Taking the sting out of scorpions: Electrophysiological investigation of the relative efficacy of three antivenoms against medically significant Centruroides species.

In this study, we report the innovative application of whole-cell patch-clamp electrophysiology in assessing broad-spectrum neutralisation by three different antivenoms, of venoms from the medically significant scorpion genus Centruroides. Envenomations by as many as 21 species from the Centruroides genus result in up to 300,000 envenomations per year in Mexico, which poses significant and potentially life-threatening pathophysiology. We first evaluated the in vitro manifestation of envenomation against two human voltage-gated sodium (hNaV) channel subtypes: hNaV1.4 and hNaV1.5, which are primarily expressed in skeletal muscles and cardiomyocytes, respectively. The neutralisation of venom activity was then characterised for three different antivenoms using a direct competition model against the more potent target, hNaV1.4. While broad-spectrum neutralisation was identified, variation in neutralisation arose for Centruroides elegans, C. limpidus, C. noxius and C. suffusus venoms, despite the presence of a number of these venoms within the immunising mixture. This raises questions regarding the truly "broad" neutralisation capacity of the antivenoms. This study not only extends previous validation of the in vitro investigation of antivenom efficacy utilising the whole-cell patch-clamp technique but also underscores the potential of this animal-free model in exploring cross-reactivity, experimental scalability, and most importantly, informing clinical management practices regarding the administration of antivenom in Mexico.

Toxic Peptides from the Mexican Scorpion Centruroides villegasi: Chemical Structure and Evaluation of Recognition by Human Single-Chain Antibodies.

Alternative recombinant sources of antivenoms have been successfully generated. The application of such strategies requires the characterization of the venoms for the development of specific neutralizing molecules against the toxic components. Five toxic peptides to mammals from the Mexican scorpion Centruroides villegasi were isolated by chromatographic procedures by means of gel filtration on Sephadex G-50, followed by ion-exchange columns on carboxy-methyl-cellulose (CMC) resins and finally purified by high-performance chromatography (HPLC) columns. Their primary structures were determined by Edman degradation. They contain 66 amino acids and are maintained well packed by four disulfide bridges, with molecular mass from 7511.3 to 7750.1 Da. They are all relatively toxic and deadly to mice and show high sequence identity with known peptides that are specific modifiers of the gating mechanisms of Na+ ion channels of type beta-toxin (ß-ScTx). They were named Cv1 to Cv5 and used to test their recognition by single-chain variable fragments (scFv) of antibodies, using surface plasmon resonance. Three different scFvs generated in our laboratory (10FG2, HV, LR) were tested for recognizing the various new peptides described here, paving the way for the development of a novel type of scorpion antivenom.

Scorpion-Induced Acute Coronary Syndrome: A Stinging Complication.

The Tityus trinitatis, a black scorpion species endemic to the fauna of Trinidad, has been implicated in envenomation with devastating clinical sequelae such as acute pancreatitis and major adverse cardiovascular events. We present the first in-Caribbean case of a 59-year-old Caribbean South Asian male with human immunodeficiency virus who presented with a non-ST-segment-elevation acute coronary syndrome after being stung, which was managed with comprehensive, guideline-directed medical therapy. The clinician should be cognizant of scorpion-induced acute coronary syndrome (ACS) as a potential sequela of envenomation and its clinical management.

Urbanization and scorpion stings in Manaus, the largest metropolis in the Brazilian Amazon.

This study analyzed a total of 260 confirmed scorpion stings reported in the city of Manaus, in the Brazilian Amazon, from 1990 to 2020. Cases were mapped according to the GPS location of their occurrence and plotted on a satellite image of the city. The stings generally occurred close to green areas, and the hotspots of stings moved north as city grew into that direction over time. Spatial analysis shows that scorpion stings mostly occur in poor, recently urbanized areas. The rapid and unplanned urbanization of originally forested areas, without offering adequate infrastructure and services, creates favorable conditions for infestation by scorpions and increases the risk of scorpion stings.

Unveiling Tst3, a Multi-Target Gating Modifier Scorpion α Toxin from Tityus stigmurus Venom of Northeast Brazil: Evaluation and Comparison with Well-Studied Ts3 Toxin of Tityus serrulatus.

Studies on the interaction sites of peptide toxins and ion channels typically involve site-directed mutations in toxins. However, natural mutant toxins exist among them, offering insights into how the evolutionary process has conserved crucial sequences for activities and molecular target selection. In this study, we present a comparative investigation using electrophysiological approaches and computational analysis between two alpha toxins from evolutionarily close scorpion species of the genus Tityus, namely, Tst3 and Ts3 from T. stigmurus and T. serrulatus, respectively. These toxins exhibit three natural substitutions near the C-terminal region, which is directly involved in the interaction between alpha toxins and Nav channels. Additionally, we characterized the activity of the Tst3 toxin on Nav1.1-Nav1.7 channels. The three natural changes between the toxins did not alter sensitivity to Nav1.4, maintaining similar intensities regarding their ability to alter opening probabilities, delay fast inactivation, and induce persistent currents. Computational analysis demonstrated a preference for the down conformation of VSD4 and a shift in the conformational equilibrium towards this state. This illustrates that the sequence of these toxins retained the necessary information, even with alterations in the interaction site region. Through electrophysiological and computational analyses, screening of the Tst3 toxin on sodium isoform revealed its classification as a classic α-NaTx with a broad spectrum of activity. It effectively delays fast inactivation across all tested isoforms. Structural analysis of molecular energetics at the interface of the VSD4-Tst3 complex further confirmed this effect.

Does Covid-19 influence the dynamics of envenomation by animals in a country strongly affected by both conditions? Epidemiological data from Brazil.

The impact of Covid-19 on envenomations by venomous animals in countries heavily affected by both conditions has not been quantified yet. Brazil shows high incidence of envenomations by scorpions, spiders and snakes and was heavily affected by waves of Covid-19. To determine how the pandemic impacted the epidemiology of envenomations by those three groups of venomous animals, we used online databases from two surveillance sources on number of cases and mortality. During the years before and during the pandemic, scorpion stings typically occurred in adults of both sexes in urban zones in the Southeast and Northeast regions. Spider bites occurred mainly in the South region, in adults of both sexes in urban zone. Snakebites affected mainly rural adult men in the Amazon. Between 2007 and 2021, overall incidence of cases by scorpions, spiders and snakes decreased after the beginning of the pandemic, snakebites did not show changes after the pandemic started in Brazil, but cases by scorpions and spiders decreased. No changes in the incidence of deaths were observed. On national level, Covid-19 affected some demographic, clinical and epidemiological aspects in cases by scorpions, spiders and snakes.

Use of point-of-care ultrasound to assess the severity of scorpion stings in hospitalized patients.

INTRODUCTION: Scorpionism is a public health problem, especially in tropical regions. In Brazil, the prevalence of envenomation by scorpions is high, and the average national lethality is around 0.16 percent. The Tityus serrulatus scorpion is the primary species of medical importance. However, objective tools to predict and define the severity of these envenomations are lacking. MATERIALS AND METHODS: This was an observational study conducted among patients aged 0-19 years with scorpionism. Patients were admitted to a reference hospital between December 2020 and May 2022. Point-of-care ultrasound was performed within 24 hours of the scorpion sting. RESULTS: Forty-nine patients were included, with a median age of 3.6 (interquartile range 2.3-5.3) years and a predominance of females (51 percent). Fifteen patients (30.6 percent) presented major life-threatening signs, 32 (65.3 percent) minor systemic manifestations, and two (4.1 percent) only local manifestations. Left ventricular dysfunction was identified in 13 patients (26.5 percent). Ten patients (20.4 percent) presented pattern B (visualization of three or more B lines in the evaluated quadrant) in at least one lung window. The sensitivity and specificity of cardiac and pulmonary ultrasound to identify the most severely ill patients were 86 percent and 94 percent, respectively. DISCUSSION: The changes found on point-of-care ultrasound were associated with life-threatening signs. All patients with class III envenomation were referred to the intensive care unit, showing the importance of early identification of this subgroup. The main limitations were the small sample size and the fact that admission to intensive care was not based on systematic criteria. CONCLUSIONS: Point-of-care ultrasound is able to identify early signs of pulmonary congestion and heart failure in scorpionism. It can be useful for the objective selection of patients who are at a higher risk of complications and death and who require intensive support; it may also be valuable for periodic reassessments. Point-of-care ultrasound is a valuable tool for identifying and monitoring severe cases of scorpionism.

Epidemiological profile of accidents involving venomous animals in Maranhão from 2012 to 2021 / Perfil epidemiológico de acidentes envolvendo animais peçonhentos no Maranhão no período de 2012 a 2021 / Perfil epidemiológico de los accidentes con animales venenosos en Maranhão de 2012 a 2021

Background and Objectives: the second greatest cause of human poisoning in Brazil is caused by venomous animals. Thus, this study aimed to analyze clinical and sociodemographic data, in order to outline the epidemiological profile of accidents involving venomous animals in Maranhão. Methods: this is an ecological study with a quantitative approach, carried out from data collection by the Notifiable Diseases Information System (SINAN) of notifications of accidents by venomous animals that occurred in the state of Maranhão from 2012 to 2021. Results: of the 34,808 cases reported, it was found that the highest incidence occurred in 2019 and, in general, January is the month in which most accidents are recorded. When analyzing the sociodemographic profile, it is noted that the majority of victims are represented by male individuals, between 20-39 years old, with an unidentified level of education. In the case of clinical and epidemiological criteria, it was evident that snakes of the genus Bothrops are responsible for the highest incidence, with most cases involving venomous animals occurring within 1-3 hours after the bite. Among the cases identified, 63% were described as mild and 82% progressed to cure. Conclusion: the epidemiological profile described in the study can be used by health agents to plan preventive measures in Primary Health Care, and knowing the profile of victims is essential to prevent and promote quality care.(AU)

Justificativa e Objetivos: a segunda maior causa de envenenamento humano no Brasil é ocasionada por animais peçonhentos. Dessa forma, este estudo visou analisar dados clínicos e sociodemográficos, a fim de traçar o perfil epidemiológico dos acidentes envolvendo animais peçonhentos no Maranhão. Métodos: trata-se de estudo ecológico de abordagem quantitativa, realizado a partir da coleta de dados pelo Sistema de Informações de Agravos de Notificação (SINAN) de acidentes por animais peçonhentos ocorridos no estado do Maranhão no período de 2012 a 2021. Resultados: dos 34.808 casos notificados, constatou-se que a maior incidência ocorreu no ano de 2019 e, em geral, janeiro é o mês em que mais se registram acidentes. Ao analisar o perfil sociodemográfico, nota-se que a maior parte das vítimas é representada por indivíduos do sexo masculino, entre 20 e 39 anos, com grau de escolaridade não identificado. Tratando-se de critérios clínicos e epidemiológicos, evidenciou-se que as serpentes do gênero Bothrops são as responsáveis pela maior incidência, sendo que a maior parte dos atendimentos envolvendo animais peçonhentos ocorreu no intervalo de 1-3 horas após a picada. Entre os casos identificados, 63% foram descritos como leve e 82% evoluíram para a cura. Conclusão: o perfil epidemiológico descrito no estudo pode ser utilizado por agentes de saúde para o planejamento de medidas preventivas na Atenção Primária à Saúde, e conhecer o perfil das vítimas é essencial para prevenir e promover uma assistência de qualidade.(AU)

Justificación y Objetivos: la segunda causa de envenenamiento humano en Brasil es causada por animales venenosos. Así, este estudio tuvo como objetivo analizar datos clínicos y sociodemográficos, con el fin de delinear el perfil epidemiológico de los accidentes con animales venenosos en Maranhão. Métodos: se trata de un estudio ecológico con abordaje cuantitativo, realizado a partir de la recolección de datos por el Sistema de Información de Enfermedades de Declaración Obligatoria (SINAN) de relatos de accidentes por animales ponzoñosos ocurridos en el estado de Maranhão entre 2012 y 2021. Resultados: de los 34.808 casos reportados, se encontró que la mayor incidencia ocurrió en 2019 y, en general, enero es el mes en el que se registran más accidentes. Al analizar el perfil sociodemográfico, se observa que la mayoría de las víctimas están representadas por personas del sexo masculino, entre 20-39 años, y con nivel de escolaridad no identificado. En el caso de los criterios clínicos y epidemiológicos, se evidenció que las serpientes del género Bothrops son las responsables de la mayor incidencia, y la mayoría de los casos que involucran animales venenosos ocurren entre 1 y 3 horas después de la mordedura. Entre los casos identificados, el 63% fueron descritos como leves y el 82% progresó hacia la curación. Conclusión: el perfil epidemiológico descrito en el estudio puede ser utilizado por los agentes de salud para planificar medidas preventivas en la atención básica de salud, y conocer el perfil de las víctimas es fundamental para prevenir y promover una atención de calidad.(AU)

First biochemical and behavioural analysis of the response of the scorpion Urophonius brachycentrus (Thorell: 1876) upon exposure to an organophosphate.

Scorpionism is an increasing public health problem in the world. Although no specific methodology or product is currently available for the control of those arachnids, the use of insecticides could be an effective tool. Chlorpyrifos is one of the insecticides used, but to date, whether scorpions recognise surfaces with that insecticide and how it affects their physiology and/or biochemistry is unknown. In the present study, we observed that scorpions recognise surfaces with 0.51 and 8.59 µg/cm2 of chlorpyrifos and avoid those areas. The 0.51 µg/cm2 concentration produced a decrease in acetylcholinesterase and an increase in catalase, superoxide dismutase and glutathione S-transferase, whereas the 8.59 µg/cm2 concentration evoked a decrease in acetylcholinesterase and an increase in catalase and glutathione S-transferase. Using the comet assay, we observed that the insecticide at 0.17, 0.51 and 8.59 µg/cm2 caused DNA damage. Finally, we found that the insecticide does not generate significant variations in glutathione peroxidase, glutathione reductase, the amount of protein or lipid peroxidation. The present results offer a comprehensive understanding of how scorpions respond, both at the biochemical and behavioural levels, when exposed to insecticides.

Characterization of Sodium Channel Peptides Obtained from the Venom of the Scorpion Centruroides bonito.

Five peptides were isolated from the venom of the Mexican scorpion Centruroides bonito by chromatographic procedures (molecular weight sieving, ion exchange columns, and HPLC) and were denoted Cbo1 to Cbo5. The first four peptides contain 66 amino acid residues and the last one contains 65 amino acids, stabilized by four disulfide bonds, with a molecular weight spanning from about 7.5 to 7.8 kDa. Four of them are toxic to mice, and their function on human Na+ channels expressed in HEK and CHO cells was verified. One of them (Cbo5) did not show any physiological effects. The ones toxic to mice showed that they are modifiers of the gating mechanism of the channels and belong to the beta type scorpion toxin (ß-ScTx), affecting mainly the Nav1.6 channels. A phylogenetic tree analysis of their sequences confirmed the high degree of amino acid similarities with other known bona fide ß-ScTx. The envenomation caused by this venom in mice is treated by using commercially horse antivenom available in Mexico. The potential neutralization of the toxic components was evaluated by means of surface plasmon resonance using four antibody fragments (10FG2, HV, LR, and 11F) which have been developed by our group. These antitoxins are antibody fragments of single-chain antibody type, expressed in E. coli and capable of recognizing Cbo1 to Cbo4 toxins to various degrees.

Scorpion envenomation in Brazil and its relationship with the social determinants of health: A population-based ecological study.

This study comprehensively analyzed cases of scorpion envenomation in Brazil, exploring the temporal trends and geographic patterns of such incidents between January 1, 2012, and December 31, 2022. Simultaneously, we assessed the correlation between scorpion envenomation and social determinants of health and social vulnerability. We conducted a population-based ecological study, gathering information on the number of scorpion envenomation cases in Brazil, as well as socioeconomic data and social vulnerability indicators across the 5,570 Brazilian municipalities. The season-trend model, based on the classical additive decomposition method, informed estimations of scorpion envenomation variations over time. The spatial correlation of scorpion envenomation with socioeconomic and vulnerability indicators was assessed using the Bivariate Moran's I. A total of 1,343,224 cases of scorpion envenomation were recorded in Brazil from Jan 2012 to Dec 2022. A single increasing time trend was observed for the entire country for this period (APC 8.94, P < 0.001). The seasonal analysis was significant for Brazil as a whole and all regions (p < 0.001), with peaks evident between October and November. The spatial distribution of cases was heterogeneous, with spatial clusters concentrated in the high-risk Southeast and Northeast regions. There was a high incidence of scorpion envenomation in municipalities facing social vulnerability, and, paradoxically, in those with better sanitation and waste collection. Our study revealed a heterogeneous geographical distribution of scorpion accidents in Brazil. Municipalities with higher social vulnerability exhibited a high incidence of scorpion envenomation.

An overview of some enzymes from buthid scorpion venoms from Colombia: Centruroides margaritatus, Tityus pachyurus, and Tityus n. sp. aff. metuendus.

Background: In Colombia, several species of Buthidae scorpions belonging to the genera Centruroides and Tityus coexist, and their stings are considered life-threatening to humans because of their venom neurotoxins. Despite previous studies focusing on neurotoxins from these scorpion genera, little is known about the enzymes present in their venoms and their relationship with whole venom toxicity. Methods: Here, using proteomic and biochemical protocols the enzymatic activities of the venoms of three Colombian scorpion species, C. margaritatus, T. pachyurus, and T. n. sp. aff. metuendus, were compared to establish the presence and absence of enzymes such as phospholipases, hyaluronidases, and proteases that could be related to venom toxicity. Results: C. margaritatus was positive for hyaluronidases, T. n. sp. aff. metuendus for proteases, and T. pachyurus exhibited activity for all three mentioned enzymes. Conclusion: This information provides valuable insights into the specific enzyme diversity of each species' venom and their potential role in venom toxicity, which could contribute to the development of better treatments and prevention strategies for scorpion envenomation.

Divergence in toxin antigenicity and venom enzymes in Tityus melici, a medically important scorpion, despite transcriptomic and phylogenetic affinities with problematic Brazilian species.

The Brazilian scorpion Tityus melici, native to Minas Gerais and Bahia, is morphologically related to Tityus serrulatus, the most medically significant species in Brazil. Despite inhabiting scorpion-envenomation endemic regions, T. melici venom remains unexplored. This work evaluates T. melici venom composition and function using transcriptomics, enzymatic activities, and in vivo and in vitro immunological analyses. Next-Generation Sequencing unveiled 86 components putatively involved in venom toxicity: 39 toxins, 28 metalloproteases, seven disulfide isomerases, six hyaluronidases, three phospholipases and three amidating enzymes. T. serrulatus showed the highest number of toxin matches with 80-100 % sequence similarity. T. melici is of medical importance as it has a venom LD50 of 0.85 mg/kg in mice. We demonstrated venom phospholipase A2 activity, and elevated hyaluronidase and metalloprotease activities compared to T. serrulatus, paralleling our transcriptomic findings. Comparison of transcriptional levels for T. serrulatus and T. melici venom metalloenzymes suggests species-specific expression patterns in Tityus. Despite close phylogenetic association with T. serrulatus inferred from COI sequences and toxin similarities, partial neutralization of T. melici venom toxicity was achieved when using the anti-T. serrulatus antivenom, implying antigenic divergence among their toxins. We suggest that the Brazilian therapeutic scorpion antivenom could be improved to effectively neutralize T. melici venom.

Antimicrobial, toxicological, and antigenic characteristics of three scorpion venoms from Colombia: Centruroides margaritatus, Tityus pachyurus and Tityus n. sp. aff. metuendus.

The venom fractions of three buthid scorpion species from Colombia, C. margaritatus, T. pachyurus and T. n. sp. aff. metuendus, were examined for antimicrobial and toxicity toward mice and insects. The three venoms were separated into individual fractions using RP-HPLC, resulting in 85 fractions from C. margaritatus, 106 from T. pachyurus, and 70 from T. n. sp. aff. metuendus. The major fractions from the three scorpion venoms, which were eluted between 35 and 50 min, were tested for antimicrobial activity and toxicity. It was confirmed that the venom of the three species contains fractions with antimicrobial peptides that were evaluated against two bacterial strains of public health importance, Pseudomonas aeruginosa and Staphylococcus aureus. The venom of C. margaritatus had two antimicrobial fractions that showed activity against the named tested strains. The venom of T. pachyurus had three fractions that showed activity against S. aureus and two against both bacterial strains. Finally, the venom of T. n. sp. aff. metuendus had one fraction that showed activity against S. aureus, and five fractions showed activity against both bacterial strains. Also, some peptide fractions from the three venoms were toxic to mice. Last, the venoms of C. margaritatus and T. pachyurus were used as immunogens to obtain neutralizing antibodies against its respective venoms and to observe antibody recognition to related and unrelated scorpion venoms. A total of 15 mg of lyophilized antibodies were able to neutralize 1.5⋅LD50 of the venoms from T. n. sp. aff. metuendus, T. pachyurus and C. margaritatus, respectively. This information provides valuable insights into the diversity of each species' venom and their potential role in antimicrobial and venom toxicity.

Scorpion sting envenomation outbreak in Mexico. Strategies for prevention and control.

In Mexico occurs 25% of all worldwide cases of scorpion sting envenomation (SSE). An outbreak of SSE was identified in Villa Unión, Sinaloa, Mexico. The objective of this study is to describe the outbreak, and prevention and control strategies implemented. The design was a cross-sectional study. Eligibility criteria included confirmed cases (n = 425) identified from the date the outbreak was recognized (from November 08, 2023 to July 10, 2023). The cases from Villa Unión (n = 231) were included for the analysis of epidemiological and clinical findings. The research followed the recommendations of the Initiative Reporting of studies Conducted Using Observational Routinely collected Data (RECORD). Of the total cases (n = 425), 398 (93.6%) were from the municipality of Mazatlán, and 231 (58%) were from Villa Unión. The incidence rate was 13.64 per 1000 persons. The average cases per week was 51.5(SD ± 12). The male-to-female ratio was 3:4, the average age was 30.7(SD ± 19) years. Most of cases occurred in the 25-44 age group. The sting occurred mostly inside houses (n = 200, 86.5%). The predominant symptoms were local pain (95.2%), and local paresthesia (75.8%). The Case fatality rate was 0%. Implementation of prevention and control strategies based on field epidemiological research and scientific evidence are necessary to reduce the incidence and prevent fatal complications.

Extraction and quantification of antivenomous antibodies in chicken eggs against scorpion venom / Extração e quantificação de anticorpos entivenenos em ovos de galinha contra veneno de escorpião

Avian-derived IgY is thought to be the best therapy for scorpion bites concerning low-level side effects. The present study analyzed a hypothesis about the neutralization of scorpion venom Androcotonus australis through antibodies produced in the egg yolks of chickens. The venom used for inoculation was obtained from Androctonus australis (yellow fat-tailed scorpion) from southern Punjab, Pakistan. The lethal dose of LD50 against scorpion venom was calculated in chickens and mice. Safe doses were given to egg-laying chickens to produce IgY antibodies. The antivenom IgY antibodies were extracted from the egg yolks of immunized chicken using the polyethylene glycol (PEG) method. Moreover, IgY was confirmed through sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and the Ouchterlony double immunodiffusion assay test. The antibody titers were evaluated by the enzyme-linked immunosorbent assay (ELISA). The neutralisation capacity of extracted anti-scorpion antibodies was tested on mice. The calculated LD50 of scorpion venom for chicken and mice was 4 mg/kg and 2.5 mg/kg, respectively. SDS-PAGE and Ouchterlony double immunodiffusion confirmed the presence of IgY against scorpion venom. The maximum titer value of specific IgY produced against scorpion venom was 3.5 ug/ml. A concentration of 220 ul/LD50 was effective to neutralize 1 mg of scorpion venom. It is suggested that IgY obtained from egg yolks is safe against targeted venom and can be used as an effective alternative to equine IgG antibodies against scorpion envenoming.

Acredita-se que a IgY derivada de aves seja a melhor terapia para picadas de escorpião em relação aos efeitos colaterais. O presente estudo teve como objetivo analisar uma hipótese sobre a neutralização do veneno do escorpião Androcotonus australis através de anticorpos produzidos na gema de ovos de galinhas. O veneno usado para inoculação foi obtido de Androctonus australis (escorpião amarelo de cauda gorda) do sul de Punjab, Paquistão. A dose letal de LD50 contra veneno de escorpião foi calculada em galinhas e camundongos. Doses seguras foram dadas a galinhas poedeiras para produzir anticorpos IgY. Os anticorpos antiveneno IgY foram extraídos das gemas de ovos de galinhas imunizadas pelo método do polietilenoglicol (PEG). Além disso, a IgY foi confirmada por eletroforese em gel de poliacrilamida e dodecil sulfato de sódio (SDS-PAGE) e pelo teste de imunodifusão dupla de Ouchterlony. Os títulos de anticorpos foram avaliados pelo ensaio imunoenzimático (ELISA). A capacidade de neutralização dos anticorpos anti-escorpião extraídos foi testada em camundongos. A LD50 calculada do veneno de escorpião para galinhas e camundongos foi de 4 mg/kg e 2,5 mg/kg, respectivamente. SDS-PAGE e imunodifusão dupla Ouchterlony confirmaram a presença de IgY contra veneno de escorpião. O valor máximo do título de IgY específico produzido contra veneno de escorpião foi de 3,5 ug/ml. Uma concentração de 220 ul/LD50 foi considerada eficaz para neutralizar 1 mg de veneno de escorpião. Sugere-se que a IgY obtida da gema do ovo seja segura contra o veneno direcionado e possa ser usada como uma alternativa eficaz aos anticorpos IgG equinos contra o envenenamento por escorpiões.

An overview of some enzymes from buthid scorpion venoms from Colombia: Centruroides margaritatus, Tityus pachyurus, and Tityus n. sp. aff. metuendus

Background: In Colombia, several species of Buthidae scorpions belonging to the genera Centruroides and Tityus coexist, and their stings are considered life-threatening to humans because of their venom neurotoxins. Despite previous studies focusing on neurotoxins from these scorpion genera, little is known about the enzymes present in their venoms and their relationship with whole venom toxicity. Methods: Here, using proteomic and biochemical protocols the enzymatic activities of the venoms of three Colombian scorpion species, C. margaritatus, T. pachyurus, and T. n. sp. aff. metuendus, were compared to establish the presence and absence of enzymes such as phospholipases, hyaluronidases, and proteases that could be related to venom toxicity. Results: C. margaritatus was positive for hyaluronidases, T. n. sp. aff. metuendus for proteases, and T. pachyurus exhibited activity for all three mentioned enzymes. Conclusion: This information provides valuable insights into the specific enzyme diversity of each species' venom and their potential role in venom toxicity, which could contribute to the development of better treatments and prevention strategies for scorpion envenomation.

On one of the smallest Amazonian scorpions: a new species of Microtityus (Scorpiones, Buthidae) from Brazil, with amended diagnosis and potential distribution analysis for the genus

A new scorpion species, Microtityus adriki n. sp., is described based on adult specimens collected in Cantá, state of Roraima (RR), northern Brazil. Microtityus adriki n. sp. is the second species of Microtityus Kjellesvig-Waering, 1966 known from Brazil and is one of the smallest scorpion species (12.39-19.47 mm) in the Amazonian region. In this study, we propose an amended generic diagnosis and a specific diagnosis, describe the male hemispermatophore of Microtityus, give the sequence of COI barcode, and present a potential distribution analysis for the genus. The morphology of the male hemispermatophore of Microtityus differs from that of other Neotropical buthid genera, except for the number of lobes (three lobes), which is a character state shared with several genera. The potential distribution model generated by MaxEnt suggests high environmental suitability for the genus in the Antilles and northern South America, with scattered high suitability in several regions of Central America. However, the model did not indicate high suitability in areas where Brazilian species occur (i.e., Microtityus adriki n. sp. and Microtityus vanzolinii Lourenço & Eickstedt, 1983), and this could be explained by a sampling bias. Therefore, future studies, including extensive sampling, are required to better understand the biogeographic processes behind the distribution of this genus.

Exploring species diversity and abundance of scorpions (Arachnida: Scorpiones) in certain regions of Khyber Pakhtunkhwa, Pakistan / Explorando a diversidade de espécies e abundância de escorpiões (Arachnida: Scorpiones) em certas regiões de Khyber Pakhtunkhwa, Paquistão

Despite scorpion diversity has long been acknowledged, the mystery of how it develops remains unresolved. The geographical distribution, species abundance and biodiversity of scorpions fauna in Khyber Pakhtunkhwa is poorly explored with many aspects like morphological, geographical, ecological and phylogenetically. As a result of faunaistic study on scorpions a total of 171 specimens from various regimes, Charsadda, Mardan, Peshawar and Kohat districts of Khyber Pakhtunkhwa, Pakistan from March 2018 to October 2018 were collected. GarminTM GPS V Plus device. The software Arc GIS 10.2 was used to create maps of the study areas. Pitfall traps were used to gather samples from sandy habitats and pastureland. Five species Hottentotta tamulus Fabricius, 1798, with (35%), Scorpiops pseudomontanus Kovarik and Ahmed, 2009, (26%), Orthochirus fuscipes Pocock, 1900, (15%), Hottentotta buchariensis Birula, 1897, (13%) and Deccanometrus latimanus Pocock, 1894, (11%) were detected in our proposed study. The research indicates that abundance and temperature have a favorable connection, while abundance and humidity get a negative correlation. The value of evenness shows the strong equilibrium between the effectiveness of sampling species, and the Shannon's index suggests that the Pakistani region has a high level of scorpion variety.

Apesar de a diversidade de escorpiões ser reconhecida há muito tempo, permanece sem solução o mistério de como eles se desenvolvem. A distribuição geográfica, a abundância de espécies e a biodiversidade da fauna de escorpiões em Khyber Pakhtunkhwa são pouco exploradas quanto a aspectos morfológicos, geográficos, ecológicos e filogenéticos. Como resultado do estudo faunístico em escorpiões, foi coletado um total de 171 espécimes de vários regimes nos distritos de Charsadda, Mardan, Peshawar e Kohat, de Khyber Pakhtunkhwa, Paquistão, de março de 2018 a outubro de 2018. Dispositivo GarminTM GPS V Plus. O software Arc GIS 10.2 foi utilizado para criar mapas das áreas de estudo. Armadilhas de queda foram usadas para coletar amostras de habitats arenosos e pastagens. Cinco espécies Hottentotta tamulus Fabricius, 1798 (35%), Scorpiops pseudomontanus Kovarik and Ahmed, 2009 (26%), Orthochirus fuscipes Pocock, 1900 (15%), Hottentotta buchariensis Birula, 1897 (13%) e Deccanometrus latimanus Pocock, 1894 (11%) foram detectados em nosso estudo proposto. A pesquisa indica que abundância e temperatura têm uma relação favorável, enquanto abundância e umidade têm uma correlação negativa. O valor da uniformidade mostra o forte equilíbrio na eficácia da amostragem de espécies, e o índice de Shannon sugere que a região paquistanesa tem um alto nível de variedade de escorpiões.

Heteroctenus junceus Scorpion Venom Modulates the Concentration of Pro-Inflammatory Cytokines in F3II Tumor Cells.

The ability of Heteroctenus junceus scorpion venom to modulate the concentration of cytokines related to its antitumoral effect is unknown. F3II cells were treated with » IC50, ½ IC50 and the IC50 of H. junceus scorpion venom. Tumor growth kinetics in F3II-bearing mice were evaluated after 24 days of oral administration of venom doses. The effect of tumor lysates on F3II cell viability was evaluated by MTT assay, while cytokines present in each sample were determined by ELISA. In supernatant, H. junceus scorpion venom decreased the concentration of IL-6 (p < 0.001), IFN-γ (p < 0.001), IL-1ß (p < 0.01); meanwhile IL-12 (p < 0.001) and TNF-α (p < 0.001) levels increased significantly, according to the concentration and the time of incubation. Heteroctenus junceus scorpion venom effectively inhibits in vivo tumor progression. In the sera, a significant decrease was observed in TNF-α levels (p < 0.05). In tumor lysates, IL-6 decreased significantly in the groups treated with 12.5 mg/kg (p < 0.001) and 25 mg/kg (p < 0.05). Heteroctenus junceus scorpion venom is capable of modulating other proinflammatory and protumoral cytokines involved in the inflammation associated with cancer.