Comparative study of venom of Bothrops and Crotalus snake neonates from Instituto Butantan stock

• Grant number: 19/27153-8
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: October 01, 2020
• End date: August 31, 2021
• Field of knowledge: Biological Sciences - Zoology - Physiology of Recent Groups
• Principal Investigator: Anita Mitico Tanaka-Azevedo
• Grantee: Daniel Carvalho de Souza
• Host Institution: Instituto Butantan. Secretaria da Saúde (São Paulo - Estado). São Paulo , SP, Brazil

Abstract

Snakes of Bothrops genus and Crotalus durissus terrificus subspecies are of great medical importance in Brasil due to the high rate of snakebite accidents in the country. The complex mixture of enzymes from the families of phospholipase-A2, metalloproteases and serinoproteases is responsible for the myotoxic, hemorrhagic and coagulating disorders caused by the botropic venom, while the crotoxin enzymatic complex is the main responsible for neurotoxicity and higher mortality in crotalic envenoming. Understanding the ontogenetic variation in snake venom is essential for effectiveness in treating envenomation. This variation occurs from the genetic control and selective pressure of adaptation of snakes to their ecological niche. Post-translational modifications, such as N-glycosylation, also play an important role in modifying the structure and activity of enzymes present in the venom of neonates and adults. Phospholipases-A2 and proteases, commonly identified as markers of ontogenetic variation; and conserved enzymes, such as L-amino acid oxidases, are essential tools to understand the variability trends in botropic and crotalic venom. The lower immunoreactivity of antibotropic commercial serum in neonates of medically important snakes, especially B. jararaca, and the survey by Hospital Vital Brasil (São Paulo) that snake envenoming is caused mainly by female and juvenile snakes demonstrate that ontogeny cannot be neglected when analyzing the issue of snakebite in Brazil. Thus, this research seeks to analyze the inter and intraspecific variability in the profile and enzymatic activity of the venom of neonates of snakes of the genus Bothrops and subspecies C. d. terrificus, and its effect on the neutralization of the venom of these species by commercial antibotropic and anticrotalic serum.