Search

Maintenance of snakes at Butantan Institute started in the last century, intending to produce a different antivenom serum to reduce death caused by snakebites. Through a successful campaign coordinated by Vital Brazil, farmers sent venomous snakes to Butantan Institute by the railway lines with no cost. From 1908 to 1962, the snakes were kept in an outdoor serpentarium, where venom extraction was performed every 15 days. During this period, the snake average survival was 15 days. In 1963, the snakes were transferred to an adapted building, currently called Laboratory of Herpetology (LH), to be maintained in an intensive system. Although the periodicity of venom extraction remained the same, animal average survival increased to two months. With the severe serum crisis in 1983, the Ministry of Health financed remodeling for the three public antivenom producers, and with this support, the LH could be improved. Air conditioning and exhausting systems were installed in the rooms, besides the settlement of critical hygienic-sanitary managements to increase the welfare of snakes. In the early 1990s, snake survival was ten months. Over the years to the present day, several improvements have been made in the intensive serpentarium, as the establishment of two quarantines, feeding with thawed rodents, an interval of two months between venom extraction routines, and monitoring of snake health through laboratory tests. With these new protocols, average snake survival increased significantly, being eight years for the genus Bothrops , ten years for genus Crotalus and Lachesis, and four years for the genus Micrurus . Aiming the production of venoms of good quality, respect for good management practices is essential for the maintenance of snakes in captivity. New techniques and efficient management must always be sought to improve animal welfare, the quality of the venom produced, and the safety of those working directly with the venomous snakes., Competing Interests: Competing interests: The authors declare that they have no competing interests.

Background: Lack of complete genomic data of Bothrops jararaca impedes molecular biology research focusing on biotechnological applications of venom gland components. Identification of full-length coding regions of genes is crucial for the correct molecular cloning design., Methods: RNA was extracted from the venom gland of one adult female specimen of Bothrops jararaca . Deep sequencing of the mRNA library was performed using Illumina NextSeq 500 platform. De novo assembly of B. jararaca transcriptome was done using Trinity. Annotation was performed using Blast2GO. All predicted proteins after clustering step were blasted against non-redundant protein database of NCBI using BLASTP. Metabolic pathways present in the transcriptome were annotated using the KAAS-KEGG Automatic Annotation Server. Toxins were identified in the B. jararaca predicted proteome using BLASTP against all protein sequences obtained from Animal Toxin Annotation Project from Uniprot KB/Swiss-Pro database. Figures and data visualization were performed using ggplot2 package in R language environment., Results: We described the in-depth transcriptome analysis of B. jararaca venom gland, in which 76,765 de novo assembled isoforms, 96,044 transcribed genes and 41,196 unique proteins were identified. The most abundant transcript was the zinc metalloproteinase-disintegrin-like jararhagin. Moreover, we identified 78 distinct functional classes of proteins, including toxins, inhibitors and tumor suppressors. Other venom proteins identified were the hemolytic lethal factors stonustoxin and verrucotoxin., Conclusion: It is believed that the application of deep sequencing to the analysis of snake venom transcriptomes may represent invaluable insight on their biotechnological potential focusing on candidate molecules., Competing Interests: Competing interests: The authors declare no potential competing interests.

Background: Variability in snake venoms is a well-studied phenomenon. However, sex-based variation of Bothrops atrox snake venom using siblings is poorly investigated. Bothrops atrox is responsible for the majority of snakebite accidents in the Brazilian Amazon region. Differences in the venom composition of Bothrops genus have been linked to several factors such as ontogeny, geographical distribution, prey preferences and sex. Thus, in the current study, venom samples of Bothrops atrox male and female siblings were analyzed in order to compare their biochemical and biological characteristics., Methods: Venoms were collected from five females and four males born from a snake captured from the wild in São Bento (Maranhão, Brazil), and kept in the Laboratory of Herpetology of Butantan Intitute. The venoms were analyzed individually and as a pool of each gender. The assays consisted in protein quantification, 1-DE, mass spectrometry, proteolytic, phospholipase A 2 , L-amino acid oxidase activities, minimum coagulant dose upon plasma, minimum hemorrhagic dose and lethal dose 50%., Results: Electrophoretic profiles of male's and female's venom pools were quite similar, with minor sex-based variation. Male venom showed higher LAAO, PLA 2 and hemorrhagic activities, while female venom showed higher coagulant activity. On the other hand, the proteolytic activities did not show statistical differences between pools, although some individual variations were observed. Meanwhile, proteomic profile revealed 112 different protein compounds; of which 105 were common proteins of female's and male's venom pools and seven were unique to females. Despite individual variations, lethality of both pools showed similar values., Conclusion: Although differences between female and male venoms were observed, our results show that individual variations are significant even between siblings, highlighting that biological activities of venoms and its composition are influenced by other factors beyond gender., Competing Interests: Competing interests: The authors declare that they have no competing interests.

Background: Bothrops atrox is known to be the pit viper responsible for most snakebites and human fatalities in the Amazon region. It can be found in a wide geographical area including northern South America, the east of Andes and the Amazon basin. Possibly, due to its wide distribution and generalist feeding, intraspecific venom variation was reported by previous proteomics studies. Sex-based and ontogenetic variations on venom compositions of Bothrops snakes were also subject of proteomic and peptidomic analysis. However, the venom peptidome of B. atrox remains unknown., Methods: We conducted a mass spectrometry-based analysis of the venom peptides of individual male and female specimens combining bottom-up and top-down approaches., Results: We identified in B. atrox a total of 105 native peptides in the mass range of 0.4 to 13.9 kDa. Quantitative analysis showed that phospholipase A 2 and bradykinin potentiating peptides were the most abundant peptide families in both genders, whereas disintegrin levels were significantly increased in the venoms of females. Known peptides processed at non-canonical sites and new peptides as the Ba1a, which contains the SVMP BATXSVMPII1 catalytic site, were also revealed in this work., Conclusion: The venom peptidomes of male and female specimens of B. atrox were analyzed by mass spectrometry-based approaches in this work. The study points to differences in disintegrin levels in the venoms of females that may result in distinct pathophysiology of envenomation. Further research is required to explore the potential biological implications of this finding., Competing Interests: Competing interests: The authors declare that they have no competing interests.

Background: South American rattlesnakes are represented in Brazil by a single species, Crotalus durissus , which has public health importance due to the severity of its envenomation and to its wide geographical distribution. The species is subdivided into several subspecies, but the current classification is controversial. In Brazil, the venoms of C. d. terrificus and C. d. collilineatus are used for hyperimmunization of horses for antivenom production, even though the distinction of these two subspecies are mostly by their geographical distribution. In this context, we described a comparative compositional and functional characterization of individual C. d. collilineatus and C. d. terrificus venoms from three Brazilian states., Methods: We compared the compositional patterns of C. d. terrificus and C. d. collilineatus individual venoms by 1-DE and RP-HPLC. For functional analyzes, the enzymatic activities of PLA 2 , LAAO, and coagulant activity were evaluated. Finally, the immunorecognition of venom toxins by the crotalic antivenom produced at Butantan Institute was evaluated using Western blotting., Results: The protein profile of individual venoms from C. d. collilineatus and C. d. terrificus showed a comparable overall composition, despite some intraspecific variation, especially regarding crotamine and LAAO. Interestingly, HPLC analysis showed a geographic pattern concerning PLA 2 . In addition, a remarkable intraspecific variation was also observed in PLA 2 , LAAO and coagulant activities. The immunorecognition pattern of individual venoms from C. d. collilineatus and C. d. terrificus by crotalic antivenom produced at Butantan Institute was similar., Conclusions: The results highlighted the individual variability among the venoms of C. durissus ssp. specimens. Importantly, our data point to a geographical variation of C. durissus ssp. venom profile, regardless of the subspecies, as evidenced by PLA 2 isoforms complexity, which may explain the increase in venom neurotoxicity from Northeastern through Southern Brazil reported for the species., Competing Interests: Competing interests: The authors declare that they have no competing interests.

Background: Crotalus durissus is considered one of the most important species of venomous snakes in Brazil, due to the high mortality of its snakebites. The venom of Crotalus durissus contains four main toxins: crotoxin, convulxin, gyroxin and crotamine. Venoms can vary in their crotamine content, being crotamine-negative or -positive. This heterogeneity is of great importance for producing antivenom, due to their different mechanisms of action. The possibility that antivenom produced by Butantan Institute might have a different immunorecognition capacity between crotamine-negative and crotamine-positive C. durissus venoms instigated us to investigate the differences between these two venom groups., Methods: The presence of crotamine was analyzed by SDS-PAGE, western blotting and ELISA, whereas comparison between the two types of venoms was carried out through HPLC, mass spectrometry analysis as well as assessment of antivenom lethality and efficacy., Results: The results showed a variation in the presence of crotamine among the subspecies and the geographic origin of snakes from nature, but not in captive snakes. Regarding differences between crotamine-positive and -negative venoms, some exclusive proteins are found in each pool and the crotamine-negative pool presented more phospholipase A 2 than crotamine-positive pool. This variation could affect the time to death, but the lethal and effective dose were not affected., Conclusion: These differences between venom pools indicate the importance of using both, crotamine-positive and crotamine-negative venoms, to produce the antivenom., Competing Interests: Competing interests: The authors declare that they have no competing interests.