Venom variability and envenoming severity outcomes of the Crotalus scutulatus scutulatus (Mojave rattlesnake) from Southern Arizona

• Published in: Journal of proteomics 2012-05, Vol.75 (9), p.2576-2587
• Main Authors: Massey, Daniel J., Calvete, Juan J., Sánchez, Elda E., Sanz, Libia, Richards, Kelvin, Curtis, Ryan, Boesen, Keith
• Format: Article
• Language: English
• Subjects: Antivenom; antivenoms; Biological and medical sciences; Crotalus; Crotalus scutulatus; Crotalus scutulatus scutulatus; death; Diverse techniques; Fundamental and applied biological sciences. Psychology; Geographic venom variability; high performance liquid chromatography; lethal dose 50; metalloproteinases; Mojave rattlesnake; Molecular and cellular biology; neurotoxicity; phenotype; polyacrylamide gel electrophoresis; proteome; risk; Snake envenoming; Snake venom; snakes; Venomics; venoms
• ISSN: 1874-3919
• DOI: 10.1016/j.jprot.2012.02.035

Twenty-one Mojave rattlesnakes, Crotalus scutulatus scutulatus (C. s. scutulatus), were collected from Arizona and New Mexico U.S.A. Venom proteome of each specimen was analyzed using reverse-phase HPLC and SDS-PAGE. The toxicity of venoms was analyzed using lethal dose 50 (LD50). Health severity outcomes between two Arizona counties U.S.A., Pima and Cochise, were determined by retrospective chart review of the Arizona Poison and Drug Information Center (APDIC) database between the years of 2002 and 2009. Six phenotypes (A–F) were identified based on three venom protein families; Mojave toxin, snake venom metalloproteinases PI and PIII (SVMP), and myotoxin-A. Venom changed geographically from SVMP-rich to Mojave toxin-rich phenotypes as you move from south central to southeastern Arizona. Phenotypes containing myotoxin-A were only found in the transitional zone between the SVMP and Mojave toxin phenotypes. Venom samples containing the largest amounts of SVMP or Mojave toxin had the highest and lowest LD50s, respectively. There was a significant difference when comparing the presence of neurotoxic effects between Pima and Cochise counties (p=0.001). No significant difference was found when comparing severity (p=0.32), number of antivenom vials administered (p=0.17), days spent in a health care facility (p=0.23) or envenomation per 100,000 population (p=0.06). Although not part of the original data to be collected, death and intubations, were also noted. There is a 10× increased risk of death and a 50× increased risk of intubations if envenomated in Cochise County. [Display omitted] ► Six venom phenotypes were identified in C. s. scutulatus. ► Venom changed geographically from south central to southeastern Arizona. ► SVMP-rich phenotypes have the highest LD50. ► Mojave toxin-rich exhibit the lowest LD50.