ABSTRACT
Ecuador harbors one of the most diverse Neotropical scorpion faunas, hereby updated to 47 species contained within eight genera and five families, which inhabits the Costa (n= 17), Sierra (n= 34), Oriente (n= 16) and Insular (n= 2) biogeographical regions, corresponding to the western coastal, Andean, Amazonian, and the Galápagos archipelago regions, respectively. The genusTityus Koch, in the family Buthidae, responsible for severe/fatal accidents elsewhere in northern South America and the Amazonia, is represented in Ecuador by 16 species, including T. asthenes, which has caused fatalities in Colombia and Panama, and now in the Ecuadorian provinces of Morona Santiago and Sucumbíos. Underestimation of the medical significance of scorpion envenoming in Ecuador arises from the fact thatCentruroides margaritatus (Gervais) (family Buthidae) andTeuthraustes atramentarius Simon (family Chactidae), whose venoms show low toxicity towards vertebrates, frequently envenom humans in the highly populated Guayas and Pichincha provinces. This work also updates the local scorpion faunal endemicity (74.5 %) and its geographical distribution, and reviews available medical/biochemical information on each species in the light of the increasing problem of scorpionism in the country. A proposal is hereby put forward to classify the Ecuadorian scorpions based on their potential medical importance.
Subject(s)
Animals , Animal Distribution , Ecuador , Scorpions/classificationABSTRACT
Ecuador harbors one of the most diverse Neotropical scorpion faunas, hereby updated to 47 species contained within eight genera and five families, which inhabits the "Costa" (n= 17), "Sierra" (n= 34), "Oriente" (n= 16) and "Insular" (n= 2) biogeographical regions, corresponding to the western coastal, Andean, Amazonian, and the Galápagos archipelago regions, respectively. The genusTityus Koch, in the family Buthidae, responsible for severe/fatal accidents elsewhere in northern South America and the Amazonia, is represented in Ecuador by 16 species, including T. asthenes, which has caused fatalities in Colombia and Panama, and now in the Ecuadorian provinces of Morona Santiago and Sucumbíos. Underestimation of the medical significance of scorpion envenoming in Ecuador arises from the fact thatCentruroides margaritatus (Gervais) (family Buthidae) andTeuthraustes atramentarius Simon (family Chactidae), whose venoms show low toxicity towards vertebrates, frequently envenom humans in the highly populated Guayas and Pichincha provinces. This work also updates the local scorpion faunal endemicity (74.5 %) and its geographical distribution, and reviews available medical/biochemical information on each species in the light of the increasing problem of scorpionism in the country. A proposal is hereby put forward to classify the Ecuadorian scorpions based on their potential medical importance.(AU)
Subject(s)
Animals , Scorpions/anatomy & histology , Animal DistributionABSTRACT
Mediante cromatografía de intercambio catiónico en CM-Sephadex C-25 (16 x 1,1 cm) con buffer acetato de amonio 0,05 M a pH 7, del veneno del escorpión Brachistosternus ehrenbergii fue aislada una proteína con acción tóxica sobre ratones albinos. En este sistema la toxina interactúa con el gel y es eluida al final luego de usar el mismo buffer conteniendo NaCl 0,6M. La toxina fue denominada Be1 y es una proteína básica que constituye el 8,1% de la proteína total del veneno. La pureza de la toxina fue evaluada por electroforesis en condiciones nativas, de acuerdo al método de Reisfeld, y en condiciones denaturantes por el método de Schägger y von Jagow, determinándose que la toxina es una sola cadena polipeptídica de 6,3 kDa. La inoculación de 60 μg de toxina en ratones albinos, vía intraperitoneal, genera la aparición de algunos signos locales como hipersecreción salival, seguido por afección respiratoria, arrastre de las patas posteriores, hasta finalmente al cabo de 2 horas, producir la muerte. Vía intramuscular (7,6 μg), Be1 produce parálisis temporal de la extremidad inoculada. La toxina no tiene actividades de fosfolipasa, proteasa, acetilcolinesterasa ni actividad inhibidora de acetilcolinesterasa.
By means of cationic exchange chromatography on CM-Sephadex C-25 column (16 x 1,1 cm) with ammonium acetate buffer 0,05 M at pH 7, from Brachistosternus ehrenbergii scorpion venom was isolated a protein with toxic activity on mice. In this system the toxin was ligated to gel and was eluated with buffer and NaCl 0,6M. The toxin denominated Be1 and it characterizes to be a basic protein that constitute 8,1% of venom total protein. Toxin purity was evaluated by electrophoresis in natives conditions, according to Reisfeld-method, and denaturants conditions by the Schägger-and-von Jagow-method, the toxin is a single chain polypeptide of 6,3 kDa has been determined. The inoculation of 60 μg toxin on albino mice, intraperitoneal way, produces some local signals as salival hipersecretion followed by respiratory affection, drags hind feet and finally 2 hours after, death. Intramuscular way (7,6 μg) Be1 produces temporal paralysis of the inoculated limb. The toxin has neither phospholipase, nor protease, nor acetylcholinesterase nor acetylcholinesterase inhibitor activity.