High chromosome variability and the presence of multivalent associations in buthid scorpions.

In this study, we investigated the mitotic and meiotic chromosomes of 11 Buthidae scorpion species, belonging to three genera (Ananteris, Rhopalurus and Tityus), to obtain detailed knowledge regarding the mechanisms underlying the intraspecific and/or interspecific diversity of chromosome number and the origin of the complex chromosome associations observed during meiosis. The chromosomes of all species did not exhibit a localised centromere region and presented synaptic and achiasmatic behaviour during meiosis I. Spermatogonial and/or oogonial metaphase cells of these buthids showed diploid numbers range from 2n = 6 to 2n = 28. In most species, multivalent chromosome associations were observed in pachytene and postpachytene nuclei. Moreover, intraspecific variability associated with the presence or absence of chromosome chains and the number of chromosomes in the complex meiotic configurations was observed in some species of these three genera. Silver-impregnated cells revealed that the number and location of nucleolar organiser regions (NORs) remained unchanged despite extensive chromosome variation; notably, two NORs located on the terminal or subterminal chromosome regions were commonly observed for all species. C-banded and fluorochrome-stained cells showed that species with conspicuous blocks of heterochromatin exhibited the lowest rate of chromosomal rearrangement. Based on the investigation of mitotic and meiotic cells, we determined that the intraspecific variability occurred as a consequence of fission/fusion-type chromosomal rearrangements in Ananteris and Tityus species and reciprocal translocation in Rhopalurus species. Furthermore, we verified that individuals presenting the same diploid number differ in structural chromosome organisation, giving rise to intraspecific differences of chromosome association in meiotic cells (bivalent-like elements or chromosome chains).

Spatiotemporal bayesian modelling of scorpionism and its risk factors in the state of São Paulo, Brazil.

BACKGROUND: Scorpion stings in Brazil represent a major public health problem due to their incidence and their potential ability to lead to severe and often fatal clinical outcomes. A better understanding of scorpionism determinants is essential for a precise comprehension of accident dynamics and to guide public policy. Our study is the first to model the spatio-temporal variability of scorpionism across municipalities in São Paulo (SP) and to investigate its relationship with demographic, socioeconomic, environmental, and climatic variables. METHODOLOGY: This ecological study analyzed secondary data on scorpion envenomation in SP from 2008 to 2021, using the Integrated Nested Laplace Approximation (INLA) to perform Bayesian inference for detection of areas and periods with the most suitable conditions for scorpionism. PRINCIPAL FINDINGS: From the spring of 2008 to 2021, the relative risk (RR) increased eight times in SP, from 0.47 (95%CI 0.43-0.51) to 3.57 (95%CI 3.36-3.78), although there has been an apparent stabilization since 2019. The western, northern, and northwestern parts of SP showed higher risks; overall, there was a 13% decrease in scorpionism during winters. Among the covariates considered, an increase of one standard deviation in the Gini index, which captures income inequality, was associated with a 11% increase in scorpion envenomation. Maximum temperatures were also associated with scorpionism, with risks doubling for temperatures above 36°C. Relative humidity displayed a nonlinear association, with a 50% increase in risk for 30-32% humidity and reached a minimum of 0.63 RR for 75-76% humidity. CONCLUSIONS: Higher temperatures, lower humidity, and social inequalities were associated with a higher risk of scorpionism in SP municipalities. By capturing local and temporal relationships across space and time, authorities can design more effective strategies that adhere to local and temporal considerations.

First report of an accident caused by Jaguajir agamemnon (C.L. Koch, 1839) (Scorpiones, Buthidae) in Paraná state, Brazil.

We report the first pediatric case of a Jaguajir agamemnon scorpion sting. This case occurred in the state of Paraná and is the first record of this species in southern Brazil. The patient was admitted within 15 min, with pain, local edema, erythema, whole-body pruritus, and tongue paresthesia within the first two hours, which disappeared thereafter. The patient's condition was considered mild, with a positive outcome, and she recovered completely.

Detection of areas vulnerable to scorpionism and its association with environmental factors in São Paulo, Brazil.

Accidents caused by scorpions are considered a neglected condition and represent a major health problem in most tropical countries, especially for children and elderly people. In Brazil, scorpionism is recurrent in the southeast region, mainly in the state of São Paulo, due to the progressive increase in scorpions found in urban habitats. Thus, our study aimed to provide better insights into the geographic and epidemiological characteristics of scorpion envenomation in São Paulo state and identify the environmental factors that are associated with these accidents. This is an ecological and retrospective study with secondary data on scorpion accidents in the state of São Paulo from 2008 to 2018 obtained from the Notifiable Disease Information System. The SatScan software was used to identify the higher- and lower-risk spatiotemporal clusters. A total of 145,464 scorpion sting cases were recorded in the state of São Paulo, between 2008 and 2018; there was a four-fold increase in the incidence rate. Accidents occurred more frequently in the spring season, wherein higher-risk clusters were in the north and northwest regions of the state. High temperatures, low precipitation, and poor natural vegetation are associated with higher risk areas. Our study mapped vulnerable areas for scorpion accidents that can aid in the design of efficient public health policies, which should be intensified during the spring season.

Scorpion envenomation in the state of São Paulo, Brazil: Spatiotemporal analysis of a growing public health concern.

Scorpion envenomation is a significant public health concern in São Paulo, Brazil, and its incidence and mortality have increased in recent decades. The present study analyzed documented scorpion envenomation notifications from 2008 to 2018 throughout the 645 municipalities of São Paulo. Annual incidence and mortality rates were calculated and stratified according to sex and age. The local empirical Bayesian method and Getis-Ord Gi* statistic were used to represent standardized incidence rates in the municipalities and to identify high- and low-risk agglomerates. The incidence rate of scorpion envenomation quintupled between 2008 and 2018. Overall, the risk was higher for man, and increased with age. Deaths due to envenomation, however, were concentrated almost entirely in children 0-9 years of age. Incidence maps showed that the risk of envenomation increased in almost all regions and municipalities of São Paulo throughout the study period. The highest incidence rates were found in the western, northwestern and northern regions of the state, in contrast to the São Paulo metropolitan area and southern and coastal regions. Hot spots were identified in the Presidente Prudente, Barretos, São José do Rio Preto, and Araçatuba regional health districts, which over time formed a single high-risk cluster. In spatial terms, however, deaths were randomly distributed. In this study, we identified areas and populations at risk of scorpion envenomation and associated-fatalities, which can be used to support decision-making by health services to reduce human contact with these arachnids and avoid fatalities, especially in children.

Complex meiotic configuration of the holocentric chromosomes: the intriguing case of the scorpion Tityus bahiensis.

Mitotic and meiotic chromosomes of Tityus bahiensis were investigated using light (LM) and transmission electron microscopy (TEM) to determine the chromosomal characteristics and disclose the mechanisms responsible for intraspecific variability in chromosome number and for the presence of complex chromosome association during meiosis. This species is endemic to Brazilian fauna and belongs to the family Buthidae, which is considered phylogenetically basal within the order Scorpiones. In the sample examined, four sympatric and distinct diploid numbers were observed: 2n = 5, 2n = 6, 2n = 9, and 2 = 10. The origin of this remarkable chromosome variability was attributed to chromosome fissions and/or fusions, considering that the decrease in chromosome number was concomitant with the increase in chromosome size and vice versa. The LM and TEM analyses showed the presence of chromosomes without localised centromere, the lack of chiasmata and recombination nodules in male meiosis, and two nucleolar organiser regions carrier chromosomes. Furthermore, male prophase I cells revealed multivalent chromosome associations and/or unsynapsed or distinctly associated chromosome regions (gaps, less-condensed chromatin, or loop-like structure) that were continuous with synapsed chromosome segments. All these data permitted us to suggest that the chromosomal rearrangements of T. bahiensis occurred in a heterozygous state. A combination of various factors, such as correct disjunction and balanced segregation of the chromosomes involved in complex meiotic pairing, system of achiasmate meiosis, holocentric nature of the chromosomes, population structure, and species dispersion patterns, could have contributed to the high level of chromosome rearrangements present in T. bahiensis.

First report of scorpionism caused by Tityus serrulatus, described by Lutz and Mello, 1922 (Scorpiones, Buthidae), a species non-native to the state of Pará, Brazilian Amazon.

This reports a case of scorpionism caused by Tityus serrulatus. A male adult was stung while unloading bananas at the supply center in Belém, Pará, Brazil. The bananas originated in another state (Bahia) and were brought to Belém by truck. The patient presented with pain, edema, and erythema at the sting site, and was classified as low-risk. The specimen was identified as T. serrulatus and symptomatic treatment and clinical observation were advised. The patient was discharged later without further complications. This is the first known envenomation caused by T. serrulatus, a non-native species to Pará, in the Brazilian Amazon.

Influence of different processing techniques on the toxicity and biochemical characteristics of Tityus serrulatus scorpion venom.

Studies of scorpion venoms have used different venom drying methods: lyophilization, desiccation, lyophilization after mixing with 0.9% saline or purified water and centrifugation. The aim of this study was to see if these different approaches cause some alteration in the composition of the venom or interfere with its biological effects. Mice were injected (i.p.) with T. serrulatus scorpion venom in the liquid form (G-liq) or dried by different methods (lyophilized - G-lyo; centrifuged and the supernatant lyophilized - G-cen; desiccated - G-des), and observed regarding the occurrence of the symptoms respiratory difficulty, convulsion and death. The occurrence of seizures, although occurring in all groups and with the various doses used, did not prove to be effective to determine differences between the different handling techniques. Respiratory distress appeared to be useful in analyzing differences between groups, where this effect was less pronounced in the G-liq and G-des groups. In general, death occurred in a certain proportion with increasing dose for all groups. G-liq and G-des seemed to be more "active" at lower doses and G-cen and G-lyo at higher doses. The electrophoretic and chromatographic profile demonstrated main differences between G-liq and the dried groups. In the electrophoretic profile, the liquid venom showed bands of proteins of higher concentration and greater number of major bands and the three dried venom had the lowest number of protein bands. The HPLC profile and densitometry of the electrophoretic profiles showed some differences that may be associated with different protein conformation/aggregation. Our data indicated that lyophilization is the most suitable method for processing T. serrulatus scorpion venom after extraction.

First report of an accident caused by Jaguajir agamemnon (C.L. Koch, 1839) (Scorpiones, Buthidae) in Paraná state, Brazil

ABSTRACT We report the first pediatric case of a Jaguajir agamemnon scorpion sting. This case occurred in the state of Paraná and is the first record of this species in southern Brazil. The patient was admitted within 15 min, with pain, local edema, erythema, whole-body pruritus, and tongue paresthesia within the first two hours, which disappeared thereafter. The patient's condition was considered mild, with a positive outcome, and she recovered completely.

Proteomic endorsed transcriptomic profiles of venom glands from Tityus obscurus and T. serrulatus scorpions.

BACKGROUND: Except for the northern region, where the Amazonian black scorpion, T. obscurus, represents the predominant and most medically relevant scorpion species, Tityus serrulatus, the Brazilian yellow scorpion, is widely distributed throughout Brazil, causing most envenoming and fatalities due to scorpion sting. In order to evaluate and compare the diversity of venom components of Tityus obscurus and T. serrulatus, we performed a transcriptomic investigation of the telsons (venom glands) corroborated by a shotgun proteomic analysis of the venom from the two species. RESULTS: The putative venom components represented 11.4% and 16.7% of the total gene expression for T. obscurus and T. serrulatus, respectively. Transcriptome and proteome data revealed high abundance of metalloproteinases sequences followed by sodium and potassium channel toxins, making the toxin core of the venom. The phylogenetic analysis of metalloproteinases from T. obscurus and T. serrulatus suggested an intraspecific gene expansion, as we previously observed for T. bahiensis, indicating that this enzyme may be under evolutionary pressure for diversification. We also identified several putative venom components such as anionic peptides, antimicrobial peptides, bradykinin-potentiating peptide, cysteine rich protein, serine proteinases, cathepsins, angiotensin-converting enzyme, endothelin-converting enzyme and chymotrypsin like protein, proteinases inhibitors, phospholipases and hyaluronidases. CONCLUSION: The present work shows that the venom composition of these two allopatric species of Tityus are considerably similar in terms of the major classes of proteins produced and secreted, although their individual toxin sequences are considerably divergent. These differences at amino acid level may reflect in different epitopes for the same protein classes in each species, explaining the basis for the poor recognition of T. obscurus venom by the antiserum raised against other species.

Some pharmacological effects of Tityus obscurus venom in rats and mice.

There are a great number of studies about Brazilian scorpions. However, little is known about the venom of scorpions of northern Brazil, mainly about Tityus obscurus, which is responsible for the most number of accidents in the Amazon. Thus, this study aimed to evaluate some pharmacological effects of T. obscurus venom in rats and mice. In rats, the venom (10 mg/kg i.p.) caused hemorrhagic patches in the lung parenchyma but did not lead to pulmonary edema. There was a decrease in general activity, observed in the activity box after venom injection. The venom did not induce changes in the occurrence and intensity of experimentally induced convulsions, nor did it cause hippocampal neuronal loss. In mice, the LD50 obtained was 3.13 mg/kg (i.p.). Different doses of the venom (0.2; 1; 5; 10; 15 µg/30 µL per hind paw) induced edematogenic and moderate nociceptive activity in mice. The Tiyus serrulatus venom used as comparison caused more intense symptomatology in mice. Comparing to the venom of other Tityus scorpions of medical importance, that have convulsant and intense nociceptive effects and cause lung edema, as described in the literature, we can conclude that the venom of T. obscurus probably has different characteristics.

The transcriptome recipe for the venom cocktail of Tityus bahiensis scorpion.

Scorpion venom is a mixture of peptides, including antimicrobial, bradykinin-potentiating and anionic peptides and small to medium proteins, such as ion channel toxins, metalloproteinases and phospholipases that together cause severe clinical manifestation. Tityus bahiensis is the second most medically important scorpion species in Brazil and it is widely distributed in the country with the exception of the North Region. Here we sequenced and analyzed the transcripts from the venom glands of T. bahiensis, aiming at identifying and annotating venom gland expressed genes. A total of 116,027 long reads were generated by pyrosequencing and assembled in 2891 isotigs. An annotation process identified transcripts by similarity to known toxins, revealing that putative venom components represent 7.4% of gene expression. The major toxins identified are potassium and sodium channel toxins, whereas metalloproteinases showed an unexpected high abundance. Phylogenetic analysis of deduced metalloproteinases from T. bahiensis and other scorpions revealed a pattern of ancient and intraspecific gene expansions. Other venom molecules identified include antimicrobial, anionic and bradykinin-potentiating peptides, besides several putative new venom components. This report provides the first attempt to massively identify the venom components of this species and constitutes one of the few transcriptomic efforts on the genus Tityus.

First report of scorpionism caused by Tityus serrulatus, described by Lutz and Mello, 1922 (Scorpiones, Buthidae), a species non-native to the state of Pará, Brazilian Amazon

Abstract This reports a case of scorpionism caused by Tityus serrulatus. A male adult was stung while unloading bananas at the supply center in Belém, Pará, Brazil. The bananas originated in another state (Bahia) and were brought to Belém by truck. The patient presented with pain, edema, and erythema at the sting site, and was classified as low-risk. The specimen was identified as T. serrulatus and symptomatic treatment and clinical observation were advised. The patient was discharged later without further complications. This is the first known envenomation caused by T. serrulatus, a non-native species to Pará, in the Brazilian Amazon.

Uma nova espécie de Tityus C. L. Koch, 1836 (Scorpiones, Buthidae) do estado da Bahia, Brasil / x

Uma nova espécie do gênero Tityus C.L. Koch, 1836 (Scorpiones, Buthidae) é descrita dos municípios de Anagé (36'44''14S - 08'08''41W) e Poções (31'47''14S - 21'55''40W) no estado da Bahia, Brasil. Tityus aba n. sp pertence ao grupo Tityusbahiensis (Lourenço, 2002), caracterizado por espécies de tamanho que variam de cinco a sete cm de comprimento, com colorido variando do amarelo - palha ao marrom avermelhado e sem a lâmina mediana basal dilatada nas fêmeas. Neste grupo, aproxima-se das espécies do complexo Tityusstigmurus (Lourenço, 2001). A nova espécie é mais próxima de Tityus stigmurus (Thorell, 1876), Tityus martinpaechi Lourenço, 2001 e de Tityus melici Lourenço, 2003, distinguindo-se da primeira por apresentar o prossoma quase totalmente negro, maior número de dentes pectíneos e tamanho maior; da segunda por não apresentar manchas nos palpos e pernas, ausência de uma mancha negra de forma triangular sobre o prossoma e também tamanho maior, a da última pela ausência de manchas confluentes no mesossoma e de faixa longitudinal na face ventral dos segmentos de I a IV do metassoma. Tityus aba n.sp. apresenta indivíduos de médio a grande porte, medindo de 6,0 a 7,65 centímetros, de colorido geral castanho claro, com prossoma escuro quase negro e tergitos com três faixas escuras longitudinais, sendo uma mediana e duas laterais; carenas medianas dorsais dos segmentos II a IV com o último granulo maior, tornando-se espiniforme nos segmentos III e IV. Os machos apresentam os palpos mais delgados em relação às fêmeas e os segmentos IV e V do metassoma mais dilatados.

A new species of the genus Tityus C. L. Koch, 1836 (Scorpiones, Buthidae) from the state of Bahia, Brasil. A new species of the genus Tityus C.L.Koch, 1836 (Scorpiones, Buthidae) is described from Anagé (36°44'14"S - 08°08'41"W) and Poções (31°47'14"S - 21°55'40"W), state of Bahia, Brazil. Tityus aba n. sp. belongs to the Tityusbahiensis group Lourenço, 2002 characterized by medium sized specimens, ranging from five to seven cm in length, reddish-brown or brownish coloration patterns and basal middle lamellae of female pectines not dilatated in most species. Within the group, this species is close to the Tityus stigmurus complex and is more related to Tityusstigmurus (Thorell, 1876), Tityusmartinpaechi Lourenço, 2001 and Tityus melici Lourenço, 2003. T. aba n. sp. is distinguished from T. stigmurus by the color of the prossoma, which is almost black, by the higher number of pectinal teeth and by the larger body size. It is distinguished from T. martinpaechi mainly by the absence of dark spots on pedipalps and legs and also by the larger size of the specimens, and from T. melici , by the absence of dark confluent spots over the tergites and longitudinal strip between ventral keels of segments I to IV of the metasoma. Tityus aba n. sp. includes medium to large sized scorpions ranging from 6.0 to 7.65 cm, yellowish brown coloration pattern with an almost black carapace, with three longitudinal dark strips over the tergites, and with the dorsal medial keels of segment II to IV with a larger terminal granule that becomes spinoid on segments III and IV. The males are distinguished from the females by the slender pedipalps and more dilatated metasomal segments IV and V.

Escorpiões: ocorrência das espécies de importância médica, acidentes no Estado de São Paulo, obtenção de veneno e manutenção em cativeiro

Tityus serrulatus Lutz & Mello, 1922 e Tityus bahiensis (Perty, 1933) são responsáveis pela maioria dos acidentes escorpiônicos notificados no Brasil. A picada do escorpião é extremamente dolorosa e pode provocar a morte de seres humanos, principalmente nos acidentes causados por T. serrulatus. O objetivo do trabalho foi determinar quais as melhores condições de cativeiro dos escorpiões T. serrulatus, mantidos no biotério do Laboratório de Artrópodes do Instituto Butantan, bem como a freqüência e intervalo entre as extrações de veneno, visando a obtenção mais eficiente e contínua do mesmo para atender a demanda na produção de soro. Também foram avaliados a ocorrência da espécie T. serrulatus e o domínio desta sobre T. bahiensis no Estado de São Paulo. Os resultados mostraram que quanto menor o intervalo entre as extrações, menos veneno o animal fornece e maior será a mortalidade. Como a quantidade média de veneno, para os animais com intervalo de 90 dias entre as extrações, é mantida na faixa de 0,4 mg por animal, considerado um valor ótimo, se não houver entrada contínua de animais para extração de veneno, é recomendável mantê-los em cativeiro por, no máximo um ano, com extrações a cada 3 meses. Porém, caso haja fluxo contínuo de animais para esta finalidade, eles podem ser extraídos mês a mês e substituídos após 6 meses, uma vez que depois deste período a extração torna-se dispendiosa e improdutiva. T. serrulatus, espécie introduzida no Estado, mostrou ser mais eficiente com relação à dispersão e adaptação em novas localidades. Para T. bahiensis, o total de municípios com a ocorrência do animal passou de 141 para 288, representando um aumento de 104%. Para T. serrulatus, passou de 110 para 352, o que representa um aumento de 220%. A partenogênese, maneira pelo qual T. serrulatus se reproduz, facilita sua dispersão. T. bahiensis, mesmo sendo uma espécie nativa no Estado de São Paulo, ...

Escorpiões: ocorrência das espécies de importância médica, acidentes no Estado de São Paulo, obtenção de veneno e manutenção em cativeiro / Scorpions: occurrence of the medically important species, accidentes in the State of São Paulo, venom extraction and maintenance in capitivity

Tityus serrulatus Lutz & Mello, 1922 e Tityus bahiensis (Perty, 1933) são responsáveis pela maioria dos acidentes escorpiônicos notificados no Brasil. A picada do escorpião é extremamente dolorosa e pode provocar a morte de seres humanos, principalmente nos acidentes causados por T. serrulatus. O objetivo do trabalho foi determinar quais as melhores condições de cativeiro dos escorpiões T. serrulatus, mantidos no biotério do Laboratório de Artrópodes do Instituto Butantan, bem como a freqüência e intervalo entre as extrações de veneno, visando a obtenção mais eficiente e contínua do mesmo para atender a demanda na produção de soro. Também foram avaliados a ocorrência da espécie T. serrulatus e o domínio desta sobre T. bahiensis no Estado de São Paulo. Os resultados mostraram que quanto menor o intervalo entre as extrações, menos veneno o animal fornece e maior será a mortalidade. Como a quantidade média de veneno, para os animais com intervalo de 90 dias entre as extrações, é mantida na faixa de 0,4 mg por animal, considerado um valor ótimo, se não houver entrada contínua de animais para extração de veneno, é recomendável mantê-los em cativeiro por, no máximo um ano, com extrações a cada 3 meses. Porém, caso haja fluxo contínuo de animais para esta finalidade, eles podem ser extraídos mês a mês e substituídos após 6 meses, uma vez que depois deste período a extração torna-se dispendiosa e improdutiva. T. serrulatus, espécie introduzida no Estado, mostrou ser mais eficiente com relação à dispersão e adaptação em novas localidades. Para T. bahiensis, o total de municípios com a ocorrência do animal passou de 141 para 288, representando um aumento de 104%. Para T. serrulatus, passou de 110 para 352, o que representa um aumento de 220%. A partenogênese, maneira pelo qual T. serrulatus se reproduz, facilita sua dispersão. T. bahiensis, mesmo sendo uma espécie nativa no Estado de São Paulo, teve sua distribuição ampliada pelo fato de seu habitat natural estar sendo...