Yellow Scorpion Research Articles

Antepartum fetal death following a yellow scorpion sting

Scorpion envenomation in pregnant victims has been scarcely studied. We would like to suggest an association between yellow scorpion sting during the third trimester of pregnancy and adverse fetal outcome. The particular deleterious mechanism of scorpion venom has not been elucidated yet.

Hemograma de cães submetidos ao envenenamento experimental por Tityus serrulatus

Avaliou-se o hemograma de 12 cães adultos, saudáveis (14,2±5,4kg) após a inoculação de veneno do escorpião amarelo (Tityus serrulatus). Os animais foram distribuídos em dois grupos (G), com seis em cada: os do GI foram usados como controle e receberam 0,5mL de salina tamponada com fosfato (PBS) por via subcutânea (SC) na face medial da coxa esquerda (FMCE), e os do GII receberam veneno liofilizado do T. serrulatus (250µg/kg) diluído em PBS por via SC na FMCE. Foram realizadas colheitas de sangue com anticoagulante EDTA a 10% antes da inoculação do veneno (T0) e após 2h, (T1), 6h (T2), 12h (T3), 24h (T4), 48h (T5) e 72h (T6), para contagem de eritrócitos, leucócitos e plaquetas em aparelho contador eletrônico e esfregaços sanguíneos para contagem diferencial de leucócitos. Houve aumento significativo (P<0,05) dos valores de eritrócitos, volume globular e hemoglobina 2h e 6h após o envenenamento, devido à contração esplênica decorrente da dor local causada pelo veneno e pela liberação de catecolaminas. Foi observada leucocitose por aumento significativo (P<0,05) de neutrófilos e linfócitos 2h e 6h após o envenenamento. Concluiu-se que o veneno de Tityus serrulatus na dose de 250µg/kg, é capaz de aumentar os valores do eritrograma e do leucograma dos cães, provavelmente devido à dor local, com liberação de catecolaminas.

Tityus serrulatus Hypotensins: A new family of peptides from scorpion venom

Using a proteomic approach, a new structural family of peptides was put in evidence in the venom of the yellow scorpion Tityus serrulatus. Tityus serrulatus Hypotensins (TsHpt) are random-coiled linear peptides and have a similar bradykinin-potentiating peptide (BPP) amino acid signature. TsHpt-I (2.7 kDa), the first member of this family, was able to potentiate the hypotensive effects of bradykinin (BK) in normotensive rats. Using the C-terminal of this peptide as a template, a synthetic analog peptide (TsHpt-I [17–25]) was designed to held the BK-potentiating effect. A relevant hypotensive effect, independent on BK, was also observed on both TsHpt (native and synthetic). To better evaluate this hypotensive effect, we examined the vasorelaxation of aortic rings from male Wistar rats and the peptides were able to induce endothelium-dependent vasorelaxation dependent on NO release. Both TsHpt could not inhibit ACE activity. These peptides appear to exert their anti-hypertensive effect through NO-dependent and ACE-independent mechanisms.

Treatment of yellow scorpion (Leiurus quinquestriatus) sting: A case report

ObjectivesTo report the treatment given to a 26-year-old Air Force medic who was stung twice by a yellow scorpion (Leiurus quinquestriatus) while stationed in Iraq and to describe the problems and issues related to the use of the scorpion antivenin. Patient caseThe patient presented 2 hours after envenomation to the local military treatment facility, where she was minimally symptomatic initially. Shortness of breath and anxiety developed, and the patient was sedated, intubated, and evacuated to a large Air Force medical facility for more advanced care. Vasopressor support was required during flight. At the medical facility, antivenin was administered, and the patient’s cardiac condition was stabilized with norepinephrine drip, mild hydration, and vasopressor support. A second dose of antivenin diluted in sodium chloride and further pressor support were required. ST-segment depression eventually resolved, and the patient was gradually taken off norepinephrine and extubated. She recovered fully within 2 weeks and returned to active duty. DiscussionBecause the antivenin used is not licensed by the Food and Drug Administration, informed consent was needed; however, it could not be obtained because the patient was unconscious, intubated, and in a life-or-death situation. Antivenin selection is based on the species of scorpion and symptom severity; therefore, the scorpion should be, with great care, killed for identification. In the military setting, inventory control, storage, and accountability are vital issues surrounding antivenin use, and these are discussed in this article. ConclusionImmediate action and effective communication, along with timely antivenin administration and well-equipped intensive care facilities, were integral in saving the life of this victim of a yellow scorpion envenomation. All level 3 facilities in Southwest Asia must be familiar with ordering, administering, and documenting this antivenin because it is difficult to obtain and infrequently available.

Amelioration of the cardiovascular manifestations of the yellow scorpion Leiurus quinquestriatus envenomation in rats by red grape seeds proanthocyanidins

The study attempts to determine the involvement of oxidative stress in cardiovascular manifestations during Leiurus quinquestriatus quinquestriatus ( LQQ) scorpion envenomation and to examine the possible protective role of red grape seed proanthocyanidins (GSP) against such effects. Lethality studies conducted in mice demonstrated a significant ( p<0.01) protection of GSP against venom lethality. Pretreatment with GSP (200 mg kg −1, p.o., 10 days) prior to venom injection (350 μg kg −1, s.c.) resulted in a significant decrease in percent mortality as well as in significant prolongation of the animal's survival time ( p<0.01). Monitoring the cardiovascular effects elicited by venom injection in anesthetized rats revealed a marked protection of GSP against the increase in mean arterial blood pressure evoked by LQQ venom. Moreover, pretreatment with GSP reduced the characteristic signs of conduction defects, myocardial ischemia, and infarction observed by venom injection. Biochemical analyses showed that scorpion envenomation caused significant ( p<0.001) elevation in serum lactate dehydrogenase as well as creatine kinase-MB activities. Such elevation was ameliorated by GSP ( p<0.001). Oxidative stress parameters revealed that scorpion venom significantly increased ( p<0.001) the level of lipid peroxidative damage in cardiac tissues and reduced the activity of both glutathione reductase and glutathione peroxidase enzymes in cardiac tissues ( p<0.05). In the meantime, GSP offered significant protection against lipid peroxidative damage ( p<0.05) and enhanced cardiac glutathione reductase activity ( p<0.001). In summary, the current study demonstrates that pretreatment with GSP offers significant protection against LQQ envenomation possibly via enhancement of the antioxidant defense systems.

Notas sobre a ocorrência de Tityus serrulatus Lutz &amp; Mello, 1922 (Scorpiones, Buthidae) no oeste do Rio Grande do Sul, Brasil

O escorpião amarelo Tityus serrulatus é registrado pela primeira vez para oeste do Rio Grande do Sul. Foram coletados dois espécimes no município de Uruguaiana (29° 45' 23'' S e 57° 05' 37'' W) em junho de 2006. A ocorrência dos espécimes de T. serrulatus no Rio Grande Sul representa um aumento de 2.127 km em sua área de distribuição conhecida.

Mechanoreceptive function of pectines in the Brazilian yellow scorpion Tityus serrulatus: perception of substrate-borne vibrations and prey detection

Environment perception by scorpions is an issue of great interest, and there is controversy about the use of pectines in this function. This paper investigates the mechanoreceptive function of pectines of the yellow scorpion Tityus serrulatus. The study was conducted in laboratory conditions from July 2003 to July 2004. Ninety females were maintained in six terraria (N = 15). Three of them were named “control” group (intact pectines) and the others “treatment” group (pectines covered with paraffin). Three experimental tests (an ethogram, a test of prey detection and a test of perception of substrate-borne vibrations) were performed to compare skills of animals with and without blocked pectines. The ethogram showed that treated individuals significantly reduced their exploratory activities, spent more time resting, and aggregated more than the control ones. Prey detection tests showed that the blocking of pectines made the yellow scorpions inefficient to detect and capture prey. Vibration tests showed that animals with blocked pectines also did not respond to the vibrations produced in the substrate, whereas the opposite occurred with the control group. These results suggest a mechanoreceptive function for T. serrulatus pectines, and show that the detection of ground vibrations by these structures is important for prey perception and orientation in the Brazilian yellow scorpion.

A novel depolarizing activity of scorpion venom fraction M1 due to activation of skeletal muscle nicotinic receptors

A depolarizing activity following interaction with nicotinic acetylcholine receptors (nAchRs) in skeletal muscle cells, was observed for the first time in the non-toxic venom fraction (M1) of the yellow scorpion Buthus occitanus tunetanus (Bot). The effects of M1 fraction were tested on cultured rat myotubes by recording changes in [Ca 2+]i. When applied, M1 (10 μg/mL) induced a transient increase of [Ca 2+] i which could be blocked by a prior application of α-Bungarotoxin ( α-Bg-Tx).

Construction of concept maps as tool for Biochemistry learning

The use of concept maps on the teaching of sciences has been object of worldwide research with different purposes: to detect the previous knowledge of the students on certain topics or to evaluate learning, among others. Based on Ausubel´s cognitive psychology, concept maps assume that the learning is accomplished by assimilation of new concepts and propositions to the students´ cognitive structure, contributing to establish links between the previous and new knowledge. It is especially interesting on the approach of interdisciplinary issues, as many studied in Biochemistry.The relevance of the use of concept maps on biochemistry learning was evaluated on a thirty-hour undergraduation optional course, with interdisciplinary topics, which are not usually included on introductory Biochemistry courses. The course Biochemistry of Animal Venoms was structured in seven module where the biochemical action mechanisms of the venoms of Crotalus sp (south american rattlesnake), Bothrops sp (jararaca), Loxosceles sp (brown spider), Tityus sp (yellow scorpion), Phoneutria sp (armed spider), Apis mellifera (honey bee) and Latrodectus sp (black widow)were discussed. The students worked in small groups and, at each module, there were (1) an oriented study, guided by questions, texts and schemes, supervised by the teachers, (2) the construction of individual concept maps, where the local and systemic effects of the venoms should be predicted by their biochemical composition and (3) the construction of a new map by the group, incorporating the information of the individual maps. The difficulty level of these tasks was gradually increased throughout the course, with lesser time to carry out the tasks, lesser assistance during the oriented study and even lesser information on the venom effects.The course assessment was given by the number, quality and correction of the concepts relationship present in the concept maps, through a questionnaire and by the teachers’ observation. The concept maps produced exceeded the expectation, being gradually more complex at each module. The answers to the questionnaire, in a 1 to 5 scale, showed that the course answered the students’ expectations (4,3), that the topics chosen were satisfactory (4,4) and that the students recommend the course to colleagues (4,6). Besides, the majority agreed that the concept maps improved the learning of the course content (4,5) and that this methodology should be adopted in other courses and disciplines.

Selection of environmental temperature by the yellow scorpion Tityus serrulatus Lutz &amp; Mello, 1922 (Scorpiones, Buthidae)

The preferred temperature of the yellow scorpion Tityus serrulatus was investigated since its dispersion is a matter of concern. Adult T. serrulatus, weighing 1.24 + 0.20 g (mean + sd) and with a standard length of 59.3 + 2.5 mm, were used. A metallic corridor (120 cm long, 5 cm large and 10 cm high) with thermal gradient ranging from 0°C to 40°C was used. Tityus serrulatus chose and stayed in temperatures ranging from 14°C to 38°C when safe conditions were offered (dark and thigmotactic stimuli). The number of animals that remained in the 11°C-20°C, 21°C-30°C, and 31°C-40°C temperature zones were 8, 8, and 9, respectively. The chi-square test (degree of freedom = 2) showed that differences were not significant (p>0.05). Some animals moved to lower temperature areas (less than 8°C) when the corridor was completely illuminated and thigmotactic stimuli were absent, which led the animals to present a torpor state. It is concluded that T. serrulatus does not select a specific environmental temperature. Associated with the capacity of temporally surviving at low temperatures, this species seems to be highly adaptable to different thermal zones.

Structure–activity relationship of an α-toxin Bs-Tx28 from scorpion ( Buthus sindicus) venom suggests a new α-toxin subfamily

Scorpion venoms are among the most widely known source of peptidyl neurotoxins used for callipering different ion channels, e.g., for Na +, K +, Ca + or Cl −. An α-toxin (Bs-Tx28) has been purified from the venom of scorpion Buthus sindicus, a common yellow scorpion of Sindh, Pakistan. The primary structure of Bs-Tx28 was established using a combination of MALDI-TOF-MS, LC-ESI-MS, and automated Edman degradation analysis. Bs-Tx28 consists of 65 amino acid residues (7274.3 ± 2Da), including eight cysteine residues, and shows very high sequence identity (82–94%) with other long-chain α-neurotoxins, active against receptor site-3 of mammalian (e.g., Lqq-IV and Lqh-IV from scorpions Leiurus sp.) and insect (e.g., BJα-IT and Od-1 from Buthotus judaicus and Odonthobuthus doriae, respectively) voltage-gated Na + channels. Multiple sequence alignment and phylogenetic analysis of Bs-Tx28 with other known α- and α-like toxins suggests the presence of a new and separate subfamily of scorpion α-toxins. Bs-Tx28 which is weakly active in both, mammals and insects (LD 50 0.088 and 14.3 μg/g, respectively), shows strong induction of the rat afferent nerve discharge in a dose-dependent fashion (EC 50 = 0.01 μg/mL) which was completely abolished in the presence of tetrodotoxin suggesting the binding of Bs-Tx28 to the TTX-sensitive Na +-channel. Three-dimensional structural features of Bs-Tx28, established by homology modeling, were compared with other known classical α-mammal (AaH-II), α-insect (Lqh-αIT), and α-like (BmK-M4) toxins and revealed subtle variations in the Nt-, Core-, and RT-CT-domains (functional domains) which constitute a “necklace-like” structure differing significantly in all α-toxin subfamilies. On the other hand, a high level of conservation has been observed in the conserved hydrophobic surface with the only substitution of W43 (Y43/42) and an additional hydrophobic character at position F40 (L40/A/V/G39), as compared to the other mentioned α-toxins. Despite major differences within the primary structure and activities of Bs-Tx28, it shares a common structural and functional motif (e.g., transRT- farCT) within the RT-CT domain which is characteristic of scorpion α-mammal toxins.

Renal effects and vascular reactivity induced by Tityus serrulatus venom

Tityus serrulatus, popularly known as yellow scorpion, is one of the most studied scorpion species in South America and its venom has supplied some highly active molecules. The effects of T. serrulatus venom upon the renal physiology in human showed increased renal parameters, urea and creatinine. However, in perfused rat kidney the effects were not tested until now. Isolated kidneys from Wistar rats, weighing 240–280 g, were perfused with Krebs–Henseleit solution containing 6% (g weight) of previously dialysed bovine serum albumin. The effects of T. serrulatus venom were studied on the perfusion pressure (PP), renal vascular resistance (RVR), urinary flow (UF), glomerular filtration rate (GFR), sodium tubular transport (%TNa +), potassium tubular transport (%TK +) and chloride tubular transport (%TCl −). Tityus serrulatus venom (TsV; 10 μg/mL) was added to the system 30 min after the beginning of each experiment ( n=6). This 30 min period was used as an internal control. The mesenteric bed was perfused with Krebs solution kept warm at 37 °C by a constant flow (4 mL/min), while the variable perfusion pressure was measured by means of a pressure transducer. The direct vascular effects of TsV (10 μg/mL/min; n=6), infused at a constant rate (0.1 mL/min), were examined and compared to the infusion of the vehicle alone at the same rate. TsV increased PP (PP 30′=127.8±0.69 vs PP 60′=154.2±14 mmHg*, * p<0.05) and RVR (RVR 30′=6.29±0.25 vs RVR 60′=8.03±0.82 mmHg/mL g −1 min −1*, * p<0.05), decreased GFR (GFR 30′=0.58±0.02 vs GFR 60′=0.46±0.01 mL g −1 min −1*, * p<0.05) and UF (UF 30′=0.135±0.001 vs UF 60′=0.114±0.003 mL g −1 min −1*, * p<0.05). Tubular transport was not affected during the whole experimental period (120 min). On the other hand, the infusion of TsV (10 μg/mL/min) increased the basal perfusion pressure of isolated arteriolar mesenteric bed (basal pressure: 74.17±3.42 vs TsV 151.8±17.82 mmHg*, * p<0.05). TsV affects renal haemodynamics probably by a direct vasoconstrictor action leading to decreased renal flow.

The effects of a sodium and a calcium channel blocker on lethality of mice injected with the yellow scorpion (Leiurus quinquestriatus) venom

Scorpion venom toxins generally produce similar effects by mainly acting on sodium channels, and to a lesser extent, on potassium, calcium, and chloride channels. This leads to increased release of neurotransmitters and mediators, resulting in a cascade of pathological events, involving the central nervous system, the autonomic nervous system, the cardiovascular and the respiratory system, eventually leading to death. The objective of this paper was to discover whether a sodium channel blocker, lidocaine, or a calcium channel blocker, verapamil, would prolong the survival of mice injected with the venom from the common yellow scorpion Leiurus quinquestriatus quinquestriatus (LQQ). For this purpose, mice were divided into 2 groups, each injected with a different venom dose (250 or 300 µg.kg-1, s.c.). Subgroups (n=10) from each group were given venom alone; different doses of lidocaine (4, 10, 15, or 20 mg.kg-1); or several doses of verapamil (0.01, 0.03, 0.1, 0.3, or 1 mg.kg-1). All doses of lidocaine and verapamil were intravenously administered 3 minutes before, 1, 5, and 15 minutes after venom injection. Percent surviving after 24 hours was recorded in addition to the time of death. In general, lidocaine significantly prolonged survival at the dose of 10 mg.kg-1 (P<0.05 and P<0.01, versus low and high dose of venom, respectively) or 15 mg.kg-1 (P<0.01 and P<0.001, versus low and high dose of venom, respectively; Covariance Wilcoxon survival statistics), especially when injected before the venom or in the early stages of envenomation. On the other hand, in all doses administered, verapamil was either toxic or showed non-significant results. Lidocaine, the sodium channel blocker, appears to play an important role in the protection from lethality of mice injected with LQQ venom, and significantly prolonged the survival time of mice whether injected before or in the early stages of envenomation.

Improved plant protective efficacy of a baculovirus using an early promoter to drive insect-specific neurotoxin expression

Genetically improved Autographa californica (Speyer) multiple nucleopolyhedrovirus (AcMNPV), the type species of the genus Nucleopolyhedrovirus, was constructed with an insect-selective toxin gene (LqhIT2) derived from the venom of the Israeli yellow scorpion, Leiurus quinquestriatus (Ehrenberg). LqhIT2 was expressed by two distinct and temporally regulated promoters. These two promoters were the early promoter p-PCm (a pu-enhanced minimal CMV promoter) and the very late p10 promoter, resulting in recombinant viruses named vAPcmIT2 and vAP10IT2, respectively. Western blot and bioassay analysis showed that the toxin gene under the control of the early p-PCm promoter was expressed 24 h earlier than under the very late p10 promoter control, and vAPcmIT2 killed faster than vAP10IT2. The EC50 (effective concentration, EC) values of wild type AcMNPV, vAP1OIT2, and vAPcmIT2 to the 3(superscript rd)-instar larvae of Trichoplusia ni (Hubner) were 1.00, 0.19, and 0.17 polyhedral inclusion bodies (PIBs)/mm^3, respectively. Compared to the very late promoter, the early promoter could shorten the effective time (ET50) by 14~17 h. Furthermore, for the 4(superscript th)-instar larvae, compared to the wild-type virus and vAP10G, a 19~23% and 30~33% reduction in ET50 were found using vAP10IT2 and vAPcmIT2, respectively. Field trials of these two viruses showed an effective paralysis of the infected larvae which then stopped feeding, resulting in a decrease in the leaf area eaten compared to those larvae infected with wild-type virus and another control virus vAP1OG, the GFP-expression recombinant AcMNPV. Scorpion toxin driven by the early p-PCm promoter shortened the time-to-paralysis of insect larvae, and thus provided an economical pest control advantage over that driven by the very late p10 promoter.

Predatory behaviour of gekkonid lizards, Ptyodactylus spp., towards the scorpion Leiurus quinquestriatus hebraeus, and their tolerance of its venom

In the present pilot study the effect of the venom of the Israeli yellow scorpion (Leiurus quinquestriatus hebraeus (Birula, 1908)) on two Israeli fan-toed gecko lizards (Ptyodactylus guttatus von Heyden, 1827 and P. puiseuxi Boutan, 1893) was examined through (1) observations on feeding behaviour and (2) toxicity assays. It was shown that (1) the geckos ate the extremely venomous yellow scorpions in a sting-avoiding fashion and when occasionally stung they were not affected; (2) subcutaneous injections of lyophilized venom were survived by the scorpion-sympatric P. guttatus in doses of 1 mg of crude lyophilized venom per g of body weight (4000 times its ld 50 value for mice), in contrast with the presumably allopatric P. puiseuxi which died within 80 and 210 min from doses of 1 and 0.5 mg per g, respectively. The pharmacological and ecochemical aspects of the above tolerance are discussed.

Investigation of the modulation of glutamate release by sodium channels using neurotoxins

The modulation of neurotransmitter release by calcium channels is well established, yet, sodium channels were regarded mainly as charge carriers. Many lines of evidence suggest a more fine-tuning role played by sodium channels. Using rat cerebrocortical isolated nerve endings (synaptosomes) and two toxins that have separate sites of action on sodium channels and provoke distinct changes in channel kinetics, we were able to show that depending on the rate of increase in channel conductance, the outcome in terms of neurotransmitter release and calcium channel types coupled to that event are different. Mainly, our study focused on veratridine, an alkaloid from lilaceous plants that binds to sodium channel toxin site 2, and tityustoxin, a toxin purified from the venom of the Brazilian yellow scorpion Tityus serrulatus that binds to site 3. Veratridine induces a slower increase in intrasynaptosomal sodium and calcium concentrations, slower depolarization, delayed exocytosis and a slower and predominantly calcium-independent glutamate release, when compared to tityustoxin. Thus, we have used these two toxins to investigate the events that start with sodium entry and culminate with the release of glutamate in isolated nerve endings (synaptosomes) from rat cerebral cortex. With that in mind we measured intrasynaptosomal free sodium concentration [Na +] i, intrasynaptosomal free calcium concentration [Ca 2+] i, membrane potential, exocytosis and glutamate release using fluorescent probes.

The effects of lignocaine on actions of the venom from the yellow scorpion “ Leiurus quinquestriatus” in vivo and in vitro

Fatani, A.J., Harvey, A.L., Furman, B.L., and Rowan, E.G. The effects of lignocaine on actions of the venom from the yellow scorpion, Leiurus quinquestriatus, in vivo and in vitro. Toxicon, 19. Many toxins from scorpion venoms activate sodium channels, thereby enhancing neurotransmitter release. The aim of the present work was to determine if the in vivo and in vitro effects of Leiurus quinquestriatus venom ( LQQ) could be ameliorated by lignocaine, a sodium channel blocker. In urethane anaesthetised rabbits, LQQ venom (0.5 mg kg −1, i.v.) caused initial hypotension and bradycardia followed by hypertension, pulmonary oedema, electrocardiographic changes indicating conduction defects, ischaemia, infarction, and then hypotension and death. Lignocaine (1 mg kg −1 i.v. bolus initially, followed by i.v. infusion of 50 μg kg −1 min −1) significantly attenuated the majority of the venom-evoked effects and reduced mortality. Addition of LQQ venom (1, 3 and 10 μg ml −1) to chick biventer cervicis, guinea pig ileum, and rat vas deferens preparations, increased the height of electrically-induced twitches, elevated resting tension, and caused autorhythmic oscillations. Lignocaine (3 × 10 −4–1.2 × 10 −3 M) greatly attenuated these venom-evoked actions in the three preparations. Antagonists of appropriate neurotransmitters were also tested to determine the contribution of released transmitters to LQQ effects. Atropine significantly decreased the venom-elicited effects on guinea pig ileum preparations, while prazosin and guanethidine significantly reduced the venom’s actions on rat vas deferens. In chick biventer cervicis preparations, tubocurarine and hexamethonium significantly attenuated the venom-induced effects. This study supports the hypothesis that many effects of LQQ venom involve the release of neurotransmitters and may be ameliorated by treatment with lignocaine.

Second degree atrio-ventricular block and cardiotoxicity secondary to envenomation by the scorpion Leiurus quinquestriatus (‘Yellow Scorpion’) – an indication for serotherapy?

Second degree atrio-ventricular block and cardiotoxicity secondary to envenomation by the scorpion Leiurus quinquestriatus (‘Yellow Scorpion’) – an indication for serotherapy?

Effect of nifedipine ( l-type Ca channel blocker) and scorpion antivenom on rat cultured heart cells treated with venom of the yellow scorpion

Effect of nifedipine ( l-type Ca channel blocker) and scorpion antivenom on rat cultured heart cells treated with venom of the yellow scorpion

EVOLUTION OF SCORPIONISM BY Tityus bahiensis (PERTY) AND Tityus serrulatus LUTZ AND MELLO AND GEOGRAPHICAL DISTRIBUTION OF THE TWO SPECIES IN THE STATE OF SÃO PAULO - BRAZIL

Two scorpion species of medical importance occur in the state of Sao Paulo: the native brown scorpion Tityus bahiensis (Perty) and the highly toxic yellow scorpion Tityus serrulatus Lutz and Mello, which was brought into the state. The study of accident data of patients admitted to the Vital Brazil Hospital of the Butantan Institute from l982 to l993 revealed a gradual increase in stings by T. serrulatus in contrast to those by T. bahiensis with a variation from 5.2% to 29.7%. Also, an inventory of the scorpions sent to the Laboratory of Venomous Arthropods of the Butantan Institute over the same period showed an expressive growth in the number of T. serrulatus specimens in contrast to that of T. bahiensis. These data suggest a significative proliferation of T. serrulatus in the state of Sao Paulo over the past 12 years, and a probable interspecific competition between T. serrulatus and the endemic T. bahiensis. The analysis of scorpion accidents reported to the state of Sao Paulo Health Department (Secretaria de Estado da Saude de Sao Paulo) corroborated the higher severity of T. serrulatus envenoming. The results pointed to the possibility of an increase in severe envenoming and deaths by scorpion stings in the state of Sao Paulo. Aiming to contribute to scorpion prevention and control programs, the present geographical distribution of both dangerous species was mapped, pointing to the areas of higher risk of scorpionism in the state.