Variaciones de caracteres morfológicos dentro de la especie Bothrops alternatus / Morphological characters variations within the Bothrops alternatus species

Resumen El género Bothrops (yarará) es responsable de más del 95% de los accidentes por ofidios venenosos en Argentina. La mayoría de éstos son notificados en provincias del Nordeste y Noroeste. Bothrops alternatus, es la especie más frecuentementehallada, siendo el vipérido de gran talla más meridional del mundo y una de las especies de mayor importancia sanitaria en Argentina, pudiendo hallarse en relación a núcleos urbanos. Presentan en el dorso figuras arriñonadas características, que remedan atubos de teléfono o porotos unidos, completos o incompletos, hasta la forma fusionada. Presenta foseta loreal, órgano termore-ceptor ubicado entre el ojo y la fosa nasal. Su dentición es solenoglifa, dientes inoculadores huecos, con conducto cerrado, fijosa un hueso maxilar móvil. Si bien se describen variaciones entre animales, se considera una especie monotípica. Su identificaciónes importante dada la abundancia de especímenes y de hallazgos en regiones periurbanas.

Abstract The Bothrops genus is responsible for more than 95% of ophidian accidents in Argentina, most of these are reported in the Northeast and Northwest provinces. Bothrops alternatus, is the most frequent species of the genus Bothrops (yarará), themost southern large-scale viperid in the world and one of the most important species in Argentina, being able to be found in rela-tion to urban nucleus. Their characteristic features are kidney-like figures in the skin, that mimic phone tubes or beans, completeor incomplete, until the merged form. It presents a loreal pit, thermoreceptor organ located between the eye and the nostril. Itsdentition is solenoglyphous, hollow inoculating teeth, with closed duct, fixed to a mobile maxillary bone. Although variationsbetween animals are described, it is considered a monotypic species. The identification of this snake is important due their abun-dance in around urban regions and its frequency of finding.

De novo venom gland transcriptomics of Calliophis bivirgata flaviceps: uncovering the complexity of toxins from the Malayan blue coral snake

The Malayan blue coral snake, Calliophis bivirgata flaviceps, is a medically important venomous snake in Southeast Asia. However, the complexity and diversity of its venom genes remain little explored. Methods: To address this, we applied high-throughput next-generation sequencing to profile the venom gland cDNA libraries of C. bivirgata flaviceps. The transcriptome was de novo assembled, followed by gene annotation, multiple sequence alignment and analyses of the transcripts. Results: A total of 74 non-redundant toxin-encoding genes from 16 protein families were identified, with 31 full-length toxin transcripts. Three-finger toxins (3FTx), primarily delta-neurotoxins and cardiotoxin-like/cytotoxin-like proteins, were the most diverse and abundantly expressed. The major 3FTx (Cb_FTX01 and Cb_FTX02) are highly similar to calliotoxin, a delta-neurotoxin previously reported in the venom of C. bivirgata. This study also revealed a conserved tyrosine residue at position 4 of the cardiotoxin-like/cytotoxin-like protein genes in the species. These variants, proposed as Y-type CTX-like proteins, are similar to the H-type CTX from cobras. The substitution is conservative though, preserving a less toxic form of elapid CTX-like protein, as indicated by the lack of venom cytotoxicity in previous laboratory and clinical findings. The ecological role of these toxins, however, remains unclear. The study also uncovered unique transcripts that belong to phospholipase A2 of Groups IA and IB, and snake venom metalloproteinases of PIII subclass, which show sequence variations from those of Asiatic elapids. Conclusion: The venom gland transcriptome of C. bivirgata flaviceps from Malaysia was de novo assembled and annotated. The diversity and expression profile of toxin genes provide insights into the biological and medical importance of the species.(AU)

Exploring the five-paced viper (Deinagkistrodon acutus) venom proteome by integrating a combinatorial peptide ligand library approach with shotgun LC-MS/MS

Snake venoms are complex mixtures of toxic proteins or peptides encoded by various gene families that function synergistically to incapacitate prey. In the present study, in order to unravel the proteomic repertoire of Deinagkistrodon acutus venom, some trace abundance components were analyzed. Methods Shotgun proteomic approach combined with shotgun nano-LC-ESI-MS/MS were employed to characterize the medically important D. acutus venom, after collected samples were enriched with the combinatorial peptide ligand library (CPLL). Results This avenue helped us find some trace components, undetected before, in D. acutus venom. The results indicated that D. acutus venom comprised 84 distinct proteins from 10 toxin families and 12 other proteins. These results are more than twice the number of venom components obtained from previous studies, which were only 29 distinct proteins obtained through RP-HPLC for the venom of the same species. The present results indicated that in D. acutus venom, the most abundant components (66.9%) included metalloproteinases, serine proteinases, and C-type lectin proteins; the medium abundant components (13%) comprised phospholipases A2 (PLA2) and 5'-nucleotidases and nucleases; whereas least abundant components (6%) were aminopeptidases, L-amino acid oxidases (LAAO), neurotoxins and disintegrins; and the trace components. The last were undetected before the use of conventional shotgun proteomics combined with shotgun nano-LC-ESI-MS/MS, such as cysteine-rich secretory proteins Da-CRPa, phospholipases B-like 1, phospholipases B (PLB), nerve growth factors (NGF), glutaminyl-peptide cyclortransferases (QC), and vascular non-inflammatory molecules 2 (VNN2). Conclusion These findings demonstrated that the CPLL enrichment method worked well in finding the trace toxin proteins in D. acutus venom, in contrast with the previous venomic characterization of D. acutus by conventional LC-MS/MS. In conclusion, this approach combined with the CPLL enrichment was effective for allowing us to explore the hidden D. acutus venomic profile and extended the list of potential venom toxins.(AU)

Hemorragia cerebral fatal después de una mordedura de serpiente Bothrops asper en la región del Catatumbo, Colombia / Fatal brain hemorrhage after Bothrops asper bite in the Catatumbo region of Colombia

Resumen: Las mordeduras de serpientes son un problema de salud pública en regiones tropicales y subtropicales del mundo. Ocurren, especialmente, en trabajadores rurales, y son una importante fuente de discapacidad y mortalidad. Se presenta el caso de un hombre de 59 años, agricultor de la región del Catatumbo (Colombia), quien sufrió la mordedura de una serpiente Bothrops asper, la cual le produjo una hemorragia cerebral fatal. Se llama la atención sobre el grave trastorno hemorrágico en contraste con los leves cambios en el sitio de la mordedura, así como sobre la necesidad del tratamiento temprano de la intoxicación con el suero antiofídico, incluso, en ausencia de manifestaciones cutáneas significativas.

Abstract: Snake bites are a public health problem in tropical and subtropical regions of the world. They occur especially in rural workers and are an important source of disability and mortality. We present the case of a 59-year-old farmer from the Catatumbo region of Colombia who was bitten by a B. asper snake and suffered a fatal brain hemorrhage after the event. We draw attention to the severe bleeding disorder in contrast with the slight changes at the site of the bite, as well as on the importance of the early treatment of poisoning with antivenom even in the absence of significant skin manifestations.

Qualitative and quantitative ultrastructural analysis of the mitochondria from adrenal gland cortex under the action of viperidae family snake venoms / Análisis ultrastructural cualitativo y cuantitativo de la mitocondria de la glándula adrenal bajo la acción de los venenos de serpientes de la familia viperidae

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.

Protein structure of the venom in nine species of snake: from bio-compounds to possible healing agents

Due to its various structures in bio-compounds, snake venom is the indisputable result of evolutionary stages of molecules with an increasingly complex structure, high specificity, and of great importance for medicine because of their potential. The present study proposed an underpinning examination of venom composition from nine species of venomous snakes using a useful and replicable methodology. The objective was the extension of the evaluation of protein fractions in the field up to 230 kDa to permit possible identification of some fractions that are insufficiently studied. The gel capillary electrophoresis method on the chip was performed using an Agilent 2100 bioassay with the 80 and 230-LabChip Protein kits. Interpretation of electrophoresis was performed using the Protein 2100 expert (Agilent) test software as follows: a) Protein 80 (peak size scale): 1.60, 3.5, 6.50, 15.00, 28.00, 46.00, 63.00, 95.00 kDa; b) Protein 230 (peak size scale): 4.50, 7.00, 15.00, 28.00, 46.00, 63.00, 95.00, 150.00, 240.00 kDa. The screening revealed the presence of compounds with a molecular weight greater than 80 kDa, in the case of Vipera aspis and Vipera xantina palestinae. For V. aspis, a 125 kDa molecular weight pro-coagulant protein was identified, known as being involved in the reduction of plasma clotting time without any direct activity in the fibrinogen coagulation process. The samples examined on the Protein 230-LabChip electrophoresis chip can be considered as a novelty with possible uses in medicine, requiring further approaches by advanced proteomics techniques to confirm the intimate structural features and biological properties of snake venoms.

Cytotoxic and anticancer properties of the Malaysian mangrove pit viper (Trimeresurus purpureomaculatus) venom and its disintegrin (purpureomaculin)

The Asiatic pit vipers from the Trimeresurus complex are medically important venomous snakes. These pit vipers are often associated with snakebite that leads to fatal coagulopathy and tissue necrosis. The cytotoxic venoms of Trimeresurus spp.; however, hold great potential for the development of peptide-based anticancer drugs. Methods: This study investigated the cytotoxic effect of the venom from Trimeresurus purpureomaculatus, the mangrove pit viper (also known as shore pit viper) which is native in Malaysia, across a panel of human cancer cell lines from breast, lung, colon and prostate as well as the corresponding normal cell lines of each tissue. Results: The venom exhibited dose-dependent cytotoxic activities on all cell lines tested, with median inhibition concentrations (IC50) ranging from 0.42 to 6.98 µg/mL. The venom has a high selectivity index (SI = 14.54) on breast cancer cell line (MCF7), indicating that it is significantly more cytotoxic toward the cancer than to normal cell lines. Furthermore, the venom was fractionated using C18 reversed-phase high-performance liquid chromatography and the anticancer effect of each protein fraction was examined. Fraction 1 that contains a hydrophilic low molecular weight (approximately 7.5 kDa) protein was found to be the most cytotoxic and selective toward the breast cancer cell line (MCF7). The protein was identified using liquid chromatography-tandem mass spectrometry as a venom disintegrin, termed purpureomaculin in this study. Conclusion: Taken together, the findings revealed the potent and selective cytotoxicity of a disintegrin protein isolated from the Malaysian T. purpureomaculatus venom and suggested its anticancer potential in drug discovery.(AU)

Acute kidney failure following severe viper envenomation: clinical, biological and ultrasonographic aspects

Acute kidney injury (AKI) is a frequent complication of snakebite envenomation, which is still little known in sub-Saharan Africa. This study aims to describe the clinical, biological and ultrasonographic aspects of AKI following severe snakebite envenomation managed in the intensive care unit. Method: A prospective observational survey was performed in Benin over a period of 18 months. All patients suffering severe snakebite envenomation (SBE) were included. The diagnosis of AKI was made using the KDIGO criteria. Kidney ultrasound exam was performed in all patients to assess internal bleeding and morphological and structural abnormalities of the kidneys. Results: Fifty-one cases of severe SBE were included. All patients presented inflammatory syndrome and showed abnormal WBCT whereas bleeding was found in 46 of them (90%). The median time to hospital presentation was three days. The majority of patients were male (M/F sex ratio = 1.55) and the median age was 26. Sixteen patients (31%) showed AKI according to the KDIGO criteria. Severe AKI (KDIGO stage 2 and 3) was observed in three patients, including one stage 2 and two stage 3. Kidney ultrasound revealed three cases of kidney capsular hematoma (6%), two cases of kidney hypertrophy (3%), three cases of kidney injury (4%), two stage 1 KDIGO and one stage 2 KDIGO. Only one patient benefited from hemodialysis. All patients showing AKI recovered without sequels. The median duration of hospital stays was four days. Seven patients died (14%) including four among the 16 AKI patients. Antivenom has been administered to 41 patients (80%). The comparison between patients without and with AKI did not show any significant difference except gender (p = 10-2). Conclusion: AKI is a common complication of severe snakebite envenomation. Resulting from inflammatory and hemorrhagic disorders, AKI may prove to be a short-term life-threatening factor.(AU)

Delayed double reading of whole blood clotting test (WBCT) results at 20 and 30 minutes enhances diagnosis and treatment of viper evenomation

The whole blood clotting test (WBCT) is a simple test of coagulation that is often used in the assessment, diagnosis, and therapeutic monitoring of snakebite patients in sub-Saharan Africa. WBCT requires only a clean glass tube and several milliliters of venous blood and is ideal for use in poorly equipped health centers throughout the rural areas where 95% of snakebites occur. However, questions surrounding the accuracy and reliability of the test remain unanswered due to variations in testing conditions and a lack of comparative research with which to validate them. This is the first study to evaluate WBCT results at both 20-min (WBCT20) and 30-min (WBCT30) reading times in the same group of snakebite patients. Methods In order to define the best reading time, the authors compared the results of serial WBCT evaluation at both 20 and 30 min after collection in 23 patients treated for snake envenomation in Bembèrèkè, northern Benin. Results WBCT results were identical at both reading times in patients without coagulopathy or when coagulation was restored permanently following a single dose of antivenom. Out of 17 patients with coagulopathy, 14 showed discrepancies between WBCT20 and WBCT30 results in at least one pair of serial evaluations. These could be completely contradictory results (e.g. normal clot at WBCT20 and no clot at WBCT30) or a marked difference in the quality of the clot (e.g. no clotting activity at WBCT20 and an unstable partial clot at WBCT30). WBCT discrepancies were encountered most frequently in three situations: initial normalization of hemostasis following antivenom therapy, detection of a secondary resumption of coagulopathy, or final restoration of hemostasis after a secondary resumption had occurred. Conclusions This study suggests that the WBCT is robust and that a sequential reading should improve the diagnosis and monitoring of venom-induced coagulopathies. It also indicates the possibility of discrepancies in the sensitivity of WBCT20 and WBCT30 for detecting the resolution or reoccurrence of coagulopathy and identifies how these findings, if confirmed, may be used to increase the efficacy and efficiency of antivenom treatment in the field.(AU)

Estudio descriptivo del accidente ofídico, Casanare-Colombia, 2012-2014 / ADescriptive Study of Ophidian Accidents, Casanare-Colombia, from 2012 to 2014 / Estudo descritivo do acidente ofídico, Casanare-Colômbia, 2012-2014

Introducción: Entre las lesiones de causa externa, el accidente ofídico es de notificación obligatoria en Colombia. En el departamento de Casanare, la susceptibilidad de sufrir una mordedura de serpiente aumenta dadas sus características geográficas, climáticas, socioculturales y demográficas que favorecen el incremento de morbilidad y mortalidad. Objetivo: Describir la ocurrencia del evento en Casanare entre 2012-2014, con el propósito de fortalecer las acciones de promoción y prevención. Metodología: Estudio descriptivo transversal a partir de registros de la notificación del evento al Sistema de Vigilancia en Salud Pública durante el período a estudio; la información se almacenó en el programa Excel de Microsoft Office®, y se realizó un análisis descriptivo de las variables tiempo, lugar y persona en el programa estadístico Epi-Info 7.1.5®. Resultados: Se registraron 485 casos: en 2012 (175 casos; 36.1%), 2013 (168 casos; 34.6%), 2014 (142 casos; 29.3%); de los cuales 315 fueron en hombres (64.9%), 417 casos del área rural (85.9%), con una edad promedio de 32.4 ± 19.9. En relación a la pertenencia étnica se presentaron 49 casos (10.1%), de los cuales el 83.7% fue en indígenas (41/49). Las actividades más frecuentes al momento de la agresión fueron caminatas por senderos abiertos o labores de agricultura 280 casos (57.7%); realizar trabajos agropecuarios, forestales o pesqueros 124 casos (25.6%). La localización anatómica de la mordedura en orden de frecuencia fue: Miembros inferiores 351 casos (72.4%) y superiores 113 casos (23.3%). Según la atención inicial: Inmovilización de miembro 71 casos (14.7%); sometidos a prácticas no médicas 181 casos (37.3%), y el 54.7% (99/181) se había realizado rezos. La Tasa de incidencia fue de 47.1/100,000 habitantes y de letalidad 0.2% (1/485). Conclusiones: La tasa de incidencia evidenciada superó la del país de 9.2/100,000 habitantes. Afectó a hombres en edad productiva, dependientes del trabajo agrícola; y la atención inicial fue inadecuada en la mayoría de casos, persistiendo el uso de prácticas no médicas. Todas las lesiones son prevenibles, por tanto, las medidas preventivas deben constituirse en la principal herramienta para reducir la incidencia del evento. [Manosalva-Sánchez C, Zuleta-Dueñas LP, Castañeda-Porras O. Estudio descriptivo del accidente ofídico, Casanare-Colombia, 2012-2014. MedUNAB 2017-2018; 20(3): 338-348].

Introduction: Among the injuries of external cause, the ophidian accident is notifiable in Colombia. In the department of Casanare, the susceptibility to suffer a snake bite increases given its geographical, climatic, sociocultural and demographic characteristics that favor the growth of morbidity and mortality. Objective: To describe the occurrence of the event in Casanare between 2012 and 2014, with the purpose of strengthening the actions of promotion and prevention. Methodology:Atransversal descriptive study from records of the notification of the event to the Public Health Surveillance System during the study period. The information was stored in the Microsoft Office® Excel program, and a descriptive analysis of the time, place and person variables was performed in the Epi-Info 7.1.5® statistical program. Results: 485 cases were registered; in 2012 (175 cases; 36.1%), 2013 (168 cases; 34.6%), 2014 (142 cases; 29.3%); cases of which 315 were caused in men (64.9%), 417 cases in the rural area (85.9%), with an average age of 32.4 ± 19.9. Regarding ethnicity, 49 cases were presented (10.1%), of which 83.7% were indigenous (41/49). The most frequent activities at the time of the attack were hiking on open trails or agricultural work with 280 cases (57.7%); performing agricultural, forestry or fishing jobs with 124 cases (25.6%). The anatomical location of the bite in order of frequency was: lower limbs 351 cases (72.4%) and upper limbs 113 cases (23.3%). According to the initial care: immobilization of limbs 71 cases (14.7%); undergoing non-medical practices 181 cases (37.3%), and 54.7% (99/181) preferred to undergo to prays. The incidence rate was 47.1 / 100,000 inhabitants and lethality 0.2% (1/485). Conclusions: The observed incidence rate exceeded the one of the country of 9.2 / 100,000 inhabitants. It affected men of productive age, who were dependent on agricultural work; and their initial care was inadequate in most cases, and the use of non-medical practices was persistent. All injuries are preventable; therefore, preventive measures should be the main tool to reduce the incidence of this accident. [Manosalva-Sánchez C, Zuleta-Dueñas LP, Castañeda-Porras O. A Descriptive Study of Ophidian Accidents, Casanare-Colombia, from 2012 to 2014. MedUNAB 2017-2018; 20(3): 338-348].

Introdução: Entre os feridos de causas externas, o acidente ofídico é uma notificação obrigatória na Colômbia. No estado do Casanare, a suscetibilidade a uma mordida de cobra aumenta devido às características geográficas, climáticas, socioculturais e demográficas que favorecem o aumento da morbidade e mortalidade. Objetivo: Descreva a ocorrência do evento em Casanare entre 2012-2014, com o objetivo de fortalecer as ações de promoção e prevenção. Metodologia: Estudo descritivo transversal de registos da notificação do evento ao Sistema de Vigilância de Saúde Pública durante o período de estudo; a informação foi armazenada no programa Microsoft Office® Excel e uma análise descritiva das variáveis tempo, lugar e pessoa foi realizada no programa estatístico Epi-Info 7.1.5®. Resultados: 485 casos foram registrados: em 2012 (175 casos, 36.1%), 2013 (168 casos, 34.6%), 2014 (142 casos, 29.3%); dos quais 315 eram homens (64.9%), 417 casos na área rural (85.9%), com idade média de 32.4 ± 19.9. Em relação à etnia, houve 49 casos (10.1%), dos quais 83.7% eram indígenas (41/49). As atividades mais freqüentes no momento da agressão foram caminhadas em trilhas abertas ou trabalho agrícola 280 casos (57.7%); realizar trabalhos agrícolas, florestais ou de pesca 124 casos (25.6%). A localização anatômica da mordida em ordem de freqüência foi: membros mais baixos 351 casos (72.4%) e maiores 113 casos (23.3%). De acordo com os cuidados iniciais: Imobilização de 71 casos (14.7%); passando por práticas não médicas 181 casos (37.3%) e 54.7% (99/181) rezaram. A taxa de incidência foi de 47.1/100,000 habitantes e letalidade 0.2% (1/485). Conclusões: A taxa de incidência evidenciada excedeu a do país em 9.2/100,000 habitantes. Isso afetou homens em idade produtiva, dependentes do trabalho agrícola; e o cuidado inicial foi inadequado na maioria dos casos, persistindo o uso de práticas não médicas. Todas as lesões são evitáveis, portanto, as medidas preventivas devem ser a principal ferramenta para reduzir a incidência do evento. [Manosalva-Sánchez C, Zuleta-Dueñas LP, Castañeda-Porras O. Estudo descritivo do acidente ofídico, Casanare-Colômbia, 2012-2014. MedUNAB 2017-2018; 20(3): 338-348].

Aislamiento y caracterización de la miotoxina I del complejo Bothrops neuwiedi (yarará chica) / Isolation and characterization of myotoxin I from Bothrops neuwiedi complex (small yarará)

En Argentina, más del 97% de los accidentes ponzoñosos son producidos por serpientes del género Bothrops, siendo aquellas pertenecientes al complejo Bothrops neuwiedi unas de las de mayor incidencia. El envenenamiento por esta especie es similar al descripto para otras especies Bothrops de América, presentando en el individuo accidentado daño tisular considerable: dolor, inflamación, edema, exudación, mionecrosis, problemas en la coagulación y hemorragias importantes. Del veneno entero del complejo Bothrops neuwiedi se aisló una proteína básica por cromatografía de intercambio iónico y RP-HPLC, la que se denominó Miotoxina I. Esta proteína provocó edema, miotoxicidad local cuando se la ensayó en ratones, citotoxicidad en cultivos celulares y alteración a nivel de la coagulación sanguínea, con potencia comparable al de otros venenos del género Bothrops. Con el objeto de determinar en qué medida esta toxina era importante en el daño que provoca el veneno entero de serpientes del complejo Bothrops neuwiedi cuando se produce un accidente ofídico, se caracterizó la misma a nivel bioquímico determinando las siguientes actividades: letal, necrótica, hemorrágica, miotóxica, edematizante, desfibrinogenante, citotóxica y enzimática (fosfolipasa A2). Al inyectar dosis de hasta 4,4 mg/kg de peso de ratón por vía endovenosa, se observó que la toxina no era letal, a su vez no produjo necrosis ni hemorragia, como se observa cuando se inyecta el veneno crudo, tampoco se detectó actividad fosfolipasa A2 cuando se la ensayó sobre fosfolípidos de yema de huevo. Sin embargo, sí se observó un aumento de la enzima cretinina kinasa (CK) debido al daño producido en tejido muscular, y de la enzima lactato deshidrogenasa (LDH) cuando se la inoculó a líneas celulares endoteliales (t-END) y mioblastos (C2C12) de ratón, observándose un daño en la monocapa celular a partir de las 3H de inoculada la toxina. A nivel sanguíneo se pudo determinar que esta nueva toxina posee actividad anticoagulante en un porcentaje menor al que provoca el veneno entero cuando es inoculado. Con el fin de determinar su peso molecular se realizó una electroforesis en gel de poliacrilamida con dodecyl sulfato de sodio, donde se observó que la Miotoxina I de BnC aparecía, al colorear el gel, como un homodímero de 15 kD. Al realizar una inmunodifusión en gel de agarosa, se observó que existe un patrón de identidad antigénica parcial entre esta nueva miotoxina aislada y la miotoxina II del veneno de la especie Bothrops asper de Costa Rica. A su vez, se secuenciaron los primeros 40 residuos aminoacídicos de esta miotoxina, lo que demostró una alta homología con varias miotoxinas fosfolipasas A2 clase II, de la familia de las Lys-49, de crotálidos. Estos resultados en conjunto sugieren que esta toxina es un nuevo miembro de las fosfolipasas A2 Lys-49, con actividades: miotóxica, citolítica e inflamatoria por inducción de edema y con actividad anticoagulante probablemente por el consumo de fibrinógeno en el torrente sanguíneo.

In vitro antischistosomal activity of venom from the Egyptian snake Cerastes cerastes

Abstract INTRODUCTION: We studied the potential in vitro antischistosomal activity of Cerastes cerastes venom on adult Schistosoma mansoni worms. METHODS: Live specimens of the horned viper snake, C. cerastes were collected from the Aswan Governorate (Egypt). Venom was collected from snakes by manual milking. Worms of S. mansoni were obtained from infected hamsters by perfusion and isolated from blood using phosphate buffer. Mortality rates of worms were monitored after 3 days of exposure to snake venom at LC50 and various sublethal concentrations (10, 5, 2.5µg/ml). Scanning electron microscopy was used to investigate tegumental changes in treated worms after exposure to LC50 doses of venom. RESULTS: The LC50 of C. cerastes venom was 21.5µg/ml. The effect of C. cerastes venom on Schistosoma worms varied according to their sex. The mortality rate of male and female worms after 48-h exposure was 83.3% and 50%, respectively. LC50 of C. cerastes venom induced mild to severe tegumental damage in Schistosoma worms in the form of destruction of the oral sucker, shrinkage and erosion of the tegument, and loss of some tubercle spines. CONCLUSIONS: The present study demonstrated that C. cerastes venom exerts potential in vitro antischistosomal activity in a time and dose-dependent manner. These results may warrant further investigations to develop novel schistosomicidal agents from C. cerastes snake venom.

Caracterización de pacientes que sufrieron mordedura de serpiente, atendidos en Hospital Público de Juticalpa, Olancho / Characterization of snakebite patients treated at the public hospital of Juticalpa, Olancho

La mordedura de serpiente es un problema mundial con incidencia de 2.5 millones de casos anuales, en Honduras se registran 700 casos al año; en el departamento de Olancho el accidente ofídico se relaciona con la actividad agrícola, siendo causa de morbimortalidad. Objetivo: Describir las características epidemiológicas y demográficas de pacientes que sufrieron mordedura de serpiente atendidos en el Hospital San Francisco de Asís, Juticalpa, Olancho. Material y Métodos: Se realizó un estudio descriptivo, retrospectivo y transversal. El universo fue de 76 casos por mordedura de serpiente en el periodo enero 2014-diciembre 2015; la muestra fue 59 expedientes clínicos. La recolección de datos se obtuvo mediante aplicación de instrumentos obteniéndose la información de los expedientes clínicos. Resultados: la distribución de los 59 casos reportó 36(61%) y 23(39%) casos, para los años 2014 y 2015 respectivamente; la media de edad fue 24 años, los pacientes menores de 18 años fueron 27(45.8%) y 32(54.2%) mayores. El promedio de hospitalización de 2.6 días. Los sitios anatómicos más afectados fueron: píe izquierdo 14(23.7%) y píe derecho 13(22%); la medición del sitio anatómico afectado se realizó en 43(72.8%) de los casos. El tiempo transcurrido desde el momento de la mordedura hasta la aplicación del suero antiofídico fue menor de 2 horas en 9(15%) casos; entre 3-8 horas en 23(39%) y mayor de 8 horas en 27(46%). Conclusión: La frecuencia de mordeduras de serpiente fue de 36 casos en el 2014 y 23 en 2015. Las zonas de mayor procedencia de personas afectadas fueron Catacamas y Dulce Nombre de Culmí. La actividad de mayor riesgo para sufrir accidente ofídico en el hombre es la agricultura y en las mujeres las actividades peridomiciliares. La mayor frecuencia de casos se presentó en los meses de agosto, septiembre y octubre en ambos años...(AU).

Anticancer properties of phospholipase A2 fromDaboia siamensis venom on human skin melanoma cells

Background Phospholipase A2 (PLA2) is a major component of theDaboia siamensis venom, which is able to hydrolyse the membrane of various cells. For this reason, the activity of PLA2was investigated regarding its pharmaceutical properties. This study was conducted to explore the pharmacological properties of a PLA2from Daboia siamensis (dssPLA2) venom on human skin melanoma cell line (SK-MEL-28). Methods dssPLA2 was isolated by ion exchange and gel filtration columns. Various concentrations of dssPLA2were investigated for cytotoxic activity and inhibition of migration on SK-MEL-28 cells. Cell death analysis, mRNA expression levels of Notch I-III and BRAF V600E genes were also determined. Results dssPLA2 exhibited cytotoxicity on SK-MEL-28 for 24 and 72 h as compared with untreated cells. However, it had no toxic effects on CCD-1064sk cells under the same conditions. dssPLA2 (0.25 and 0.5 μg/mL) induced 17.16 and 30.60 % of apoptosis, while activated 6.53 and 7.05 % of necrotic cells. dssPLA2 at 0.25, 0.5, 1 and 2 μg/mL could inhibit migration on SK-MEL-28 cells for 24 h by 31.06, 41.66, 50 and 68.75 %, respectively. The action of dssPLA2 significantly reduced the levels of Notch I and BRAF V600E genes expression on SK-MEL-28 cells compared with untreated cells at 72 h. Conclusions This study indicates that dssPLA2 had potential effects of apoptosis, necrosis, cytotoxicity and inhibition of migration on SK-MEL-28 cells. dssPLA2 could possibly be a selective agent that targets cancer cells without affecting normal cells.(AU)

Anticoagulante lúpico-DRVVT: ensayodel veneno de la víbora de Russell diluido / Lupus anticoagulant-DRVVT: dilute Russell’s viper venom test

Anticoagulante lúpico-DRVVT: ensayodel veneno de la víbora de Russell diluidoLupus anticoagulant-DRVVT: dilute Russell’s viper venom testCódigo SCPC (Sociedad Colombiana de Patología Clínica): 10300. Código CUPS (CodificaciónÚnica de Procedimientos en salud): 902004, 902005. Sección: Hematología. Nivel de complejidad: alto. Metodología: veneno de víbora de Russell, mecánico. Sinónimos: anticoagulantelúpico, screening y confirmatorio; anticoagulante lúpico, ratio.DefiniciónEl anticoagulante lúpico con veneno de víbora de Russell es una prueba que se realiza en pacientes con prolongación del tiempo de tromboplastina parcial activado para definir la presenciade anticoagulante lúpico y el posible diagnóstico de síndrome antifosfolípido.Espectro clínico de aplicaciónEl término de anticoagulante lúpico hace referencia a un grupo heterogéneo de autoanticuerpos que interfieren con las pruebas de coagulación basadas en fosfolípidos, por lo que, característicamente, hay una prolongación del tiempo de tromboplastina parcial activado (APTT). Si bien, el fenómeno observado in vitro sugiere que los anticuerpos reconocen fosfolípidos, estos anticuerpos lo que realmente reconocen en el organismo son ciertas proteínas plasmáticas unidoras de fosfolípidos, tales como la β2 glicoproteína I y la protrombina. Clínicamente, su presencia se asocia con riesgo de trombosis y con pérdidas fetales recurrentes, que en caso de que se presenten se relacionan con el síndrome antifosfolípido.

Antibacterial potential of a basic phospholipase A (VRV-PL-VIIIa) from Daboia russelii pulchella (Russell's viper) venom

Background: Microbial/bacterial resistance against antibiotics poses a serious threat to public health. Furthermore, the side effects of these antibiotics have stimulated tremendous interest in developing new molecules from diverse organisms as therapeutic agents. This study evaluates the antibacterial potential of a basic protein, Vipera russellii venom phospholipase A2 fraction VIIIa (VRV-PL-VIIIa), from Daboia russelii pulchella venom against gram-positive and gram-negative bacteria. Methods: The antibacterial potential of VRV-PL-VIIIa in the presence and absence of an inhibitor (p-bromophenacyl bromide) was tested against gram-positive and gram-negative bacteria and the minimum inhibitory concentration was determined by microdilution tests. Results: VRV-PL-VIIIa demonstrated potent antibacterial activities against all the human pathogenic strains tested. It more effectively inhibited such gram-positive bacteria as Staphylococcus aureus and Bacillus subtilis, when compared to the gram-negative bacteria Escherichia coli, Vibrio cholerae, Klebsiella pneumoniae and Salmonella paratyphi. It inhibited bacterial growth at minimum inhibitory concentration values ranging from 11.1 to 19.2 μg/mL. The anti-bacterial potential of VRV-PL-VIIIa was comparable to the standards gentamycin, chlorophenicol and streptomycin. The PLA2's hemolytic and antibacterial activities were strongly correlated. Furthermore, even in the presence of p-bromophenacyl bromide, intense antibacterial activity was observed, suggesting a dissociation or partial overlapping of the bactericidal/antimicrobial domains. Conclusion: VRV-PL-VIIIa demonstrated potent antibacterial activities against all the human pathogenic strains tested. The study shows that despite a strong correlation between enzymatic and antimicrobial activities of VRV-PL-VIIIa, it may possess additional properties that mimic the bactericidal/membrane permeability-increasing protein. This study encourages further in-depth studies on the molecular mechanisms of antibacterial properties of VRV-PL-VIIIa, which would thereby facilitate development of this protein into a possible therapeutic lead molecule for treating bacterial infections.

Snakes and snakebite envenoming in Northern Tanzania: a neglected tropical health problem

Background Snakebites cause considerable human and livestock injuries as well as deaths worldwide, and particularly have a high impact in sub-Saharan Africa. Generating a basic platform of information on the characteristics of snakes and snakebites in various countries is relevant for designing and implementing public health interventions.Methods This study was performed to identify types of snakes and some of the characteristics of snakebite cases in two communities, an agricultural and a pastoralist, in Arusha region, northern Tanzania. A total of 30 field visits were carried out in areas considered by local inhabitants to be potential microhabitats for snakes. Direct observation of snake types based on morphological features and a structured questionnaire were employed for data collection.Results A total of 25 live and 14 dead snakes were encountered. Among the dead ones, the following species were identified: two black-necked spitting cobras (Naja nigricollis); five puff adders (Bitis arietans), one common egg-eater (Dasypeltis scabra); two rufous-beaked snakes (Ramphiophis rostratus); two brown house snakes (Lamprophis fuliginosus); one Kenyan sand boa (Eryx colubrinus), and one black mamba (Dendroaspis polylepis). The frequency of snake encounters was significantly higher (2 = 4.6; p= 0.03) in the pastoral than in the agricultural area; there were more snakebite cases in the former, but the differences were not statistically significant (p= 0.7). A total of 242 snakebite victims attended at the Meserani Clinic, located in the study area, between the years 2007 to 2012. Of all cases, 146 (61.6 %) and 96 (38.4 %) were male and female patients, respectively. As for age distribution, 59.1 % of snakebite victims were from the economically active age groups between 15 and 55 years.Conclusion Snakebites are a threat to rural communities and public health in general. The burden of snakebites in Tanzania presents an epidemiologically similar picture to other tropical countries. Livestock keeping and agriculture are the major economic activities associated with snakebites. Community-based public education is required to create awareness on venomous snakes and predisposing factors to snakebites. These tasks demand integration of diverse stakeholders to achieve a common goal of reducing the impact of human suffering from these envenomings in Tanzania.

Molecular cloning of a hyaluronidase from Bothrops pauloensis venom gland

Hyaluronate is one of the major components of extracellular matrix from vertebrates whose breakdown is catalyzed by the enzyme hyaluronidase. These enzymes are widely described in snake venoms, in which they facilitate the spreading of the main toxins in the victim’s body during the envenoming. Snake venoms also present some variants (hyaluronidases-like substances) that are probably originated by alternative splicing, even though their relevance in envenomation is still under investigation. Hyaluronidases-like proteins have not yet been purified from any snake venom, but the cDNA that encodes these toxins was already identified in snake venom glands by transcriptomic analysis. Herein, we report the cloning and in silico analysis of the first hyaluronidase-like proteins from a Brazilian snake venom.

Presumptive thrombotic thrombocytopenic purpura following a hump-nosed viper (Hypnale hypnale) bite: a case report

Hump-nosed viper bites are frequent in southern India and Sri Lanka. However, the published literature on this snakebite is limited and its venom composition is not well characterized. In this case, we report a patient with thrombotic thrombocytopenic purpura-like syndrome following envenoming which, to the best of our knowledge, has not been reported in the literature before. A 55-year-old woman from southern Sri Lanka presented to the local hospital 12 hours after a hump-nosed viper (Hypnale hypnale) bite. Five days later, she developed a syndrome that was characteristic of thrombotic thrombocytopenic purpura with fever, thrombocytopenia, microangiopathic hemolysis, renal impairment and neurological dysfunction in the form of confusion and coma. Her clinical syndrome and relevant laboratory parameters improved after she was treated with therapeutic plasma exchange. We compared our observations on this patient with the current literature and concluded that thrombotic thrombocytopenic purpura is a theoretically plausible yet unreported manifestation of hump-nosed viper bite up to this moment. This study also provides an important message for clinicians to look out for this complication in hump-nosed viper bites since timely treatment can be lifesaving.

Viper bites complicate chronic agrochemical nephropathy in rural Sri Lanka

Snakebite is a common occupational health hazard among Sri Lankan agricultural workers, particularly in the North Central Province. Viperine snakes, mainly Russell’s viper envenomation, frequently lead to acute renal failure. During the last two decades, an agrochemical nephropathy, a chronic tubulointerstitial disease has rapidly spread over this area leading to high morbidity and mortality. Most of the epidemiological characteristics of these two conditions overlap, increasing the chances of co-occurrence. Herein, we describe four representative cases of viperine snakebites leading to variable clinical presentations, in patients with chronic agrochemical nephropathy, including two patients presented with acute and delayed anuria. These cases suggest the possibility of unusual manifestations of snakebite in patients with Sri Lankan agrochemical nephropathy, of which the clinicians should be aware. It could be postulated that the existing scenario in the Central America could also lead to similar clinical presentations.