Epidemiology of snake envenomation from Mato Grosso do Sul, Brazil

Snake envenomation is considered a public health problem in tropical countries, where they occur in a high incidence. The present study reports the snake envenomation that occurred in Mato Grosso do Sul state (Brazil) between 2007 and 2017. Epidemiological data were obtained from the online platform of the Notification Disease Information System and were analyzed according to biome. A total of 5568 cases of snake envenomations were recorded during the study period, where the highest frequency was registered between October and April. The majority of envenomations occurred in working-age males (20 to 39 years), caused mainly by Bothrops snakes, and the duration of care after the envenomation in most cases took three hours. The municipalities that showed the highest snake envenomations case per 100,000 inhabitants presents low population density, and have their economy based on agricultural activity, which is a risk factor to snake envenomations. To the Mato Grosso do Sul state, the total number of snake envenomations had a positive relationship with the size of the municipality. Since this, larger areas usually have a mosaic of environments, which may harbor higher richness and abundance of snakes, and can cause more snake encounters with the population, resulting in more snake envenomations.

Diagnosis and Treatment of Snake Envenomation in Dogs in Queensland, Australia

Australia has some of the most venous snakes in the world, and envenomations of domestic dogs are common, but clinical signs as well as the diagnostic procedures and treatments of snake envenomations are poorly described. Therefore, we invited veterinary clinics in the state of Queensland, Australia, to provide detailed data on snake envenomation cases in dogs. A total of 230 cases were reported from 19 veterinary hospitals, with an average of 12.1 dogs per clinic, per year. Detailed case data were provided from 20 dogs—of these, 65.0% (13/20) were envenomated during the daytime, with collapse and paresis being the most common signs reported by owners. The median time between the onset of clinical signs and admission to the veterinary hospital was 60 min. Clinical signs were the sole diagnostic modality utilised by veterinarians in 30.0% (6/20) of cases. Activated clotting time was the most common diagnostic procedure conducted, while snake venom detection kits (SVDK) were only used in 15.0% (3/20) of cases. Of the dogs that received antivenom (85.0%, 17/20), the tiger/multibrown combination (3000 units tiger/4000 units brown) was predominately (13/17) provided. Three of the 17 dogs that received antivenom (17.6%) died or were euthanised. About 82.4% (14/17) of the dogs treated with antivenom, but only 33.3% (1/3) of the dogs not treated with antivenom, recovered (p = 0.140). Overall, veterinarians relied frequently on medical history, clinical signs, and diagnostic tests other than the SVDK and, thus, most likely, administered snake envenomation treatment based on their clinical experience.

Venoms and Isolated Toxins from Snakes of Medical Impact in the Northeast Argentina: State of the Art. Potential Pharmacological Applications

: Among the ophidians that inhabit the Northeast of Argentina, the genus Bothrops such as B. alternatus and B. diporus species (also known as yararás) and Crotalus durisus terrificus (named cascabel), represent the most studied snake venom for more than thirty years. These two genera of venomous snakes account for the majority of poisonous snake envenomations and therefore, constitute a medical emergency in this region. This review presents a broad description of the compiled knowledge about venomous snakebite: its pathophysiological action, protein composition, isolated toxins, toxin synergism, toxin-antitoxin cross-reaction assays. Properties of some isolated toxins support a potential pharmacological application.

Interactions between Triterpenes and a P-I Type Snake Venom Metalloproteinase: Molecular Simulations and Experiments

Small molecule inhibitors of snake venom metalloproteinases (SVMPs) could provide a means to rapidly halt the progression of local tissue damage following viperid snake envenomations. In this study, we examine the ability of candidate compounds based on a pentacyclic triterpene skeleton to inhibit SVMPs. We leverage molecular dynamics simulations to estimate the free energies of the candidate compounds for binding to BaP1, a P-I type SVMP, and compare these results with experimental assays of proteolytic activity inhibition in a homologous enzyme (Batx-I). Both simulation and experiment suggest that betulinic acid is the most active candidate, with the simulations predicting a standard binding free energy of Δ G ∘ = − 11.0 ± 1.4 kcal/mol. The simulations also reveal the atomic interactions that underlie binding between the triterpenic acids and BaP1, most notably the electrostatic interaction between carboxylate groups of the compounds and the zinc cofactor of BaP1. Together, our simulations and experiments suggest that occlusion of the S1 ′ subsite is essential for inhibition of proteolytic activity. While all active compounds make hydrophobic contacts in the S1 ′ site, β -boswellic acid, with its distinct carboxylate position, does not occlude the S1 ′ site in simulation and exhibits negligible activity in experiment.