captive-maintenance-venom-extraction-tityus-serrulatus-brazilian

Captive Maintenance and Venom Extraction of <em>Tityus serrulatus</em> (Brazilian Yellow Scorpion) for Antivenom Production

Scorpion envenomation is a public health problem in several tropical and subtropical countries. Tityus serrulatus Lutz and Mello, 1922 (Brazilian yellow ...

Instituto Butantan

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.

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

Scorpionism is a relevant public health problem in several countries in tropical and subtropical regions. In Brazil, Tityus serrulatus sting can induce acute lung injury in part as a consequence of inflammation. Despite the occurrence of other scorpions of Tityus genus in Brazilian scorpiofauna, the knowledge regarding pulmonary alterations is related to T. serrulatus venom (Tsv). Here we studied, comparatively, the pathophysiological changes in the rat airways envenomed by Tsv or T. bahiensis venom (Tbv), since both scorpions are involved in human accidents but with severe envenomations occurring when victims are stung by T. serrulatus. After intravenous injection of the venoms (200 μg/kg), both were able to induce Evans blue extravasation (in 30 min) into airways and increased protein extravasation into lungs at 4 and 24 h, but the magnitude of such events was higher in Tsv group. Hemorrhage (in 60 min) in the lungs was higher in Tbv group, while IL-1β (at 1 h) and IL-6 (at 1 and 4 h) in lung homogenates were detected only in Tsv group. Four and 24 h after envenomation, myeloperoxidase activity in lung was equally augmented in the envenomed groups, as well as an increased in polymorphonuclear cell numbers in bronchoalveolar lavage fluid. At 4 h blood leukogram showed increased leukocyte values with the highest neutrophilia in Tsv group. The numbers of leukocytes and neutrophils remained higher than control at 24 h in Tsv and Tbv groups, and it was accompanied by lympho (envenomed groups) and monocytosis (Tsv group). In conclusion, although Tbv was capable of inducing acute lung injury and blood leukocyte mobilization, most of the evaluated parameters were more affected by the Tsv. These results could help to explain the pathophysiology of the scorpionism and the clinical data arguing toward the greatest severity associated with T. serrulatus stings.

A comparative study of pathophysiological alterations in scorpionism induced by Tityus serrulatus and Tityus bahiensis venoms.

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.

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

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.

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.

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.

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

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.

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

Tityus obscurus has caused mild, moderate and severe accidents of medical relevance in the eastern Brazilian Amazon and French Guiana. Tityus obscurus has sexual dimorphism although males and females have uniform black coloration. In the Amazon, one of the habitats of this scorpion is seasonally flooded forests (igapós and várzeas). However, most stings occur in terra firme forest areas (non-flooded region), where most rural communities are located. Adults and children stung by T. obscurus may experience an "electric shock" sensation for more than 30 h after the sting. Our data shows that people inhabiting remote forest areas, including rubber tappers, fishermen and indigenous people, with no access to anti-scorpion serum, use parts of native plants, such as seeds and leaves, against pain and vomiting caused by scorpion stings. Although there is a technical effort to produce and distribute antivenoms in the Amazon, many cases of scorpion stings are geographically unpredictable in this region, due to the lack of detailed knowledge of the natural distribution of these animals. In this manuscript, we compile information on the natural history of T. obscurus and the impact of its envenoming on human health. We identify the natural sites that host this scorpion in the Amazon, in order to warn about the risk of human envenoming. The use of specific antivenom serum is the recommended treatment for accidents involving venomous animals. However, atypical symptoms not neutralized by the available commercial antivenom are reported in the Amazon region. Facing this scenario, we present some challenges to the study of venomous animals in the Amazon rainforest and possible experimental bottlenecks and perspectives for establishing a method aimed at producing an efficient antivenom.

On the noxious black Amazonian scorpion, Tityus obscurus (Scorpiones, Buthidae): Taxonomic notes, biology, medical importance and envenoming treatment.

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.

Denise M. Candido

Bioindustrial Center

Instituto Butantan

Captive Maintenance and Venom Extraction of Tityus serrulatus (Brazilian Yellow Scorpion) for Antivenom Production