Resumen Registramos la depredación de la serpiente de cascabel Crotalus helleri caliginis, endémica de la Isla Coronado Sur, Baja California, basados en el hallazgo de restos óseos de dos serpientes en las egagrópilas del Halcón peregrino Falco peregrinus. Este registro representa la primera depredación confirmada para la serpiente isleña y amplía el conocimiento de la dieta del Halcón peregrino en la isla.

Abstract We recorded the predation on the rattlesnake Crotalus helleri caliginis, endemic to Coronado Sur Island, Baja California, based on the discovery of bone remains of two snakes in the falcon pellets of the Peregrine Falcon Falco peregrinus. This record represents the first confirmed predation of the insular snake and expands our knowledge of the Peregrine Falcon diet on the island.

Abstract This study presents the first complete mitogenome of the Brazilian Atlantic bushmaster Lachesis with insights into snake evolution. The total length was 17,177 bp, consisting of 13 PCGs, 22 tRNAs, two rRNAs and a duplicate control region (CRs). Almost all genes were encoded by the heavy-strand, except for the ND6 gene and eight tRNAs (tRNA-Gln, Ala, Asn, Cys, Tyr, Ser[TGA anticodon], Glu, Pro). Only ATG, ATA, and ATC were starting codons for protein-coding sequences. Stop codons mainly were TAA, AGA, AGG, and TAG; whereas ND1, ND3, and CYTB terminated with incomplete stop codons. Phylogeny retrieved Lachesis within the Crotalinae as the sister group of Agkistrodon; and the Lachesis+Agkistrodon clade as the sister group of (Sistrurus+Crotalus)+Bothrops. The tree supports Crotalinae, Viperinae, and Azemiopinae in the Viperidae family, being sister taxa of Colubridae+(Elapidae+Psammophiidae). The mean genetic distance across 15 snake families and 57 nucleotide sequences was 0.37. The overall mean value of genetic distance across the Crotalinae was 0.23, with Lachesis muta exhibiting the shortest distance of 0.2 with Agkistrodon piscivorus, Protobothrops dabieshanensis and P. flavoviridis and the greatest 0.25 with Gloydius blomhoffii, Trimeresurus albolabris, S. miliarius, and Deinagkistrodon acutus. The complete Atlantic L. muta mitogenome presented herein is only the third annotated mitogenome from more than 430 described Brazilian snake species.

Abstract Snakebite envenoming is a major global health problem that kills or disables half a million people in the world’s poorest countries. Identifying the biting snake and its habitat use is key to understanding snakebite eco-epidemiology and optimizing its clinical management. To prevent and combat the neglected snakebite disease, we characterize the morphology, geographic distribution, habitat use, and snakebites of medically important venomous snakes in the state of Rio de Janeiro (Brazil). Despite Philodryas spp. not being considered of medical importance by the Brazilian Ministry of Health, we also explore their data once the bites may require medical intervention, may cause death, and their consequences are underestimated. Methods: We assessed taxonomy and geographic data from specimens housed in scientific collections, the literature, and the Notifiable Diseases Information System. Our data revealed fragility in the morphological characters recommended to distinguish Bothrops jararaca from B. jararacussu, identify the subspecies of Crotalus durissus and distinguish the species of Philodryas. To help identify these species, we present an identification key to the venomous snake species from Rio de Janeiro based on the morphological data collected. We record the genera Bothrops and Micrurus in all mesoregions of the state. Here, we provide the first record of C. durissus in the Serrana region, supporting the hypothesis of geographic expansion of the species in the state. The crotalic antivenom must not be missing in Médio Paraíba, Centro-Sul Fluminense, and Serrana, where the rattlesnake C. durissus occurs. Bothrops bilineatus and Lachesis muta have historical records presented for the first time herein. However, these species are likely endangered or extinct in the state. There were 7,483 snakebites reported between 2001 and 2019, with an annual average of 393.8 cases. The Bothrops genus is responsible for the majority of accidents. The highest number of cases occurred in the Serrana region, the largest pole of family agriculture in Rio de Janeiro. We improve the identification of venomous snake species, better delimit their distribution, and update the number of cases of snakebites, thus providing greater precision in the attention to this problem in Rio de Janeiro. We emphasize the importance of clinical studies to test using bothropic-crotalic antivenom and heparin in all mesoregions to treat B. jararacussu envenomation; and mechanical ventilation, atropine, and anticholinesterases in the emergency health centers in the Metropolitana and Norte Fluminense regions due to the occurrence of the coral M. lemniscatus in these areas.

Resumo O envenenamento com serpentes de importância médica é um grande problema de saúde global que mata ou incapacita meio milhão de pessoas nos países mais pobres do mundo. A identificação de serpentes de importância médica e aspectos de sua história de vida é fundamental para compreender a eco-epidemiologia dos acidentes ofídicos e otimizar seu manejo clínico. Para prevenir e combater a doença negligenciada do ofidismo, caracterizamos os dados de morfologia, distribuição, uso de habitat e acidentes ofídicos das serpentes peçonhentas de importância médica no estado do Rio de Janeiro, Brasil. Apesar de Philodryas spp. não serem consideradas de importância médica pelo Ministério da Saúde do Brasil, também apresentamos seus dados porque suas picadas podem exigir intervenção médica, causar morte e suas consequências são subestimadas. Foram avaliados dados morfológicos e de habitat de espécimes pertencentes a coleções cientificas, literatura e dados do Sistema de Informação de Agravos de Notificação. Nossos dados revelaram caracteres morfológicos frágeis recomendados para distinguir Bothrops jararaca e B. jararacussu, para identificar as subespécies de cascavel Crotalus durissus e para distinguir as serpentes cipó Philodryas spp. Para auxiliar na identificação dessas espécies apresentamos uma chave de identificação para as mesmas com base nos dados morfológicos coletados. Registramos os gêneros Bothrops e Micrurus em todas as mesorregiões do estado. Já o soro anticrotálico não pode faltar no Médio Paraíba, Centro-Sul Fluminense e Serrana, onde encontramos a cascavel Crotalus durissus. Aqui estendemos o registro da cascavel pela primeira vez para a região Serrana, corroborando a hipótese da expansão da espécie no estado. Bothrops bilineatus e Lachesis muta possuem registros históricos aqui apresentados pela primeira vez. Essas espécies provavelmente estão ameaçadas ou extintas no estado. Foram 7,483 acidentes entre 2001-2019, com média anual de 393.8. O gênero Bothrops é responsável pela maioria dos acidentes. O maior número de casos ocorreu na região Serrana, maior polo da agricultura familiar do Rio de Janeiro. Aperfeiçoamos a identificação das espécies de serpentes de importância médica, delimitamos melhor sua distribuição e atualizamos os acidentes ofídicos, proporcionando maior precisão na atenção ao ofidismo no estado do Rio de Janeiro. Ressaltamos a importância de estudos clínicos para testar o uso de soro antibotrópico-crotálico e heparina em todas as mesorregiões para o tratamento do ofidismo B. jararacussu e ventilação mecânica, atropina e anticolinesterásicos nos prontos-socorros das regiões Metropolitana e Norte Fluminense pela ocorrência do coral M. lemniscatus.

Abstract Bothrops alternatus (yarará grande, víbora de la cruz) is a snake belonging to the Viperidae family and is widely distributed in Argentina. In the northeast, this snake group for the majority of the snakebite accidents. There are reports about envenomation in horses with clinical signs including swelling, hemorrhage, dermo and myonecrosis at the bite sight in addition to systemic effects such as impaired blood coagulation, hemorrhage and damage to vital organs. An additional consequence in the horse is laminitis which reduces the work capacity of the survivor on a long-term basis. This occurs independent of the site where the venom was injected. laminitis induces pain and claudication, and it can evolve to deform the hoof. This study uses explants from freshly slaughtered horses as an in-vitro assay from the limbs of normal horses in order to demonstrate the ability of Bothrops snake venom to cause laminitis. Explants were incubated with whole venom and phospholipases A2 (PLA2). The objective was to reproduce laminitis in vitro to corroborate the clinical data reported in snake venom accidents. Equine laminitis induced by whole venom was characterized by damage to the lamellar dermo-epidermal junction, loosening of the lamellar basement membrane and cytotoxic effects. Epidermal basal cells showed changes in the shape and size of their nuclei and other abnormalities.

Resumen Bothrops alternatus (yarará grande, víbora de la cruz) es una serpiente perteneciente a la familia Viperidae, y se encuentra ampliamente distribuida en Argentina. En el nordeste de nuestro país, esta serpiente ocasiona el mayor número de accidentes. Existen reportes de envenenamiento en equinos, siendo sus signos y síntomas más importantes: inflamación y hemorragia, dermo y mionecrosis en el área de inoculación del veneno. Por otro lado, la acción sistémica consiste en incoagulabilidad sanguínea, hemorragia y lesiones de órganos que pueden comprometer la salud del animal. Una secuela, debida a la intoxicación por esta serpiente, es la laminitis, que afecta la capacidad de trabajo del equino, independientemente del sitio de inoculación del veneno, debido a la acción sistémica del mismo. Esta patología produce dolor, claudicación, que luego puede progresar con deformación del casco. Se efectuó un estudio in vitro, tomando como modelo experimental muestras (explantes) de pie equino. Estas fueron incubadas con veneno entero y con Fosfolipasa A2 (PLA2) del mismo veneno con el objeto de reproducir laminitis a los efectos de corroborar datos clínicos reportados en accidentes por yarará como así también proponer una metodología de estudio de laminitis en explantes de pie equino. La laminitis inducida por el veneno entero se caracterizó por la separación de la unión dermo-epidérmica, desprendimiento de membrana basal y citotoxicidad y consecuentemente desprendimiento de unión dermo-epidérmica, permaneciendo las células basales epidérmicas con alteraciones en forma y tamaño de los núcleos, entre otras anormalidades. En contraste, las muestras incubadas con PLA2, las células basales epidérmicas mostraron anomalías citoplasmáticas y nucleares, pero con separación leve de la unión dermoepidérmica y presente solo en algunas áreas de las LES.

Abstract Background Endogenous phospholipases A2 (PLA2) play a fundamental role in inflammation, neurodegenerative diseases, apoptosis and cellular senescence. Neurotoxins with PLA2 activity are found in snake venoms from the Elapidae and Viperidae families. The mechanism of action of these neurotoxins have been studied using hippocampal and cerebellar neuronal cultures showing [Ca2+]i increase, mitochondrial depolarization and cell death. Astrocytes are rarely used as a model, despite being modulators at the synapses and responsible for homeostasis and defense in the central nervous system. Preserving the cell division ability, they can be utilized to study the cell proliferation process. In the present work cultured astrocytes and glioblastoma cells were employed to characterize the action of β-micrustoxin (previously named Mlx-9), a PLA2 isolated from Micrurus lemniscatus snake venom. The β-micrustoxin structure was determined and the cell proliferation, cell cycle phases and the regulatory proteins p53, p21 and p27 were investigated. Methods β-micrustoxin was characterized biochemically by a proteomic approach. Astrocytes were obtained by dissociation of pineal glands from Wistar rats; glioblastoma tumor cells were purchased from ATCC and Sigma and cultured in DMEM medium. Cell viability was evaluated by MTT assay; cell proliferation and cell cycle phases were analyzed by flow cytometry; p53, p21 and p27 proteins were studied by western blotting and immunocytochemistry. Results Proteomic analysis revealed fragments on β-micrustoxin that aligned with a PLA2 from Micrurus lemniscatus lemniscatus previously identified as transcript ID DN112835_C3_g9_i1/m.9019. β-micrustoxin impaired the viability of astrocytes and glioblastoma tumor cells. There was a reduction in cell proliferation, an increase in G2/M phase and activation of p53, p21 and p27 proteins in astrocytes. Conclusion These findings indicate that β-micrustoxin from Micrurus lemniscatus venom could inhibit cell proliferation through p53, p21 and p27 activation thus imposing cell cycle arrest at the checkpoint G2/M.

Abstract Background: A new pit viper, Protobothrops kelomohy, has been recently discovered in northern and northwestern Thailand. Envenoming by the other Protobothrops species across several Asian countries has been a serious health problem since their venom is highly hematotoxic. However, the management of P. kelomohy bites is required as no specific antivenom is available. This study aimed to investigate the biochemical properties and proteomes of P. kelomohy venom (PKV), including the cross-neutralization to its lethality with antivenoms available in Thailand. Methods: PKV was evaluated for its neutralizing capacity (ER50), lethality (LD50), procoagulant and hemorrhagic effects with three monovalent antivenoms (TAAV, DSAV, and CRAV) and one polyvalent (HPAV) hematotoxic antivenom. The enzymatic activities were examined in comparison with venoms of Trimeresurus albolabris (TAV), Daboia siamensis (DSV), Calloselasma rhodostoma (CRV). Molecular mass was separated on SDS-PAGE, then the specific proteins were determined by western blotting. The venom protein classification was analyzed using mass spectrometry-based proteomics. Results: Intravenous LD50 of PKV was 0.67 µg/g. ER50 of HPAV, DSAV and TAAV neutralize PKV at 1.02, 0.36 and 0.12 mg/mL, respectively. PKV exhibited procoagulant effect with a minimal coagulation dose of 12.5 ± 0.016 µg/mL and hemorrhagic effect with a minimal hemorrhagic dose of 1.20 ± 0.71 µg/mouse. HPAV was significantly effective in neutralizing procoagulant and hemorrhagic effects of PKV than those of TAAV, DSAV and CRAV. All enzymatic activities among four venoms exhibited significant differences. PKV proteome revealed eleven classes of putative snake venom proteins, predominantly metalloproteinase (40.85%), serine protease (29.93%), and phospholipase A2 (15.49%). Conclusions: Enzymatic activities of PKV are similarly related to other viperid venoms in this study by quantitatively hematotoxic properties. Three major venom toxins were responsible for coagulopathy in PKV envenomation. The antivenom HPAV was considered effective in neutralizing the lethality, procoagulant and hemorrhagic effects of PKV.

Resumen La diversidad de helmintos digenéticos de serpientes del Bioma Pampa es poco conocida, con pocos registros en Brasil, Argentina y Uruguay. El presente estudio documenta especies de Digenea que parasitan serpientes en el Bioma Pampa, sur de Brasil. Se examinaron 42 individuos pertenecientes a 11 especies de Dipsadidae y Viperidae. En 50% de las serpientes analizadas se encontraron un total de 178 ejemplares pertenecientes a 9 taxones de digéneos. Los hábitats y el comportamiento del hospedador pueden influir en la fauna parasitaria de las serpientes, ya que la diversidad y abundancia de helmintos fueron mayores en los hospedadores presentes en ambientes semiacuáticos y de pastizales. Además, 89% de los tremátodos digenéticos utilizan anuros como segundos hospedadores intermediarios; según la literatura, los anuros son el recurso alimenticio más común para estas serpientes. En este contexto, los estudios de dieta y helmintofauna de serpientes son complementarios y contribuyen a la comprensión de la biología de las especies y su papel en los ecosistemas.

Abstract The diversity of digenetic helminths of snakes from the Pampa Biome is poorly known, with few records in Brazil, Argentina, and Uruguay. The present study documents species of Digenea parasitizing snakes in the Pampa Biome, southern Brazil. Forty-two individuals belonging to 11 species of Dipsadidae and Viperidae were examined. A total of 178 specimens belonging to 9 taxa of digenetic trematodes were found in 50% of the snakes analyzed. Habitats and host behavior may influence the parasite fauna of snakes, since helminth diversity and abundance were greater in hosts present in semi-aquatic and grassland environments. Further, 89% of digenetic trematodes use anurans as second intermediate hosts; according to the literature, anurans are the most common food resource for these snakes. In this context, studies of diet and helminth fauna of snakes are complementary and contribute to the understanding of the biology of species and their role in ecosystems.

RESUMO: Embora raros, os micoplasmas estão incluídos entre as causas de doenças respiratórias em répteis e, na ordem Squamata, já foram realizados três relatos destes microrganismos causando doença em pítons. Este estudo teve como objetivo avaliar a ocorrência de espécies de Mycoplasma em serpentes em cativeiro. Foram avaliadas 26 serpentes das famílias Pythonidae (13), Boidae (7), Viperidae (5) e Colubridae (1) do RioZoo, Brasil. Os animais foram examinados para determinar sinais clínicos consistentes com qualquer doença infecciosa. Amostras de swab traqueal de cobras foram coletadas em meio Frey e analisadas por isolamento microbiológico e pela técnica da PCR para identificar Mycoplasma spp. As amostras positivas para o gênero Mycoplasma spp. foram submetidas ao sequenciamento genético para identificação das espécies. No isolamento, 19,23% (5/26) foram positivos, enquanto 65,38% (17/26) dos animais foram positivos por PCR. Com base nas análises das seis sequências obtidas, houve similaridade com o Mycoplasma spp. descrito anteriormente em um píton e M. agassizii e M. testudineum encontrados em quelônios. Este é o primeiro relato de Mycoplasma spp. em animais das famílias Boidae e Viperidae. Mycoplasma spp. foi detectado em serpentes com e sem sinais clínicos. Os micoplasmas encontrados apresentaram semelhança genética com outros já descritos em répteis. Não houve relação entre a presença de Mycoplasma spp. e sinais clínicos.

ABSTRACT: Although rare, mycoplasmas are included among the causes of respiratory diseases in reptiles and, in the order Squamata, three reports of these microorganisms causing diseases in pythons have already been reported. This study aimed to evaluate the occurrence of Mycoplasma species in captive snakes. A total of 26 snakes of the families Pythonidae (13), Boidae (7), Viperidae (5) and Colubridae (1) from RioZoo, Brazil, were evaluated. Animals were examined to determine clinical signs consistent with any infectious disease. Tracheal swab samples from snakes were collected in Frey medium and analyzed for the presence of Mycoplasma spp.by isolation and a genus-specific PCR. DNA sequencing analyses of six positive samples by PCR were carried out to identify the species. Using isolation 19.23% (5/26) was positive, while 65.38% (17/26) of the animals were positive by PCR. Based on the analyses of the six sequences obtained, there was similarity with a Mycoplasma spp. previously described in a phyton and, M. agassizii and M. testudineum reported in chelonians. This is the first report of Mycoplasma spp. in animals of the families Boidae and Viperidae. Mycoplasma spp. were detected in snakes with and without clinical signs. The mycoplasmas reported resented identity (range, 95% to 100%) to others already described in reptiles. There was no relationship between the presence of Mycoplasma spp. and clinical signs.

RESUMO: No Brasil, as serpentes do gênero Bothrops são responsáveis por milhares de acidentes, e seus venenos são compostos principalmente de enzimas proteolíticas. Embora o soro antiofídico produzido pelos institutos brasileiros seja notavelmente eficiente, mais estudos são necessários, especialmente na medicina veterinária. O veneno contem enzimas e proteínas não-enzimáticas que interferem com a hemostasia levando a hemorragias ou trombose. A associação de outros tratamentos ao soro antibotrópico foi a razão para o desenvolvimento do presente estudo. O objetivo deste estudo foi avaliar as alterações da hemostasia causadas pelo veneno de Bothrops alternatus em coelhos, após tratamento com soro antibotrópico, ácido tranexâmico e desmopressina. Vinte coelhos da Nova Zelândia foram distribuídos em cinco grupos (n = 4) que foram submetidos a experimentos com 150mcg/kg de veneno de B. alternatus por injeção intramuscular. O Grupo 1 (G1) foi o controle positivo e recebeu veneno e PBS / BSA, enquanto o Grupo 2 (G2) foi tratado com ácido tranexâmico, o Grupo 3 (G3) com desmopressina, o Grupo 4 (G4) com ácido tranexâmico e soro antibotrópico, e o Grupo 5 (G5) com soro antibotrópico e desmopressina. As amostras de sangue foram coletadas antes da administração do veneno, e uma, quatro, oito e 12 horas após os tratamentos para realização de tempo de tromboplastina parcial ativada parcial (TTPa), tempo de protrombina (TP), tempo de trombina (TT) e mensuração de fibrinogênio. Para o ensaio de geração de trombina (TG) foi realizado com um pool de amostras nos tempos finais (8 e 12h). Ao final das 12h, todos os animais foram sacrificados e a necropsia foi realizada. Amostras de tecido muscular, coração, pulmões e rins foram analisadas. Os testes TTPa, TP, TT e fibrinogênio não mostraram diferenças significativas entre os grupos e os tempos. No entanto, o TG indicou que o veneno causa um estado de hipocoagulabilidade, que não foi revertido pelos tratamentos propostos. Na histologia, foram observadas inflamação muscular, hemorragia e necrose, além de hemorragia em outros tecidos, sem diferenças entre os grupos. O envenenamento por B. alternatus causa hipocoagulabilidade detectada mais precocemente pelo teste de geração de trombina. O uso de ácido tranexâmico e desmopressina para estabilização da hemostasia após a inoculação do veneno não mostrou vantagem na restauração da coagulação.

ABSTRACT: In Brazil, snakes from the Bothrops genus are responsible for thousands of accidents, and their venoms are mainly composed of proteolytic enzymes. Although the antibothropic serum produced by the Brazilian Institutes is remarkably efficient, more studies are necessary, especially in veterinary medicine. The venom contain enzymes and non-enzymatic proteins that interfere with hemostasis leading to hemorrhage or even thrombosis. Possible treatment associations with known bothropic antivenom were the reason for the development of the present study. The aim of this study was to evaluate hemostasis alterations caused by Bothrops alternatus venom in rabbits followed by treatments with anti-bothropic serum, tranexamic acid and desmopressin. Twenty New Zealand rabbits were distributed into five groups (n=4) that were experimentally envenomed with 150mcg/kg of B. alternatus venom via intramuscular injection and treated as follow: Group 1 (G1) was the positive control and received venom and PBS/BSA; Group 2 (G2) was treated with tranexamic acid; Group 3 (G3) with desmopressin; Group 4 (G4) with tranexamic acid and anti-bothropic serum; and Group 5 (G5) with anti-bothropic serum and desmopressin. Blood samples were collected before venom administration, and one, four, eight and 12 hours after, for Partial activated partial thromboplastin time, Prothrombin Time, Thrombin Time and fibrinogen evaluation. Thrombin generation (TG) test was carried out with a pool of samples from final times (8 and 12h). At the end of 12h, all animals were euthanized and necropsy was conducted. Samples from muscle tissue, heart, lungs and kidney were analyzed. Classic coagulation tests showed no significant differences amongst groups and times. However, TG indicated that the venom causes a hypocoagulability state, which was not reversed by proposed treatments. Histology showed muscle inflammation, hemorrhage and necrosis, as well as hemorrhage in other tissues with no differences amongst groups. B. alternatus envenomation causes hypocoagulability detected by TG assay, but not through classical coagulation tests. The use of tranexamic acid and desmopressin for hemostasis stabilization after inoculation of the venom did not show advantage in coagulation restoration.

SUMMARY: The Viperidae venoms are composed of a mixture of constituents with enzymatic and non-enzymatic actions, which act on ultrastructural components of cells and tissues. Here, the number of mitochondria, mitochondrial area and the number of mitochondrial cristae from adrenal glands cortex treated with snake venoms were tested after 3, 6 and 24 hours of venom injections. The mitochondria quantitative changes showed a statistically significant decrease, in the number of mitochondria past 3, 6 and 24 h. There was an increase in the mitochondrial area after 6 h, where Crotalus vegrandis venom did not present significant differences with Crotalus pifanorum or Bothrops venezuelensis venoms. After 24 h, there was an escalation of mitochondrial area in all tested venoms. The number of mitochondrial cristae after 3 h did not present important differences with the control treatment. After 6 h, the number of mitochondrial cristae initiated to decrease under the activities of the 3 venoms action, until 24 h of observation. In the qualitative observations it was possible to witness an intense damage of the mitochondria, with loss and swelling of membranes, disappearance of cristae and the appearance of myelin figures, which started at 3 h after the Crotalus and Bothrops venoms injections. These damages probably were due to cytotoxic effects of phospholipases, metalloproteases and/or other proteolytic activities present in Viperidae snake venoms, being more evident in Crotalus venoms. As far as we know, these results define a novel finding that suggest that Viperidae snake venoms are extremely toxic to mammalian mitochondria.

RESUMEN: Los venenos de Viperidae tienen acciones enzimáticas y no enzimáticas, que actúan sobre la estructura celular. Aquí se probaron, a las 3, 6 y 24 horas de la inyección del veneno, el número de mitocondrias, el área mitocondrial y el número de crestas mitocondriales de la corteza de las glándulas adrenales. Los cambios cuantitativos de las mitocondrias mostraron una disminución en el número de mitocondrias a las 3, 6 y 24 h. Hubo un aumento en el área mitocondrial a las 6 h, donde el veneno de la serpiente Crotalus vegrandis no presentó diferencias significativas con los venenos de Crotalus pifanorum o Bothrops venezuelensis. Después de 24 h, hubo un aumento del área mitocondrial en todos los venenos. El número de crestas mitocondriales a las 3 h no presentó alteraciones o diferencias importantes con el tratamiento de control. Después de 6 h, el número de crestas mitocondriales comenzó a disminuir bajo la acción de los 3 venenos, hasta las 24 h de observación. En las observaciones cualitativas se observó un daño intenso de las mitocondrias, con pérdida y edema de las membranas, desaparición de las cristae y aparición de figuras mielínicas, que comenzó a las 3 h después de las inyecciones de veneno de Crotalus y Bothrops. Estos daños se debieron factiblemente a los efectos citotóxicos de componentes proteolíticos de los venenos. Creemos que estos resultados definen un nuevo y original hallazgo, que sugiere que los venenos de serpiente Viperidae son extremadamente tóxicos para las mitocondrias de mamíferos.

Resumen Introducción: Anualmente, en Colombia se informan alrededor de 5000 casos de mordedura de serpiente, que producen un cuadro clínico de envenenamiento, cuya neutralización depende de inmunoglobulinas heterólogas. Comercialmente, en el país se pueden encontrar inmunoglobulinas completas de segunda generación y faboterápicos de tercera generación; sin embargo, muchos médicos tratantes desconocen sus diferencias. Objetivo: Dar a conocer las principales características farmacocinéticas entre las diferentes generaciones de antivenenos, así como la frecuencia de reacciones adversas. Materiales y métodos: Se buscó literatura sobre el tema en diversas bases de datos, utilizando combinaciones de los descriptores y términos MeSH, en inglés y español. Se cotejaron parámetros farmacocinéticos en estudios preclínicos y los efectos adversos en estudios clínicos. Resultados: Según los estudios analizados, se encontró que las principales diferencias farmacocinéticas son consecuencia del tamaño de la fracción de la inmunoglobulina; así, los faboterápicos tienen una mayor distribución a los tejidos y una vida media más corta comparada con las inmunoglobulinas completas. En el ámbito clínico se encontraron estudios que evidenciaron de mayor a menor presentación de reacciones adversas a las inmunoglobulinas completas, seguida de los antivenenos F(ab')2 y Fab, respectivamente. Conclusión: Existen grandes diferencias farmacológicas entre las generaciones de los antivenenos antiofídicos, las cuales se exponen en este artículo como una herramienta práctica para optimizar el adecuado tratamiento en la mordedura de serpiente.

Abstract Introduction: In Colombia, around 5000 cases of snakebites are reported annually, producing a clinical poisoning whose neutralization depends on heterologous immunoglobulins. Commercially, second-generation complete immunoglobulins and third-generation fabotherapies can be found; however, their differences are unknown to many physicians. Objective: To present the main pharmacokinetic characteristics by comparing the different generations of antivenoms, as well as the frequency of side effects. Materials and Methods: A literature search was conducted in databases using a combination of descriptors and Mesh terms, in English and Spanish. Pharmacokinetic parameters were compared in preclinical studies and side effects in clinical studies. Results: From the researchers analyzed, we found that the main pharmacokinetic differences are a consequence of the size of the immunoglobulin fraction, so the fabotherapic have a greater distribution to the tissues and a shorter half-life, compared with the complete immunoglobulins. At a clinical level, studies were found that showed higher to lower presentation of side effects to complete immunoglobulins, followed by antivenoms F(ab´)2 and Fab respectively. Conclusion: There are big pharmacological differences between the generations of antivenoms, which are exposed in this document as a practical tool to optimize the adequate pharmacological treatment in snakebite.

ABSTRACT Bothrops erythromelas are serpents that belong to the Viperidae family, which are the main species responsible for human snakebites in Ceara State, Northeast Brazil. Thrombotic microangiopathy (TMA) is an uncommon group of disorders characterized by microangiopathic hemolytic anemia (MAHA), thrombocytopenia and acute kidney injury (AKI), and occurrence after snakebites have been rarely reported. In this report, we described the case of a 57 year-old-man without comorbidities who was bitten by a Bothrops erythromelas on his right ankle. He presented with pain, edema and local bleeding. Symptomatology and laboratory tests were compatible with the diagnosis of TMA. He received specific antivenom and fluids replacement without any anaphylactic reaction. The conservative treatment was effective and there was no need for red blood cells transfusion or plasmapheresis. The aim of this report was to describe the first case of thrombotic microangiopathy following Bothrops erythromelas envenoming in the Northeast Brazil, providing insights about important mechanistic pathways of Bothrops snakebite-associated TMA and how to change the prognosis of the disease.

Abstract Background: Endogenous phospholipase A2 inhibitors from snake blood (sbPLIs) have been isolated from several species around the world, with the primary function of self-protection against the action of toxic phospholipases A2. In American snakes, sbPLIs were solely described in pit vipers, in which the natural protection role is justified. In this study, we described a sbPLI in Boa constrictor (popularly known as jiboia), a non-venomous snake species from America. Methods: PLA2 inhibitory activity was tested in the blood plasma of B. constrictor using C. d. terrificus venom as the enzyme source. Antibodies developed against CNF, a sbγPLI from Crotalus durissus terrificus, were used to investigate the presence of homologues in the blood plasma of B. constrictor. A CNF-like molecule with a PLA2 inhibitory activity was purified by column chromatography. The encoding gene for the inhibitor was cloned from B. constrictor liver tissue. The DNA fragment was cloned, purified and sequenced. The deduced primary sequence of interest was aligned with known sbγPLIs from the literature. Results: The blood plasma of B. constrictor displayed PLA2 inhibitory activity. A CNF-like molecule (named BcNF) was identified and purified from the blood plasma of B. constrictor. Basic properties such as molecular mass, composing amino acids, and pI were comparable, but BcNF displayed reduced specific activity in PLA2 inhibition. BcNF showed highest identity scores (ISs) with sbγPLIs from pit vipers from Latin America (90-100%), followed by gamma inhibitors from Asian viperid (80-90%). ISs below 70% were obtained for BcNF and non-venomous species from Asia. Conclusion: A functional sbγPLI (BcNF) was described in the blood plasma of B. constrictor. BcNF displayed higher primary identity with sbγPLIs from Viperidae than to sbγPLIs from non-venomous species from Asia. The physiological role played by sbγPLIs in non-venomous snake species remains to be understood. Further investigation is needed.

Resumo: Serpentes compõem um diverso grupo de animais vertebrados terrestres pertencentes à ordem Squamata. Apesar de serem um dos grupos mais diversos do mundo, na Amazônia, as informações acerca da taxonomia e distribuição de serpentes são limitadas quando comparadas com as disponíveis para outros grupos de vertebrados. Além disso, na Amazônia existe um viés de amostragem em áreas geograficamente próximas aos centros urbanos e locais densamente povoados. Isso por sua vez leva a falsas diferenças de distribuição em áreas pouco amostradas. Neste artigo nós apresentamos a composição de assembleias de serpentes em seis áreas na Amazônia brasileira, baseada em amostragens de campo padronizadas e realizadas durante quatro anos. Foram amostradas 70 espécies de oito famílias: Typhlopidae (n=1), Leptotyphlopidae (n=1), Anillidae (n=1), Boidae (n=5), Colubridae (n=15), Dipsadidae (n=35), Elapidae (n=7) e Viperidae (n=5). A maior riqueza foi registrada no Rio Trombetas e a menor no Rio Jatapu. A beta diversidade total foi de 0.40 e a substituição foi a principal força que estruturou as comunidades (72.5%). A Procura Visual Limitada por Tempo foi o método que registrou a maior abundância de serpentes nas áreas amostradas (44.1%) e também a maior riqueza (n=40). Entretanto, algumas espécies foram registradas somente por outros métodos como armadilhas de interceptação e queda. Apesar do grande número de espécies registradas, nenhuma das áreas compreendeu mais de 40% das espécies amostradas em todas as áreas, indicando que as serpentes são pouco detectadas mesmo com grande esforço amostral em diferentes áreas da distribuição das espécies.

Abstract: Snakes are a diverse group of terrestrial vertebrates of the order Squamata. Despite that, in the Amazonian biome, information about distribution and identification of snakes is limited when compared to other groups. Additionally, in Amazonia there is a sampling bias towards areas geographically close to urban centers and more densely populated areas. This in turn leads to false distribution gaps in poorly accessible areas of Amazonia. In this article we report the composition of snake assemblages in six areas of the Brazilian Amazonia, based on field sampling conducted over four years using standardized methods. We sampled 70 species from eight families: Typhlopidae (n=1), Leptotyphlopidae (n=1), Anillidae (n=1), Boidae (n=5), Colubridae (n=15), Dipsadidae (n=35), Elapidae (n=7), and Viperidae (n=5). The largest number of species was recorded in the Trombetas River area and the lowest in the Jatapu River area. The total beta diversity was 0.40 and the snake assemblages were structured mainly by replacement (72.5%). The time-limited search was the method that recorded the greatest number of individuals in the studied areas (44.1%) and also the greatest number of species (n=40). However, some species were recorded only by other methods such as interception by pitfall traps with directional fences. Despite the large number of species sampled in the study, no particular area comprised more than 40% of species registered in all the areas, indicating that snakes are poorly detected even with large sampling effort across multiple areas of a species distribution.

ABSTRACT Envenomation by poisonous snakes is frequent in Paraguay, particularly in the departments bordering with Brazil, and can be severe if the species involved belongs to the families Viperidae or Elapidae. It mostly affects 20-40 year old men involved in agricultural activities. Eastern Paraguay, together with southeast Brazil, has been identified as one of the highest snakebite incidence areas in the Neotropics. This review presents available epidemiological data and revises the physiopathology of the envenomation, particularly in the case of viperid venoms, as well as the current distribution of species in genera Bothrops and Micrurus in Paraguay. It posits the need to prepare a national reference venom based on Paraguay´s biodiversity to pave the way for testing the neutralization capacity of foreign antivenoms or for the preparation of a national snake antivenom.

RESUMEN El accidente ofídico en el Paraguay es un evento frecuente que reviste gravedad si la serpiente asociada pertenece a las familias Viperidae y Elapidae, particularmente en los departamentos fronterizos con el Brasil, en donde afecta principalmente a hombres en actividades agrícolas entre los 20 y 40 años de edad. El oriente del Paraguay, junto con el sudeste del Brasil, ha sido identificado como una de las áreas de mayor incidencia de ofidismo en todo el Neotrópico. Se presenta una revisión de la problemática desde el punto de vista epidemiológico y fisiopatológico, conjuntamente con la distribución de las especies de potencial importancia médica de los géneros Bothrops y Micrurus. Se plantea la necesidad de elaborar un veneno de referencia nacional que represente las especies asociadas a los envenenamientos severos y que permita la evaluación de la capacidad neutralizante de antídotos foráneos, así como la eventual preparación de un antiveneno nacional.