Linking toxicity and predation in a venomous arthropod: the case of Tityus fuhrmanni (Scorpiones: Buthidae), a generalist predator scorpion

Background: Scorpions are arachnids that have a generalist diet, which use venom to subdue their prey. The study of their trophic ecology and capture behavior is still limited compared to other organisms, and aspects such as trophic specialization in this group have been little explored. Methods: In order to determine the relationship between feeding behavior and venom toxicity in the scorpion species Tityus fuhrmanni, 33 specimens were offered prey with different morphologies and defense mechanisms: spiders, cockroaches and crickets. In each of the experiments we recorded the following aspects: acceptance rate, immobilization time and the number of capture attempts. The median lethal dose of T. fuhrmanni venom against the three different types of prey was also evaluated. Results: We found that this species does not have a marked difference in acceptance for any of the evaluated prey, but the number of capture attempts of spiders is higher when compared to the other types of prey. The immobilization time is shorter in spiders compared to other prey and the LD50 was higher for cockroaches. Conclusions: These results indicate that T. fuhrmanni is a scorpion with a generalist diet, has a venom with a different potency among prey and is capable of discriminating between prey types and employing distinct strategies to subdue them.(AU)

Linking toxicity and predation in a venomous arthropod: the case of Tityus fuhrmanni (Scorpiones: Buthidae), a generalist predator scorpion

Abstract Background: Scorpions are arachnids that have a generalist diet, which use venom to subdue their prey. The study of their trophic ecology and capture behavior is still limited compared to other organisms, and aspects such as trophic specialization in this group have been little explored. Methods: In order to determine the relationship between feeding behavior and venom toxicity in the scorpion species Tityus fuhrmanni, 33 specimens were offered prey with different morphologies and defense mechanisms: spiders, cockroaches and crickets. In each of the experiments we recorded the following aspects: acceptance rate, immobilization time and the number of capture attempts. The median lethal dose of T. fuhrmanni venom against the three different types of prey was also evaluated. Results: We found that this species does not have a marked difference in acceptance for any of the evaluated prey, but the number of capture attempts of spiders is higher when compared to the other types of prey. The immobilization time is shorter in spiders compared to other prey and the LD50 was higher for cockroaches. Conclusions: These results indicate that T. fuhrmanni is a scorpion with a generalist diet, has a venom with a different potency among prey and is capable of discriminating between prey types and employing distinct strategies to subdue them.

MS/MS analysis of four scorpion venoms from Colombia: a descriptive approach

Background: Scorpions are widely known for the neurotoxic effects of their venoms, which contain peptides affecting ionic channels. Although Colombia is recognized for its scorpion diversity, only a few studies are available describing the venom content. Methods: In this descriptive study, we analyzed the MS/MS sequence, electrophoretic and chromatographic profile linked to a bioinformatics analysis of the scorpions Chactas reticulatus (Chactidae), Opisthacanthus elatus (Hormuridae), Centruroides edwardsii (Buthidae) and Tityus asthenes (Buthidae) from Colombia. Results: Each scorpion showed a specific electrophoretic and chromatographic profile. The electrophoretic profiles indicate the presence of high molecular mass compounds in all venoms, with a predominance of low molecular mass compounds in the Buthidae species. Chromatographic profiles showed a similar pattern as the electrophoretic profiles. From the MS/MS analysis of the chromatographic collected fractions, we obtained internal peptide sequences corresponding to proteins reported in scorpions from the respective family of the analyzed samples. Some of these proteins correspond to neurotoxins affecting ionic channels, antimicrobial peptides and metalloproteinase-like fragments. In the venom of Tityus asthenes, the MSn analysis allowed the detection of two toxins affecting sodium channels covering 50% and 84% of the sequence respectively, showing 100% sequence similarity. Two sequences from Tityus asthenes showed sequence similarity with a phospholipase from Opisthacanthus cayaporum indicating the presence of this type of toxin in this species for the first time. One sequence matching a hypothetical secreted protein from Hottentotta judaicus was found in three of the studied venoms. We found that this protein is common in the Buthidae family whereas it has been reported in other families - such as Scorpionidae - and may be part of the evolutionary puzzle of venoms in these arachnids. Conclusion: Buthidae venoms from Colombia can be considered an important source of peptides similar to toxins affecting ionic channels. An interesting predicted antimicrobial peptide was detected in three of the analyzed venoms.(AU)

Efecto citotóxico de fosfolipasas A2 del veneno de Crotalus durissus cumanensis de Colombia / Cytotoxic effect of A2 phospholipases of the venom of Crotalus durissus cumanensis from Colombia / Efeito citotóxico da fosfolipase A2 do veneno de Crotalus durissus cumanensis da Colômbia

Introducción. Los venenos de serpientes representan una fuente importante de proteínas y péptidos, los cuales exhiben diversas actividades biológicas, tales como antibacterianas, antiparasitarias, antivi-rales, antitumorales, antifúngicas y contra la agregación plaquetaria, entre otras.Las fosfolipasas A2 presentes en los venenos de serpientes son las proteínas más estudiadas en estos modelos. Se ha demostrado que las fosfolipasas A2, activas e inactivas, poseen actividad catalítica contra células tumorales. Objetivo. Aislar, purificar y caracterizar la fosfolipasa A2 del veneno de Crotalus durissus cumanensis para evaluar su actividad antitumoral in vitro. Materiales y métodos. El aislamiento, la purificación y la identificación de la crotoxina B se hizo mediante la cromatografía de exclusión molecular, la cromatografía líquida de alto rendimiento de fase inversa (Reversed Phase High-Performance Liquid Chromatography, RP-HPLC) y la espectrometría de masas. El efecto citotóxico sobre células tumorales (K562) y células normales (células mononucleares de sangre periférica) se determinó utilizando la técnica de MTT. Resultados. La separación y posterior identificación de la crotoxina B del veneno de C. d. cumanensis de Colombia, permitieron evidenciar que esta fosfolipasa A2 posee efecto citotóxico sobre las células mononucleares de sangre periférica con una dosis de 18,23 ± 0,57 µg/ml, mientras que, para las células K562, fue de 2,34 ± 0,199 µg/ml. Conclusiones. Los resultados sugieren la posibilidad de utilizar la crotoxina B aislada del veneno de C. d. cumanensis como un posible recurso terapéutico para su aplicación en humanos.

Introduction. Snake venoms are an important source of proteins and peptides, which display various biological activities such as antibacterial, antiparasitic, antiviral, antitumor, antifungal and against platelet aggregation, among others.Phospholipases A2 present in snake venoms are the most studied proteins in these models. Active and inactive A2 phospholipases have been shown to possess catalytic activity against tumor cells. Objective. To isolate, purify and characterize the phospholipase A2 of the venom of Crotalus durissus cumanensis to evaluate its in vitro antitumor activity. Materials and methods. Isolation, purification and identification of crotoxin B was done with Size Exclusion Chromatography, Reversed Phase High-Performance Liquid Chromatography, RP-HPLC, and Mass Spectrometry. The cytotoxic effect on tumor cells (K562) and normal cells (peripheral blood mononuclear cells) was determined using the MTT technique. Results. The separation and subsequent identification of crotoxin B, found in the venom of C. d. cumanensis from Colombia, showed that this phospholipase A2 has a cytotoxic effect on peripheral blood mononuclear cells at a dose of 18.23 ± 0.57 µg / ml, whereas for K562 cells, it was 2.34 ± 0.199 µg/ml Conclusions. The results suggest the use of crotoxin B, isolated from the venom of C. d. cumanensis, as a possible therapeutic resource for human application.

Introdução. Os venenos da serpentes constituem uma importante fonte de proteínas e péptidos, os quais exibem várias actividades biológicas, tais como agentes antibacterianos, antiparasitárias, antivi-rais, antitumorais, antifúngicas e contra a agregação de plaquetas, entre outros. As fosfolipases A2 presentes no veneno da serpentes são as proteínas mais estudadas nestes modelos. Tem sido demostrado que as fosfolipases A2, activas e inactivas, possuem actividade catalítica contra células tumorais. Objetivo. Isolar, purificar e caracterizar a fosfolipase A2 do veneno da Crotalus durissus cumanensis para avaliar a sua actividade anti-umoral in vitro. Materiais e métodos. O isolamento, a purificação e identificação da crotoxina B foi realizada por cromatografia de exclusão molecular, cromatografia líquida de alta eficiência de fase reversa (Reversed Phase High-Performance Liquid Chromatography, RP-HPLC) e espectrometria de massa. O efeito cito-tóxico sobre células tumorais (K562) e células normais (células mononucleares do sangue periférico) foi determinada usando a técnica de MTT. Resultados. A Separação e subsequente identificação da crotoxina B do veneno da C. d. cumanensis da Colômbia, permitiu constatar que esta fosfolipase A2 tem um efeito citotóxico em células mono-nucleares de sangue periférico, com uma dose de 18,23 ± 0,57 µg/ ml, enquanto que para as células K562, foi 2,34 ± 0,199 ug/ml. Conclusões. Os resultados sugerem a possibilidade de utilizar crotoxina B isolada a partir do veneno da C. d. cumanensis como recurso para o potencial uso terapêutico em humanos.

DISTRIBUCIÓN DE Centruroides edwardsii (GERVAIS, 1843) EN EL DEPARTAMENTO EN ANTIOQUIA, COLOMBIA / Distribution of Centruroides edwardsii (GERVAIS, 1843) in the Antioquia Province, Colombia

Se reporta la distribución de Centruroides edwardsii (Gervais, 1843) para el departamento de Antioquia, y el área urbana de su capital político-administrativa, la ciudad de Medellín, Colombia, con base a material depositado en la colección del Serpentario de la Universidad de Antioquia (SUA). Se estableció dimorfismo sexual en C. edwardsii, mediante análisis de escalamiento multidimensional y el modelo ANOSIM, encontrando que los machos son más grandes que las hembras. Se reporta para el área zona centro y nor-oriental de Medellín una importante colonia de este escorpión, hecho de gran relevancia debido a la importancia clínica de este escorpión. Se amplía además el rango de distribución desde el nivel del mar hasta los 2200 m s.n.m.

We report the distribution of the Centruroides edwardsii (Gervais, 1843) in the Antioquia province, and the urban area of the capital, Medellín, Colombia, based in the material examined in the collection of the Universidad de Antioquia Serpentarium (SUA). A sexual dimporphism were established in C. edwardsii when a multidimensional analysis and using for the statistical significance the ANOSIM model were performed founding higher sizes in males. An important colony of this scorpion is reported in the central and nor-oriental zone of Medellín, aspect that is very relevant since this scorpion is considered clinically relevante. The species distribution rank is also expanded from the sea level, up to 2200 m a.s.l.

Accidente ofídico en animales de pastoreo: acercamiento epidemiológico, clínico y de manejo / Ophidic Accident in Grazing Animals: Epidemiological, Clinical and Handling Approach / Acidente ofídico em animais de pastoreio: aproximação epidemiológica, clínica e de manejo

En animales de pastoreo, el reporte de accidentes ofídicos es muy bajo y, además, presenta un amplio subregistro. A pesar de esto, es de gran utilidad conocer la incidencia de estos accidentes, pues son de gran importancia por las pérdidas económicas que pueden causar en el sector pecuario. Los accidentes por serpientes venenosas, tanto de la familia Viperidae como Elapidae, en caballos y ganado vacuno son frecuentes en muchos lugares del mundo, debido al aumento en la destinación de las tierras para la actividad ganadera. Colombia no es ajena a ello; sin embargo, el registro de este tipo de accidentalidad es muy bajo. En los diferentes reportes de accidentes ofídicos en animales, se ha observado que las principales manifestaciones sistémicas están caracterizadas por complicaciones cardiacas, hemodinámicas y neurotóxicas. Igualmente, se observan efectos locales, los cuales se caracterizan por presencia de hemorragias locales, edema y necrosis. El tratamiento específico utilizado en los accidentes por serpientes es la seroterapia, que consta de inmunoglobulinas G (Sueros IgG) completas o fraccionadas (Faboterápicos Fab o Fab2), específicas para un género o especie.

The report of ophidic accidents in grazing animals is very low, and it is also widely under recorded. In spite of this, it is of great use to know the incidence of these accidents, as they are very important due to the economic loss they may cause to the livestock sector. Accidents caused by poisonous snakes from the Viperidae and Elapidae families in horses and in cattle are very frequent in many parts of the world, given the increase in land destination for livestock. Colombia's case is no different; however, the report of this type of accidents is very low. In the different reports of ophidic accidents in animals, it is observed that the main systemic manifestations are characterized by cardiac, hemodynamic and neurotoxic complications. Likewise, local effects are observed, mainly characterized by the presence of local bleeding, edema and necrosis. The specific treatment used in accidents caused by snakes is serotherapy, which consists of full or fractional immunoglobulin G (IgG Serum) (Fabotherapics Fab or Fab2), specific for a gender or a species.

Em animais de pastoreio, o número de acidentes ofídicos reportado é muito baixo e, além disso, apresenta um amplo sub-registro. Apesar disto, é de grande utilidade conhecer a incidência destes acidentes, pois são de grande importância pelas perdas econômicas que podem causar no setor pecuário. Os acidentes por serpentes venenosas, tanto da família Viperidae como Elapidae, em cavalos e gado são frequentes em muitos lugares do mundo, devido ao aumento na destinação das terras para a atividade pecuarista. A Colômbia não é alheia a isso; porém, o registro deste tipo de acidentalidade é muito bajo. em os diferentes reportes de acidentes ofídicos em animais, se ha observado que as principais manifestações sistêmicas estão caracterizadas por complicações cardíacas, hemodinâmicas e neurotóxicas. Igualmente, se observam efeitos locais, os quais se caracterizam por presença de hemorragias locais, edema e necrose. O tratamento específico utilizado nos acidentes por serpentes é a seroterapia, que consta de imunoglobulinas G (Soros IgG) completas ou fracionadas (Faboterápicos Fab ou Fab2), específicas para um gênero ou espécie.