A C-type lectin from Bothrops jararacussu venom reprograms endothelial cell biology.

Snake venoms are intricate mixtures of enzymes and bioactive factors that induce a range of detrimental effects in afflicted hosts. Certain Viperids, including Bothrops jararacussu, harbor C-type lectins (CTLs) known for their modulation of a variety of host cellular responses. In this study, we isolated and purified BjcuL, a CTL from B. jararacussu venom and investigated its impact on endothelial cell behavior, contrasting it with human galectin-1 (Gal-1), a prototype member of the galectin family with shared ß-galactoside-binding activity. We found that BjcuL binds to human dermal microvascular endothelial cells (HMECs) in a concentration- and carbohydrate-dependent fashion and reprograms the function of these cells, favoring a pro-inflammatory and pro-coagulant endothelial phenotype. In light of the quest for universal antagonists capable of mitigating the harmful consequences of snake venoms, BjcuL emerges as a promising target to be blocked in order to regulate pathological endothelial cell responses.

cDNA cloning, heterologous expression, protein folding and immunogenic properties of a phospholipase A2 from Bothrops ammodytoides venom.

A mRNA transcript that codes for a phospholipase (PLA2) was isolated from a single venom gland of the Bothrops ammodytoides viper. The PLA2 transcript was cloned onto a pCR®2.1-TOPO vector and subsequently expressed heterologously in the E. coli strain M15, using the pQE30 vector. The recombinant phospholipase was named rBamPLA2_1, and is composed of an N-terminal fusion protein of 16 residues, along with 122 residues from the mature protein that includes 14 cysteines that form 7 disulfide bonds. Following bacterial expression, rBamPLA2_1 was obtained from inclusion bodies and extracted using a chaotropic agent. rBamPLA2_1 had an experimental molecular mass of 15,692.5 Da that concurred with its theoretical molecular mass. rBamPLA2_1 was refolded in in vitro conditions and after refolding, three main protein fractions with similar molecular masses, were identified. Although, the three fractions were considered to represent different oxidized cystine isoforms, their secondary structures were comparable. All three recombinant isoforms were active on egg-yolk phospholipid and recognized similar cell membrane phospholipids to be native PLA2s, isolated from B. ammodytoides venom. A mixture of the three rBamPLA2_1 cystine isoforms was used to immunize a horse in order to produce serum antibodies (anti-rBamPLA2_1), which partially inhibited the indirect hemolytic activity of B. ammodytoides venom. Although, anti-rBamPLA2_1 antibodies were not able to recognize crotoxin, a PLA2 from the venom of a related but different viper genus, Crotalus durissus terrificus, they recognized PLA2s in other venoms from regional species of Bothrops.

Neutralization of "Chaco eagle" (Buteogallus coronatus) serum on some activities of Bothrops spp. venoms.

Several species of reptiles and mammals have components in their sera that can neutralize toxic components present in snake venoms. In this manuscript, we studied the neutralizing capacity of Chaco eagle's (Buteogallus coronatus) serum. This South American bird of prey eats snakes as a regular part of its diet and has anatomical features that protect from snakes' bites. The neutralizing potency of the Chaco eagle's serum was tested on lethal, hemorrhagic, procoagulant, and phospholipase activities of the venom of "yarará grande" (Bothrops alternatus) and on phospholipase activity of "yarará ñata" (Bothrops ammodytoides) venom; both snakes are known to be the prey of Chaco eagle. Sera of crested caracara (Caracara plancus-a scavenger, omnivorous pan-American bird of prey), secretary bird (Saggitarius serpentarius-an omnivorous bird of prey from Africa that can include venomous snakes in its diet), common hen (Gallus gallus), rat (Rattus norvegicus), mouse (Mus musculus), horse (Equus caballus), and dog (Canis lupus familiaris) were also tested to compare the inhibitory capacity of neutralization. To test isologous and xenologous neutralization, sera from Bothrops alternatus and white-eared opossum (Didelphis albiventris), respectively, were used due to their known inhibitory activity on Bothrops venoms. As a control for the neutralization activity, antibothropic antivenom was used. Chaco eagle's serum neutralized hemorrhagic and phospholipasic activity and slightly neutralized the coagulation and the lethal activity of Bothrops spp. venom. The neutralizing capacity was present in the non-immunoglobulin fraction of the serum, which showed components of acidic characteristics and lower molecular weight than IgY, in correspondence with the characteristics of PLA2s and SVMPs inhibitors described in sera from some snakes and mammals. These studies showed that Chaco eagle's serum neutralizes all toxic activities tested at a higher level than sera from animal species in which inhibitors of snake venoms have not been described (p < 0.05), while it is lower or similar in neutralizing capacity to white-eared opossum and B. alternatus sera.

South American snake venoms with abundant neurotoxic components. Composition and toxicological properties. A literature review.

In South America there are three snake genera with predominantly neurotoxic venoms: Crotalus, Micrurus and Hydrophis, which include nine species/subspecies, 97 species and a single marine species, respectively. Although accidents with neurotoxic venoms are less frequent than those with anticoagulant, cytotoxic or necrotic venoms (e.g. from Bothrops), they are of major public health importance. Venoms from genus Crotalus have been extensively studied, while data on the venoms from the other two genera are very limited, especially for Hydrophis. The venoms of North and South American Crotalus species show biochemical and physiopathological differences. The former species cause bothrops-like envenomation symptoms, while the latter mainly have neurotoxic and myotoxic effects, leading to respiratory paralysis and, occasionally, renal failure by myoglobinuria and death, often with no local lesions. Micrurus and Hydrophis also cause neurotoxic envenomations. Many studies have isolated, identified and characterized new enzymes and toxins, thus expanding the knowledge of snake venom composition. The present review summarizes the currently available information on neurotoxic venoms from South American snakes, with a focus on protein composition and toxicological properties. It also includes some comments concerning potential medical applications of elapid and crotalic toxins.

Genetic and toxinological divergence among populations of Tityus trivittatus Kraepelin, 1898 (Scorpiones: Buthidae) inhabiting Paraguay and Argentina.

Envenoming by scorpions in genus Tityus is a public health problem in Tropical America. One of the most medically significant species is Tityus trivittatus, which is known to occur from southwest Brazil to central-northern and eastern Argentina. In this work, we studied the lethality, composition, antigenicity, and enzymatic activity of venom from a T. trivittatus population found further north in urban areas of eastern Paraguay, where it has caused serious envenomation of children. Our results indicate that the population is of medical importance as it produces a potently toxic venom with an LD50 around 1.19 mg/kg. Venom neutralization in preliminary mouse bioassays was complete when using Brazilian anti-T. serrulatus antivenom but only partial when using Argentinean anti-T. trivittatus antivenom. Venom competitive solid-phase enzyme immunoassays and immunoblotting from Argentinean and Paraguayan T. trivittatus populations indicated that antigenic differences exist across the species range. SDS-PAGE showed variations in type and relative amounts of venom proteins between T. trivitattus samples from Argentina and Paraguay. MALDI-TOF mass spectrometry indicated that while some sodium channel toxins are shared, including ß-toxin Tt1g, others are population-specific. Proteolytic activity by zymography and peptide identification through nESI-MS/MS also point out that population-specific proteases may exist in T. trivitattus, which are postulated to be involved in the envenoming process. A time-calibrated molecular phylogeny of mitochondrial COI sequences revealed a significant (8.14%) genetic differentiation between the Argentinean and Paraguayan populations, which appeared to have diverged between the mid Miocene and early Pliocene. Altogether, toxinological and genetic evidence indicate that T. trivitattus populations from Paraguay and Argentina correspond to distinct, unique cryptic species, and suggest that further venom and taxonomic diversity exists in synanthropic southern South American Tityus than previously thought.

Toxicological study of bee venom (Apis mellifera mellifera) from different regions of the province of Buenos Aires, Argentina.

Samples of Apis mellifera mellifera venom from different hives in two regions of the Buenos Aires province and its pool were analyzed for their lethal potency, myotoxic, defibrinogenating, hemolytic and inflammatory-edematizing activity and for the histological alterations they produce in the heart, lungs, kidneys, skeletal muscle and liver of mice. In vitro studies focused on the venom's hemolytic activity in different systems and species (horse, man, sheep and rabbit), the cytotoxicity in cellular lines, and on the proteolytic and coagulant activity in plasma and fibrinogen. Hemolytic activity, either observed in vitro or in vivo, showed similar toxicity levels for all samples. Erythrocytes of different species varied in their sensitivity to the venom pool, equines being the most sensitive and sheep the most resistant to direct hemolytic action. Local and systemic myotoxicity was evidenced by either the elevation of serum creatine kinase and/or histopathological lesions, observed in different muscles. All samples caused significant pathological alterations; pulmonary, cardiac, renal and skeletal muscle lesions were substantive and can be related to the pathophysiological mechanisms of envenomation. The venoms from different apiaries and regions of the Buenos Aires province showed very similar toxicological characteristics. These results suggest that severity of envenomation in case of a swarming could therefore be more related to the number of bees than to the differential toxicity of the venom from different regions of the province. This is the first study on the toxicity and toxicological characteristics of Apis mellifera venom in Argentina.

Paraspecific neutralization of the venom of African species of cobra by an equine antiserum against Naja melanoleuca: a comparative study.

Venoms of snakes belonging to the same Genera tend to share biochemical, toxinological and antigenic characteristics. Accordingly, paraspecific neutralization of venom lethality by experimental antisera and commercial antivenoms has been reported. We studied the spectrum of neutralization of lethality of an experimental monovalent equine antiserum against the strongly neurotoxic African forest cobra (Naja melanoleuca) when tested against venoms of most species of African Naja, both neuro and cytotoxic as described by some authors. We report a comparison of the median lethal doses (LD50) of the venoms and the paraspecific median effective doses (ED50) of the antiserum calculated using three methods: Spearman-Kärber and Probit (currently recommended by the World Health Organization), and non-linear regression. An ample--but not complete--spectrum of paraspecific neutralization of lethality was observed against both spitting and non-spitting species of African Naja with a clearly more efficient neutralization of the more potent venoms, the implications of which are discussed. The median lethal and effective doses calculated by the three methods are remarkably consistent and may warrant consideration of non-linear regression methods for the calculation of venom lethality and antivenom potency by venom/antivenom researchers and producers.

A new venomous scorpion responsible for severe envenomation in Argentina: Tityus confluens.

In Argentina the scorpions of medical importance belong to the genus Tityus (T.), particularly the species T. trivittatus, the only scorpion whose sting is recognized to be associated with severe human envenoming and death. This genus is distributed from the north of the Patagonian region to the center and some provinces in the north of the country. During the period 2003-2006 four children died following scorpion stings, of which one was certainly and three were probably by T. confluens. In 2006, in the province of Tucumán, a girl died by scorpion envenoming and the scorpion responsible for the death, found in her shoe, was T. confluens. We thus studied the toxicity of venom gland homogenates from T. confluens from the provinces of Jujuy and Catamarca, and of crude venom from specimens from Catamarca and the province of La Rioja. The lethal potencies of the telson homogenates were 7.0 and 18.6microg/g for Jujuy and Catamarca, respectively, while the lethal potency of the crude venom was 0.7microg/g. Injected mice showed generalized congestion and hepatic lesions. Pancreatic damage was observed in some animals. Lungs showed congestion and foci of hemorrhage and mild edema. The heart showed injury in the muscular fibers. The venom showed high reactivity against anti-T. trivittatus antivenom and against two anti-T. serrulatus antivenoms. The anti-T. trivittatus antivenom neutralized the lethal activity of T. confluens venom. In addition, the venom reacted very slightly against an anti-Centruroides antivenom. Therefore, the stings of this scorpion must be considered of risk for humans to the same degree as the stings of T. trivittatus.

Characterization of a new polyvalent antivenom (Antivipmyn Africa) against African vipers and elapids.

As a response to the antivenom shortage in Sub-Saharan Africa, evident for well over a decade, we developed a new polyvalent anti-ophidian antivenom (Antivipmyn((R)) Africa) designed for use in the region. We report a detailed characterization of its biochemical composition (protein content and profiling by size-exclusion chromatography and electrophoresis) as well as the specific and para-specific neutralization potencies (as median effective dose in the mouse lethality test). Additionally, we studied the neutralization of hemorrhagic, anti-hemostatic and necrotic activities of Echis ocellatus venom, responsible for a majority of severe envenomations in the continent according to existing epidemiological data. The antivenom is currently under production and has already been employed in the field in a pragmatic Phase III clinical trial in the Republic of Benin. It is a purified lyophilized polyvalent equine F(ab')(2)-based product obtained by immunization with the venoms of eleven species of African snakes of the Genera Echis, Bitis, Naja and Dendroaspis. The criteria for its design are discussed, particularly in terms of the implementation of realistic public health policies targeting mostly rural populations in the continent.

A novel toxin from the venom of the scorpion Tityus trivittatus, is the first member of a new alpha-KTX subfamily.

The first example of a new sub-family of toxins (alpha-KTx20.1) from the scorpion Tityus trivittatus was purified, sequenced and characterized physiologically. It has 29 amino acid residues, three disulfide bridges assumed to adopt the cysteine-stabilized alpha/beta scaffold with a pI value of 8.98. The sequence identities with all the other known alpha-KTx are less than 40%. Its effects were verified using seven different cloned K(+) channels (vertebrate Kv1.1-1.5, Shaker IR and hERG) expressed in Xenopus leavis oocytes. The toxin-induced effects show large differences among the different K(+) channels and a preference towards Kv1.3 (EC50=7.9+/-1.4 nM).

[Distribution of findings of scorpions in Buenos Aires city in the period 2001-2012 and their sanitary implications]. / Distribución de los hallazgos de escorpiones en la Ciudad de Buenos Aires en el período 2001-2012 y sus implicancias sanitarias.

Scorpion stings and their associated mortality increased in the last years in Argentina, with a cumulative record of 73,617 cases and 30 deaths during the period 2001-2012, occurring almost all the deaths in pediatric patients. However, deaths due to severe envenoming by scorpion stings have not been recorded in Buenos Aires city and suburban regions, although the presence of scorpions in this city has been increasingly reported. We studied the temporal and geographical distribution of Tityus trivittatus findings in Buenos Aires city from the database of the Research and Development Area from the National Institute for Production of Biologics of the National Ministry of Health during the period 10/01/2001 to 31/12/2012 in order to correlate these findings with the distribution of health centers in the city. In this period 385 consults with identification of scorpions were recorded. Annual records showed a growing trend. Georeferenced data showed that findings appeared to increase in the surroundings of metro and train stations, mainly at the east of the city with expansion to the west. Although Toxicology services are geographically related to the zones with higher density of finding of scorpions, the accessibility to the centers with antivenom may hinder its application in the recommended time; some measures to avoid possible delays in the application of the treatment are suggested.

En Argentina, las picaduras de alacrán (escorpión) y la mortalidad asociada aumentaron en los últimos años. Durante el período 20012012, se registraron 73 617 accidentes y 30 óbitos, casi todos en pacientes pediátricos. A diferencia de otras latitudes del país, en la Ciudad de Buenos Aires y su Conurbano, no se registraron envenenamientos graves o muertes por estos arácnidos. El objetivo fue describir la distribución temporal y geográfica de los hallazgos de Tityus trivittatus en la Ciudad de Buenos Aires desde el 10/1/2001 al 31/12/2012 y su relación con la distribución de los centros asistenciales. Hubo 385 consultas con identificación de escorpiones. Los registros anuales mostraron una tendencia creciente. El georreferenciamiento mostró áreas con mayor frecuencia de hallazgos y densidad en proximidades de ciertas estaciones de ferrocarril y subterráneos, principalmente al este de la ciudad con expansión hacia el oeste. Si bien los centros con servicios de Toxicología coinciden geográficamente con estas zonas, la accesibilidad a centros que disponen del antiveneno puede dificultar su aplicación en el tiempo recomendado. Se sugieren medidas para prevenir demoras en los tratamientos.

Phase I and pharmacokinetics study of crotoxin (cytotoxic PLA(2), NSC-624244) in patients with advanced cancer.

A Phase I clinical trial was performed on patients with solid tumors refractory to conventional therapy. Crotoxin was administered i.m. for 30 consecutive days at doses ranging from 0.03 to 0.22 mg/m(2). Patients entered the study after providing a written informed consent. Although 26 patients were entered only 23 were evaluated. Reversible, nonlimiting neuromuscular toxicity evidenced as diplopia because of pareses of the external ocular muscles was present in 13 patients. It started at doses of 0.18 mg/m(2) and lasted from 2 to 6 h. These episodes did not require dose adjustment and disappeared in 1-3 weeks of treatment. Three patients experienced palpebral ptosis, nystagmus (grade 2), and anxiety (grade 2-3) at the dose-limiting toxicity of 0.22 mg/m(2). Also at dose-limiting toxicity, 1 patient showed nystagmus (grade 2) and anxiety (grade 3) without evidence of palpebral ptosis. Transient increases (grades 1-3) in the levels of creatinine kinase, aspartate aminotransferase, and alanine transaminase attributed to crotoxin myotoxicity were observed but returned to normal by the last week of treatment. At 0.21 mg/m(2) there was a case of grade-3 anaphylactic reaction on day 31, which required treatment. Hypersensitivity was regarded as an adverse drug-related reaction, and the patient was removed from the protocol. Two patients at different doses (0.12 mg/m(2) and 0.22 mg/m(2)) had sialorrhea. Four patients had asymptomatic transient increase in blood pressure (up to 20 mm Hg) 12 h after the first injection, which lasted 24 h. No treatment was required and toxicity did not reappear. Six patients experienced slight eosinophilia during the first 2 weeks. The maximum tolerated dose was set at 0.21 mg/m(2). Objective measurable partial responses (>50% reduction of tumor mass) were noted in 2 patients treated at 0.21 mg/m(2) and 1 at 0.12 mg/m(2). One patient (at 0.21 mg/m(2)) presented a complete response on day 110. Crotoxin pharmacokinetics showed rapid absorption from the injection site to blood (t(1/2 A) = 5.2 +/- 0.6 min). Plasma concentration reached a peak (C(max) = 0.79 +/- 0.1 ng/ml) at tau(max) = 19 +/- 3 min. The half-life of the distribution (alpha) phase is 22 +/- 2 min. Starting at 1.5 h after injection, the decrease in plasma concentration becomes slower, reaching 14 +/- 3 pg/ml 24 h after injection. The profile is dominated by the elimination (beta) phase with a half-life of 5.2 +/- 0.6 h. Consequently, 24 h after the injection ( approximately 5 half-life) 97% of the product was eliminated. The area under plasma concentration versus time curve was 0.19 +/- 0.05 microg/min/ml. Assuming availability (F) approximately 1, the clearance is C(L) = 26.3 +/- 7 ml/min, and the apparent volume of distribution is V(d) = 12 +/- 3 liter/kg. The recommended dose for a Phase II study is 0.18 mg/m(2).

[Toxicity of venoms from snakes of medical importance in México]. / Toxicidad de venenos de serpientes de importancia médica en México.

The characterization of the toxic activities of snake venoms is necessary to understand the physiopathology of the envenomation and to test the potency of the antivenoms used to treat this pathology. Because of the lack of data on the toxic activities of venoms from Mexican snakes of medical importance, we studied the venoms from Bothrops asper, Athropoides nummifrr, Agkistrodon billineatus, Crotalus durissus durissus, Crotalus basiliscus, Crotalus scutulatus, Crotalus atrox and Micrurus nigrocinctus. The studies performed were: SDS-PAOE, determination of lethal potency, hemorrhagic, necrotizing, coagulation on plasma and fibrinogen, phospholipasic and fibri(noge)nolytic activities. In addition we studied the neutralizing capacity of the toxic activities of an antivenom currently used for the treatment of snakebites in Mexico. The venom from viperids showed important hemorrhagic, necrotizing, coagulative on plasma, prothrombinic, fibrinogenolytic and phospholipase activities. The venoms with the highest lethal potency were those of Micrurus nigrocinctus and Crotalus scutulatus; however, the viperine venom that globally displayed the most potent toxic activities was from Bothrops asper. All the venoms showed toxic activities of similar range to those described for other American venomous snakes. The activity on plasma or fibrinogen varied widely among the different venoms but all displayed capacity to act on the coagulation system. The antivenom tested not only neutralized the lethality B. asper venom but also its other toxic activities.

[Poisoning by bee sting]. / Envenenamiento por picaduras de abeja.

Among the human pathologies produced by venomous animals, bee stings constitute the largest number of accidents in several countries, exceeding the mortality rate caused by other venomous animals such as snakes, spiders or scorpions. The clinical picture after the bee sting may include anaphylaxis or poisoning. The latter is produced by massive attacks and is a serious problem that may put the patient's life at risk. People that are poisoned display hemolysis, rhabdomiolysis and acute renal failure that together with other systemic failures can bring about death. The knowledge of the physiopathological mechanisms involved in the massive attack of bees is crucial for health care professionals as to date we do not have antivenoms with proven clinical efficacy. In this review we include the bee's biological aspects, venom composition and its relation with the occurrence and severity of accidents as well as epidemiological data that can be useful for this type of accidents.

Biochemical and physiological characterization of a new Na(+)-channel specific peptide from the venom of the Argentinean scorpion Tityus trivittatus.

A new peptide with 61 amino acids cross-linked by 4 disulfide bridges, with molecular weight of 6938.12Da, and an amidated C-terminal amino acid residue was purified and characterized. The primary structure was obtained by direct Edman degradation and sequencing its gene. The peptide is lethal to mammals and was shown to be similar (95% identity) to toxin Ts1 (gamma toxin) from the Brazilian scorpion Tityus serrulatus; it was named Tt1g (from T. trivittatus toxin 1 gamma-like). Tt1g was assayed on several sub-types of Na(+)-channels showing displacement of the currents to more negative voltages, being the hNav1.3 the most affected channel. This toxin displays characteristics typical to the ß-type sodium scorpion toxins. Lethality tests and physiological assays indicate that this peptide is probably the most important toxic component of this species of scorpion, known for causing human fatalities in the South American continent.

Disulfide bridges and blockage of Shaker B K(+)-channels by another butantoxin peptide purified from the Argentinean scorpion Tityus trivittatus.

A peptide was isolated from the venom of the scorpion Tityus trivittatus. It is an isoform of the toxin TsTX-IV earlier described [Toxicon 37 (1999) 651] and identical to butantoxin [Arch. Biochem. Biophys. 379 (2000) 18], both isolated from the Brazilian scorpion Tityus serrulatus. This newly characterized peptide contains 40 amino acid residues with a molecular mass of [M+H(+)] 4507.0, cross-linked by four disulfide bridges, made between the cysteine pairs: Cys2-Cys5, Cys10-Cys31, Cys16-Cys36 and Cys20-Cys38. It blocks in a completely reversible manner the Shaker B K(+)-channels, with a K(d) around 660nM. It belongs to the sub-family 12 and it is now being classified as alpha-KTx 12.2.

Epidemiological and clinical aspects of scorpionism by Tityus trivittatus in Argentina.

This is a descriptive study of epidemiological and clinical aspects of stings caused by the scorpion Tityus trivittatus in Argentina. We analyzed 511 cases recorded from different health centers in 22 provinces. Most accidents took place during the period November-April (76%), in or nearby houses (86%). Over 50% of the accidents involved children and teenagers. Envenomation by T. trivittatus was mainly characterized by local symptoms: pain (85%), edema (26.6%), burning sensation (24.7%), erythema (20.7%), local hyperthermia (13.1%), paresthesia (9.8%) and general manifestations such as vomiting (25%), paleness (18.8%), headache (11.4%) and sweating (8.2%). Neurological, cardiovascular and respiratory disorders were uncommon. Almost 90% of the injured people got treated with specific antivenom within 2 h, 6% were treated 2-h after the accident and only 2 people were treated 12 or more hours after being stung. The global mortality recorded was 6 per 1000 cases. Scorpionism in Argentina is a public health problem under control due to the relatively low incidence and the accessibility of specific antivenom.

[Poisoning by spiders of Loxosceles genus]. / Envenenamiento por arañas del género Loxosceles.

Despite the great number of spiders in the world, only a small group of them is capable of producing death in humans. In Argentina, there are only three of the four genera of spiders considered of high risk to humans: Latrodectus is present in rural areas, Phoneutria is restricted to small regions while Loxosceles is distributed throughout the country. Accidents by Loxosceles represent around 4% of the total number produced by venomous animals in Argentina. The bite is accidental and may produce considerable local necrosis with scar formation and ulcers of slow and difficult healing that may require surgical repair. Some bitten people may suffer from intravascular hemolysis, disseminated coagulation and acute renal insufficiency leading to death. Despite the great number of studies performed on Loxosceles venoms, at present, the physiopathological course of poisoning is not clear and there is not common criteria for its treatment. In this review, biological and epidemiological data of this spider are described as well as the venom composition and the possible participation of its components in the poisoning. These data provide biological and biochemical tools to understand the course of poisoning and to have better criteria for the treatment and prevention of these accidents and their complications.

Expansión de la distribución de escorpiones del género Tityus C. L. Koch 1836 en Argentina: Implicancias sanitarias / Expansion of the distribution of scorpions of the genus Tityus C. L. Koch 1836 in Argentina: Implications in public health

Se ha observado la presencia de especies de Tityus en diferentes regiones del país, en las cuales su presencia no había sido comunicada previamente: 1- Tityus bahiensis en las provincias de Entre Ríos y Buenos Aires, en esta última en la localidad de Lanús y en San Clemente del Tuyú, y 2- Tityus confluens en la Ciudad Autónoma de Buenos Aires (CABA) y en la provincia de Buenos Aires en las localidades de Pilar, La Plata, Mar del Plata y Bahía Blanca. Estos hallazgos modifican el mapa de la distribución de escorpiones de importancia sanitaria en Argentina por lo que ante la picadura de escorpiones deben considerarse estos nuevos hallazgos. Esto es especialmente importante en el ámbito de la CABA y la provincia de Buenos Aires, en donde la enorme mayoría de los accidentes por escorpiones han sido causados por T. trivittatus y en donde ahora, al menos en algunas de sus regiones se pueden encontrar T. confluens y T. bahiensis. Se discuten posibles razones de esta nueva distribución así como la ocurrencia de accidentes graves en zonas donde no ocurrían históricamente y de sus posibles causas. En base a los casos graves producidos en los últimos tiempos y a este nuevo mapa de distribución, se hace énfasis en la necesidad de capacitación al personal de salud en general y de los médicos de guardia y terapistas en particular, para tratar adecuadamente los accidentes por escorpiones.

Several species of Tityus have been described in regions of Argentina where their presence had not been previously described. These are: 1- Tityus bahiensis in the provinces of Entre Ríos and Buenos Aires (in the localities of Lanús and San Clemente del Tuyú), and 2- Tityus confluens in the city of Buenos Aires and in the province of Buenos Aires in the localities of Pilar, La Plata, Mar del Plata and Bahía Blanca. These findings modify the distribution map of scorpions of sanitary importance in Argentina, reason for which this new distribution must be considered when facing a scorpion sting. This is especially important in the city of Buenos Aires and the province of Buenos Aires, where most of the accidents by scorpions are caused by Tityus trivittatus, and where at least in some of their regions, T. confluens or T. bahiensis can be found at present. The possible reasons of this new distribution, as well as the possible causes for the occurrence of severe envenomations in regions where these were not observed historically, are discussed. Based on the severe envenomations observed and on this new distribution map, emphasis is placed on the need to capacitate health personnel in general and intensivists or critical care physicians in particular to adequately treat scorpion accidents.