occur with multiple model species. Here, we examine whether geographical variation in the number of local models generates geographical variation in mimic-model resemblance. In areas with multiple models, selection might be relaxed or even favour imprecise mimicry relative to areas with only one model. We test the prediction that model-mimic match should vary with the number of other model species in a broadly distributed snake mimicry complex where a mimic and a model co-occur both with and without other model species. We found that the mimic resembled its model more closely when they were exclusively sympatric than when they were sympatric with other model species. Moreover, in regions with multiple models, mimic-model resemblance was positively correlated with the resemblance between the model and other model species. However, contrary to predictions, free-ranging natural predators did not attack artificial replicas of imprecise mimics more often when only a single model was present. Taken together, our results suggest that multiple models might generate a geographical mosaic in the degree of phenotype matching between Batesian mimics and their models.
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Affiliation(s)
- Christopher K. Akcali
- Department of Biology, University of North Carolina, Chapel Hill, NC, USA
- North Carolina Museum of Natural Sciences, Raleigh, NC, USA
| | - Hibraim Adán Pérez-Mendoza
- Laboratorio de Ecología Evolutiva y Conservación de Anfibios y Reptiles, Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de Mexico, Tlalneplanta, Mexico
| | - David W. Kikuchi
- Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, AZ, USA
| | - David W. Pfennig
- Department of Biology, University of North Carolina, Chapel Hill, NC, USA
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Onary S, Rincón AD, Hsiou AS. Fossil snakes (Squamata, Serpentes) from the tar pits of Venezuela: taxonomic, palaeoenvironmental, and palaeobiogeographical implications for the North of South America during the Cenozoic/Quaternary boundary. PeerJ 2018; 6:e5402. [PMID: 30128192 PMCID: PMC6097493 DOI: 10.7717/peerj.5402] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2018] [Accepted: 07/18/2018] [Indexed: 11/20/2022] Open
Abstract
Background Tar seep deposits in South America historically are well-known for their rich record of fossil mammals, contrasting with only a few formal reports of reptile remains. Here we report a new snake fauna recovered from two tar pits from Venezuela. The fossil remains come from two localities: (a) El Breal de Orocual, which comprises an inactive tar seep estimated to be Plio/Pleistocene in age; and (b) Mene de Inciarte, an active surface asphalt deposit with an absolute age dating to the late Pleistocene. Methods The taxonomic identity of all specimens was assessed via consultation of the relevant literature and comparison with extant specimens. The taxonomic assignments are supported by detailed anatomical description. Results The Mene de Inciarte snake fauna comprises vertebral remains identified as the genus Epicrates sp. (Boidae), indeterminate viperids, and several isolated vertebrae attributable to "Colubridae" (Colubroidea, sensu Zaher et al., 2009). Amongst the vertebral assemblage at El Breal de Orocual, one specimen is assigned to the genus Corallus sp. (Boidae), another to cf. Micrurus (Elapidae), and several others to "Colubrids" (Colubroides, sensu Zaher et al., 2009) and the Viperidae family. Conclusions These new records provide valuable insight into the diversity of snakes in the north of South America during the Neogene/Quaternary boundary. The snake fauna of El Breal de Orocual and Mene de Inciarte demonstrates the presence of Boidae, Viperidae, "colubrids", and the oldest South American record of Elapidae. The presence of Corallus, Epicrates, and viperids corroborates the mosaic palaeoenvironmental conditions of El Breal de Orocual. The presence of Colubroides within both deposits sheds light on the palaeobiogeographical pattern of caenophidians snake colonization of South America and is consistent with the hypothesis of two episodes of dispersion of Colubroides to the continent.
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Affiliation(s)
- Silvio Onary
- Departamento de Biologia, Laboratório de Paleontologia de Ribeirão Preto, Faculdade de Filosofia Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Ascanio D Rincón
- Centro de Ecología, Laboratório de Paleontología, Instituto Venezolano de Investigaciones Científicas, Caracas, Venezuela
| | - Annie S Hsiou
- Departamento de Biologia, Laboratório de Paleontologia de Ribeirão Preto, Faculdade de Filosofia Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, São Paulo, Brazil
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de la Rosa G, Corrales-García LL, Rodriguez-Ruiz X, López-Vera E, Corzo G. Short-chain consensus alpha-neurotoxin: a synthetic 60-mer peptide with generic traits and enhanced immunogenic properties. Amino Acids 2018; 50:885-895. [PMID: 29626299 DOI: 10.1007/s00726-018-2556-0] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [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: 01/29/2018] [Accepted: 03/13/2018] [Indexed: 10/17/2022]
Abstract
The three-fingered toxin family and more precisely short-chain α-neurotoxins (also known as Type I α-neurotoxins) are crucial in defining the elapid envenomation process, but paradoxically, they are barely neutralized by current elapid snake antivenoms. This work has been focused on the primary structural identity among Type I neurotoxins in order to create a consensus short-chain α-neurotoxin with conserved characteristics. A multiple sequence alignment considering the twelve most toxic short-chain α-neurotoxins reported from the venoms of the elapid genera Acanthophis, Oxyuranus, Walterinnesia, Naja, Dendroaspis and Micrurus led us to propose a short-chain consensus α-neurotoxin, here named ScNtx. The synthetic ScNtx gene was de novo constructed and cloned into the expression vector pQE30 containing a 6His-Tag and an FXa proteolytic cleavage region. Escherichia coli Origami cells transfected with the pQE30/ScNtx vector expressed the recombinant consensus neurotoxin in a soluble form with a yield of 1.5 mg/L of culture medium. The 60-amino acid residue ScNtx contains canonical structural motifs similar to α-neurotoxins from African elapids and its LD50 of 3.8 µg/mice is similar to the most toxic short-chain α-neurotoxins reported from elapid venoms. Furthermore, ScNtx was also able to antagonize muscular, but not neuronal, nicotinic acetylcholine receptors (nAChR). Rabbits immunized with ScNtx were able to immune-recognize short-chain α-neurotoxins within whole elapid venoms. Type I neurotoxins are difficult to isolate and purify from natural sources; therefore, the heterologous expression of molecules such ScNtx, bearing crucial motifs and key amino acids, is a step forward to create common immunogens for developing cost-effective antivenoms with a wider spectrum of efficacy, quality and strong therapeutic value.
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Affiliation(s)
- Guillermo de la Rosa
- Departamento de Medicina Molecular y Bioprocesos, Instituto de Biotecnología, Universidad Nacional Autónoma de México, UNAM, Apartado Postal 510-3, 61500, Cuernavaca, Morelos, Mexico
| | - Ligia L Corrales-García
- Departamento de Medicina Molecular y Bioprocesos, Instituto de Biotecnología, Universidad Nacional Autónoma de México, UNAM, Apartado Postal 510-3, 61500, Cuernavaca, Morelos, Mexico.,Departamento de Alimentos, Facultad de Ciencias Farmacéuticas y Alimentarias, Universidad de Antioquia, AA 1226, Medellín, Colombia
| | - Ximena Rodriguez-Ruiz
- Instituto de Ciencias del Mar y Limnología/Posgrado en Ciencias del Mar y Limnologia, Universidad Nacional Autónoma de México, UNAM, Circuito exterior s/n, Ciudad Universitaria, 04510, Mexico City, Mexico
| | - Estuardo López-Vera
- Instituto de Ciencias del Mar y Limnología/Posgrado en Ciencias del Mar y Limnologia, Universidad Nacional Autónoma de México, UNAM, Circuito exterior s/n, Ciudad Universitaria, 04510, Mexico City, Mexico
| | - Gerardo Corzo
- Departamento de Medicina Molecular y Bioprocesos, Instituto de Biotecnología, Universidad Nacional Autónoma de México, UNAM, Apartado Postal 510-3, 61500, Cuernavaca, Morelos, Mexico. .,Institute of Biotechnology-UNAM, Av. Universidad 2001, 62210, Cuernavaca, Morelos, Mexico.
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Dashevsky D, Fry BG. Ancient Diversification of Three-Finger Toxins in Micrurus Coral Snakes. J Mol Evol 2018; 86:58-67. [PMID: 29379986 DOI: 10.1007/s00239-017-9825-5] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Accepted: 12/18/2017] [Indexed: 01/03/2023]
Abstract
Coral snakes, most notably the genus Micrurus, are the only terrestrial elapid snakes in the Americas. Elapid venoms are generally known for their potent neurotoxicity which is usually caused by Three-Finger Toxin (3FTx) proteins. These toxins can have a wide array of functions that have been characterized from the venom of other elapids. We examined publicly available sequences from Micrurus 3FTx to show that they belong to 8 monophyletic clades that diverged as deep in the 3FTx phylogenetic tree as the other clades with characterized functions. Functional residues from previously characterized clades of 3FTx are not well conserved in most of the Micrurus toxin clades. We also analyzed the patterns of selection on these toxins and find that they have been diversifying at different rates, with some having undergone extreme diversifying selection. This suggests that Micrurus 3FTx may contain a previously underappreciated functional diversity that has implications for the clinical outcomes of bite victims, the evolution and ecology of the genus, as well as the potential for biodiscovery efforts focusing on these toxins.
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Akcali CK, Pfennig DW. Geographic variation in mimetic precision among different species of coral snake mimics. J Evol Biol 2017; 30:1420-1428. [PMID: 28425157 DOI: 10.1111/jeb.13094] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [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: 01/26/2017] [Accepted: 04/03/2017] [Indexed: 11/27/2022]
Abstract
Batesian mimicry is widespread, but whether and why different species of mimics vary geographically in resemblance to their model is unclear. We characterized geographic variation in mimetic precision among four Batesian mimics of coral snakes. Each mimic occurs where its model is abundant (i.e. in 'deep sympatry'), rare (i.e. at the sympatry/allopatry boundary or 'edge sympatry') and absent (i.e. in allopatry). Geographic variation in mimetic precision was qualitatively different among these mimics. In one mimic, the most precise individuals occurred in edge sympatry; in another, they occurred in deep sympatry; in the third, they occurred in allopatry; and in the fourth, precise mimics were not concentrated anywhere throughout their range. Mimicry was less precise in allopatry than in sympatry in only two mimics. We present several nonmutually exclusive hypotheses for these patterns. Generally, examining geographic variation in mimetic precision - within and among different mimics - offers novel insights into the causes and consequences of mimicry.
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Affiliation(s)
- C K Akcali
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.,North Carolina Museum of Natural Sciences, Raleigh, NC, USA
| | - D W Pfennig
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
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13
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Aird SD, da Silva NJ, Qiu L, Villar-Briones A, Saddi VA, Pires de Campos Telles M, Grau ML, Mikheyev AS. Coralsnake Venomics: Analyses of Venom Gland Transcriptomes and Proteomes of Six Brazilian Taxa. Toxins (Basel) 2017; 9:toxins9060187. [PMID: 28594382 PMCID: PMC5488037 DOI: 10.3390/toxins9060187] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [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: 03/18/2017] [Revised: 05/31/2017] [Accepted: 06/02/2017] [Indexed: 11/16/2022] Open
Abstract
Venom gland transcriptomes and proteomes of six Micrurus taxa (M. corallinus, M. lemniscatus carvalhoi, M. lemniscatus lemniscatus, M. paraensis, M. spixii spixii, and M. surinamensis) were investigated, providing the most comprehensive, quantitative data on Micrurus venom composition to date, and more than tripling the number of Micrurus venom protein sequences previously available. The six venomes differ dramatically. All are dominated by 2-6 toxin classes that account for 91-99% of the toxin transcripts. The M. s. spixii venome is compositionally the simplest. In it, three-finger toxins (3FTxs) and phospholipases A₂ (PLA₂s) comprise >99% of the toxin transcripts, which include only four additional toxin families at levels ≥0.1%. Micrurus l. lemniscatus venom is the most complex, with at least 17 toxin families. However, in each venome, multiple structural subclasses of 3FTXs and PLA₂s are present. These almost certainly differ in pharmacology as well. All venoms also contain phospholipase B and vascular endothelial growth factors. Minor components (0.1-2.0%) are found in all venoms except that of M. s. spixii. Other toxin families are present in all six venoms at trace levels (<0.005%). Minor and trace venom components differ in each venom. Numerous novel toxin chemistries include 3FTxs with previously unknown 8- and 10-cysteine arrangements, resulting in new 3D structures and target specificities. 9-cysteine toxins raise the possibility of covalent, homodimeric 3FTxs or heterodimeric toxins with unknown pharmacologies. Probable muscarinic sequences may be reptile-specific homologs that promote hypotension via vascular mAChRs. The first complete sequences are presented for 3FTxs putatively responsible for liberating glutamate from rat brain synaptosomes. Micrurus C-type lectin-like proteins may have 6-9 cysteine residues and may be monomers, or homo- or heterodimers of unknown pharmacology. Novel KSPIs, 3× longer than any seen previously, appear to have arisen in three species by gene duplication and fusion. Four species have transcripts homologous to the nociceptive toxin, (MitTx) α-subunit, but all six species had homologs to the β-subunit. The first non-neurotoxic, non-catalytic elapid phospholipase A₂s are reported. All are probably myonecrotic. Phylogenetic analysis indicates that the six taxa diverged 15-35 million years ago and that they split from their last common ancestor with Old World elapines nearly 55 million years ago. Given their early diversification, many cryptic micrurine taxa are anticipated.
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Affiliation(s)
- Steven D Aird
- Division of Faculty Affairs, Okinawa Institute of Science and Technology Graduate University, 1919-1 Tancha, Onna-son, Kunigami-gun, Okinawa-ken 904-0495, Japan.
- Ecology and Evolution Unit, Okinawa Institute of Science and Technology Graduate University, 1919-1 Tancha, Onna-son, Kunigami-gun, Okinawa-ken 904-0495, Japan.
| | - Nelson Jorge da Silva
- Programa de Pós-Graduação em Ciências Ambientais e Saúde, Pontifícia Universidade Católica de Goiás, Goiânia, Goiás 74605-140, Brazil.
| | - Lijun Qiu
- Ecology and Evolution Unit, Okinawa Institute of Science and Technology Graduate University, 1919-1 Tancha, Onna-son, Kunigami-gun, Okinawa-ken 904-0495, Japan.
| | - Alejandro Villar-Briones
- Research Support Division, Okinawa Institute of Science and Technology Graduate University, 1919-1 Tancha, Onna-son, Kunigami-gun, Okinawa-ken 904-0495, Japan.
| | - Vera Aparecida Saddi
- Programa de Pós-Graduação em Ciências Ambientais e Saúde, Pontifícia Universidade Católica de Goiás, Goiânia, Goiás 74605-140, Brazil.
- Laboratório de Oncogenética e Radiobiologia da Associação de Combate ao Câncer em Goiás, Universidade Federal de Goiás, Rua 239 no. 52-Setor Universitário, Goiânia, Goiás 74065-070, Brazil.
| | - Mariana Pires de Campos Telles
- Programa de Pós-Graduação em Ciências Ambientais e Saúde, Pontifícia Universidade Católica de Goiás, Goiânia, Goiás 74605-140, Brazil.
- Laboratório de Genética & Biodiversidade, Universidade Federal de Goiás, Goiânia, Goiás 74690-900, Brazil.
| | - Miguel L Grau
- Ecology and Evolution Unit, Okinawa Institute of Science and Technology Graduate University, 1919-1 Tancha, Onna-son, Kunigami-gun, Okinawa-ken 904-0495, Japan.
| | - Alexander S Mikheyev
- Ecology and Evolution Unit, Okinawa Institute of Science and Technology Graduate University, 1919-1 Tancha, Onna-son, Kunigami-gun, Okinawa-ken 904-0495, Japan.
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Lomonte B, Sasa M, Rey-Suárez P, Bryan W, Gutiérrez JM. Venom of the Coral Snake Micrurus clarki: Proteomic Profile, Toxicity, Immunological Cross-Neutralization, and Characterization of a Three-Finger Toxin. Toxins (Basel) 2016; 8:E138. [PMID: 27164141 DOI: 10.3390/toxins8050138] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2016] [Revised: 04/25/2016] [Accepted: 05/02/2016] [Indexed: 11/16/2022] Open
Abstract
Micrurus clarki is an uncommon coral snake distributed from the Southeastern Pacific of Costa Rica to Western Colombia, for which no information on its venom could be found in the literature. Using a ‘venomics’ approach, proteins of at least nine families were identified, with a moderate predominance of three-finger toxins (3FTx; 48.2%) over phospholipase A2 (PLA2; 36.5%). Comparison of this venom profile with those of other Micrurus species suggests that it may represent a more balanced, ‘intermediate’ type within the dichotomy between 3FTx- and PLA2-predominant venoms. M. clarki venom was strongly cross-recognized and, accordingly, efficiently neutralized by an equine therapeutic antivenom against M. nigrocinctus, revealing their high antigenic similarity. Lethal activity for mice could be reproduced by a PLA2 venom fraction, but, unexpectedly, not by fractions corresponding to 3FTxs. The most abundant venom component, hereby named clarkitoxin-I, was identified as a short-chain (type I) 3FTx, devoid of lethal effect in mice, whose target remains to be defined. Its amino acid sequence of 66 residues shows high similarity with predicted sequences of venom gland transcripts described for M. fulvius, M. browni, and M. diastema.
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