Snakebite epidemiology in the State of Mexico, Mexico 2003-2024

Posted by
  Snakebite epidemiology in the State of Mexico, Mexico 2003-2024 Abstract In the State of Mexico, several venomous snakes have low median lethal doses, which therefore pose serious health risks. We analyzed the epidemiology of snakebites from 2003 to 2024 and examined their relationship with demographic, socioeconomic, and biological factors. Incidence rates and demographic characteristics were calculated, and Getis-Ord Gi* statistics were used to identify snakebite hotspots. We also applied Non-Metric Multi-Dimensional Scaling (NMDS) to explore associations between hotspot categories and socioeconomic conditions. The potential distribution of 14 venomous snake species was modelled to estimate venomous snake diversity across municipalities. A total of 3,972 cases were reported, with an increasing trend over time. Most bites occurred in summer, affecting mainly males aged 25-44. Hotspot analysis identified 27 municipalities as hotspots, 50 as not significant and 48 as coldspots. So...

Spider peptides from Brachypelma smithi with slightly different amino acids at their C-terminal loops exert different insecticidal activities

Posted by

 

Image Credit: Public Domain

Spider peptides from Brachypelma smithi with slightly different amino acids at their C-terminal loops exert different insecticidal activities

Abstract

The insecticidal molecules of spiders persistently evolve to ensure rapid paralysis of their prey, and the best molecules are transmitted to their progeny. Here, we cloned two insecticidal peptides, Bs2 and Bs3, from the venom glands of the theraphosid Brachypelma smithi. Bs2 and Bs3 are 90.2% identical, but they exhibit interesting structural differences at their C-termini, including a connecting disulfide bond (residues Cys15-Cys36 for Bs2 and Cys15-Cys30 for Bs3). The genomic origin of Bs2 and Bs3 may be a cause for gene duplication events. Moreover, Bs2 differs in two residues from Tal1 (95.1% identical), an insecticidal peptide, from the tarantula Tliltocatl albopilosus. Likewise, Bs3 is similar to Asp3a from Aphonopelma sp., a peptide that targets mammalian Cav (voltage-dependent Ca2 + channel), but it has not been tested in insects. Bs2 and Bs3 were cloned and recombinantly expressed in bacterial cells, and their paralytic effects were tested on three species of insects. The insecticidal peptide rBs2 with the connecting loop Cys15-Cys36 was significantly more insecticidal than that of rBs3 when affecting Galleria mellonella larvae (Lepidoptera). Yet, the insecticidal peptide rBs3 with the connecting loop Cys15-Cys30 was significantly more insecticidal than that of rBs2 when affecting Acheta domesticus nymph crickets (Orthoptera), and Gromphadorhina portentosa cockroaches (Blattodea). rBs2 and rBs3 structural models show a low-structured C-terminal in rBs3, which correlates with a more flexible amino acid sequence of such C-terminal from residues Tyr30 to Leu42. Since insecticidal spider peptides are constantly evolving for prey capture, they are valuable ion channel antagonists for understanding insect cell receptors, and they are also promising leads for insect control.

Clement, H., Corrales-García, L., Carpanta, V. et al. Spider peptides from Brachypelma smithi with slightly different amino acids at their C-terminal loops exert different insecticidal activities. Amino Acids (2026). https://doi.org/10.1007/s00726-026-03521-5