# Consistent Killers: Conservation of Thrombin-Like Action on Fibrinogen by Bushmaster (Lachesis Species) Venoms Underpins Broad Antivenom Cross-Reactivities

## TL;DR

Venoms from different Bushmaster snakes consistently affect blood clotting, and two antivenoms effectively neutralize these effects across regions.

## Contribution

The study reveals a conserved thrombin-like venom activity across Lachesis species and antivenom cross-reactivity.

## Key findings

- Venoms from L. muta and L. stenophrys show consistent pseudo-procoagulant activity on human plasma and fibrinogen.
- PoliVal-ICP and Antivipmyn-Tri antivenoms effectively neutralize venom effects across species and localities.
- ICP antivenom demonstrated the highest neutralization capacity.

## Abstract

Snakebite represents a significant public health challenge in Central and South America, with Lachesis (Bushmaster) species posing unique clinical challenges due to their severe envenomation effects arising from a combination of potent venom and copious venom yields. Using in vitro coagulation assays, we analyzed the coagulotoxic venom effects from four distinct localities: L. muta from Surinam and French Guiana and L. stenophrys from Costa Rica and Panama. This study examined the venom’s impact on human plasma and fibrinogen and evaluated the efficacy of two regionally available antivenoms (PoliVal-ICP and Antivipmyn-Tri) in neutralizing the pathophysiological effects. Our results demonstrated a remarkable consistency in the pseudo-procoagulant venom activity (also known as: thrombin-like) across different species and localities. Antivenom efficacy testing revealed that both the PoliVal-ICP and Antivipmyn-Tri antivenoms effectively neutralized the venom effects across localities for both species, with the ICP antivenom showing the highest neutralization capacity. These toxicology findings highlight the biochemical conservation of venom composition across Lachesis species which underpins effective cross-neutralization in antivenom treatment.