Maik Damm

Ontogenetic shifts in diet are well documented in snakes and are increasingly linked to age-related venom variation. The common adder, Vipera berus, exhibits a dietary transition from predominantly ectothermic prey in its early life to increasingly incorporating endothermic prey as an adult. Here, we investigate whether this dietary shift is reflected in age-related changes in the venom composition and bioactivity of V. berus. Venoms from captive-bred V. berus from Germany were obtained and pooled across five age groups, from neonates to adults. Venom profiles were assessed by SDS-PAGE and genome-guided shotgun proteomics, with quantification based on normalized spectral abundance factors (NSAF) using a toxin-gene catalogue generated from a novel V. berus genome assembly. In parallel, we assayed general protease and PLA2 activities, as well as FXa-, thrombin-, and plasmin-like activities, and cytotoxicity toward mammalian cell lines. We identified two distinct age-related venom phenotypes (ontotypes): an svMP/CTL-rich ontotype A (≤1 year) and an svSP/PLA2-rich ontotype B (≥2 years). Functionally, protease activity decreased with age, whereas thrombin-like, plasmin-like and PLA2 activities, and cytotoxicity, increased. Our findings indicate an ontogenetic shift in composition and activities of V. berus venom that parallels dietary transitions and potentially reflect adaptation to differing prey physiologies.

The Western Hognose snake, Heterodon nasicus , is earth’s most commonly kept venomous pet snake. Generally assumed to be harmless, recent reports suggested a more potent venom than originally thought, but literature is scarce. Here, we analyze the severity of bites among keepers of this species via a retrospective online survey. In 34 reports, symptoms were mentioned. They range from local pain for short time frames to extensive edema that resolve after several days or weeks. Severity was correlated with exposure time to the bite. While symptom resolution time can be long in intense cases, no sequelae or fatalities occur and envenoming can be prevented by simple security measures, such as using gloves. Therefore, we evaluate the venom of H. nasicus to be indeed more damaging than hitherto assumed, yet the species appears to pose no severe danger to humans and we do not see the necessity to impose legal constraints on its role within the pet trade and husbandry.

In zootoxinology, drugs such as anesthetics and secretion enhancers are used to increase venom yields, but it is unclear whether this affects the venom composition. After injection of ketamine and pilocarpine into two non-front-fanged snakes, mass spectrometry confirmed the presence of both drugs and their metabolites in the venoms. The quantified high concentrations raise concerns about potential interference in bioassays and pharmacological studies, highlighting the need to consider extraction additives in venom research to ensure unbiased results.

1 Snakebite is a neglected tropical disease claiming ∼140,000 lives every year. One of the most medically relevant snakes of Asia is the many-banded krait ( Bungarus multicinctus ). Approximately 8% of the global human population is at risk of being envenomated by this species, able to cause fatal neurotoxicity. Here, we present a proteogenomic and functional assessment of the B. multicinctus venom via genome-guided bottom-up and top-down proteomics, combined with protein profiling and bioactivity assays. We report its venom profile alongside the primary structures of its toxins, revealing a relatively simple venom containing 55 components from 16 protein families. It is largely composed by three-finger toxins and phospholipase A ₂ , besides acetylcholinesterase and snake venom metalloprotease. Top-down data unveiled the diversity of the highly lethal β-bungarotoxins and allowed us to infer the complex dimerization patterning of these multi-domain neurotoxins. Our functional analysis revealed that B. multicinctus venom exerts potent phospholipase A ₂ and acetylcholinesterase activities, while protease activity and effects on cell viability and release of second messengers were virtually absent. This suggests, that B. multicinctus venom causes its devastating neurotoxic symptoms due to a heavy reliance on phospholipase A ₂ and acetylcholinesterase, but without directly impairing neuron viability or via interference of second messenger release. Antibacterial and antiviral screens further revealed activity against some pathogenic microbes that warrant further translational investigations. A comparison to previously published venom proteomes of B. multicinctus and its congeners suggests, that intraspecific venom variation occurs more widely in kraits than previously acknowledged and deserves higher attention. Overall, our investigation provides pivotal new insights into the biochemistry and pathophysiology of one of Earth’s most lethal snakes and represents an important resource to inform future proteogenomic and functional studies in krait venom and beyond.

“True” cobras (genus Naja) are among the venomous snakes most frequently involved in snakebite accidents in Africa and Asia. The Cape cobra (Naja nivea) is one of the African cobras of highest medical importance, but much remains to be learned about its venom. Here, we used a shotgun proteomics approach to better understand the qualitative composition of N. nivea venom and tested its cytotoxicity and protease activity as well as its effect on intracellular Ca²⁺ release and NO synthesis. We identified 156 venom components representing 17 protein families, with the dominant ones being three-finger toxins, mostly of the short-chain type. Two-thirds of the three-finger toxin entries identified were assigned as cytotoxins, while the remainder were categorized as neurotoxins, including short-chain, long-chain, and ancestral three-finger toxins. We also identified snake venom metalloproteinases and members of CRISP, l-amino acid oxidase, and other families. Protease activity and its effect on intracellular Ca²⁺ release and NO synthesis were low. Phospholipase A₂ activity was surprisingly high, despite this toxin family being marginally recovered in the analyzed venom. Cytotoxicity was relevant only at higher venom concentrations, with macrophage and neuroblastoma cell lines showing the lowest viability. These results are in line with the predominantly neurotoxic envenomation symptoms caused by Cape cobra bites. The present overview of the qualitatively complex and functionally intriguing venom of N. nivea may provide insights into the pathobiochemistry of this species’ venom.

Snake venom variations are a crucial factor to understand the consequences of snakebite envenoming worldwide, and therefore it is important to know about toxin composition alterations between taxa. Palearctic vipers of the genera Vipera, Montivipera, Macrovipera, and Daboia have high medical impacts across the Old World. One hotspot for their occurrence and diversity is Türkiye, located on the border between continents, but many of their venoms remain still understudied. Here, we present the venom compositions of seven Turkish viper taxa. By complementary mass spectrometry-based bottom-up and top-down workflows, the venom profiles were investigated on proteomics and peptidomics level. This study includes the first venom descriptions of Vipera berus barani, Vipera darevskii, Montivipera bulgardaghica albizona, and Montivipera xanthina, as well as the first snake venomics profiles of Turkish Macrovipera lebetinus obtusa, and Daboia palaestinae, including an in-depth reanalysis of M. bulgardaghica bulgardaghica venom. Additionally, we identified the modular consensus sequence pEXW(PZ)_1-2P(EI)/(KV)PPLE for bradykinin-potentiating peptides in viper venoms. For better insights into variations and potential impacts of medical significance, the venoms were compared against other Palearctic viper proteomes, including the first genus-wide Montivipera venom comparison. This will help the risk assessment of snakebite envenoming by these vipers and aid in predicting the venoms' pathophysiology and clinical treatments.

Background Interdisciplinary approaches are particularly important when it comes to complex research areas such as snakebite envenoming. To achieve the World Health Organization’s (WHO) goal of halving the number of deaths and disabilities from snakebite by 2030, researchers and experts from different fields need to work together. To promote interdisciplinarity in snakebite research and educational work, a one-week hybrid summer school was organised in September 2023 at the Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany. The week’s topics were arranged logically, from snake biology and venomics to clinical implications, new therapeutics and public policy. All lectures were held in English. Methodology/Principal Findings Attendance was recorded for in-person and online participants, transcribed into Excel, and anonymised. Data were then summarised according to the participant’s field of expertise, country of residence, and attendance at each session. Results The summer school successfully promoted interdisciplinarity, with individuals attending from a wide range of scientific fields. However, fluctuations in attendance over the week highlight some challenges in maintaining interdisciplinarity at such events. By mode of attendance, in-person participants attended more of the sessions (76.9%) than those joining in a hybrid format (50.0%) or online only (32.0%). Among those who did not attend all sessions, attendance was highest on Monday (77.6%) and Wednesday (81.3%) but decreased for individuals from all fields over the week. Conclusion/Significance For future international interdisciplinary events, we suggest hybrid events with in-person and online options to encourage more international participation, supported by travel grants. However, the online experience could be improved through online networking and interdisciplinary activities. Future events should also consider hosting events in low- and middle-income countries or satellite locations. An appeal to organizers of future events is that participant data should be collected, analysed and published for continuous improvement of such interdisciplinary events. Author Summary Promoting collaboration between researchers from different disciplines is important for improving the understanding of and ability to tackle complex research areas. However, it is unclear whether courses designed to promote interdisciplinarity are successful or whether interdisciplinarity remains merely a buzzword. To determine the success of interdisciplinary courses and identify areas for improvement, attendance and participant satisfaction during these courses must be assessed. Interdisciplinarity is particularly important for strongly interlinked fields, such as One Health topics involving humans, animals, and the environment. One of these research areas is snakebite envenoming, which poses a health threat to millions of people worldwide. We organised a snakebite summer school in September 2023 to promote interdisciplinarity in this area. The data analysed here shows patterns in participation, highlighting where interdisciplinarity was achieved and where it was lacking. Based on these findings, we recommend hybrid events that allow in-person and online attendance but suggest a range of approaches to improve the experience of online attendees, including providing access to online networking opportunities, and coordination between international organisations to allow for some in-person events in satellite locations for those who are unable to attend the main event location in person.