Colubrid Envenomations in the United States

Abstract

The literature concerned with colubrid envenomations in the United States is reviewed, including cases involving Americans who were envenomated by exotic snakes. Because exotic snakes have become readily available through the pet trade, it is essential for medical personnel to realize that snake-bite victims presenting themselves at North American hospitals may have been bitten by South American, Asian, African or European animals. Major themes emerging from this review are: 1) some colubrid envenomations have been serious, even life threatening, 2) many so-called envenomations might actually be allergic reactions, 3) extreme variability seems to characterize Duvernoy's secretions, intraspecifically as well as interspecifically, 4) even within the same individual, Duvernoy's secretion can vary in composition and action from time to time, and 5) we know little about the determinants of this variability, although a variety of hypotheses are available. Opportunities for research in this area are extensive. Likewise, we know little about the historical or current biological role(s) of Duvernoy's secretions, and once again there exists a plethora of hypotheses, only a few of which have been tested. We appear to be standing at the threshold of a new era of exciting empirical and theoretical discoveries, some of which may redefine the way we think about colubrid oral secretions.

Analysis of Colubroidea snake venoms by liquid chromatography with mass spectrometry: evolutionary and toxinological implications

“…The origin of venom‐delivery systems in snakes has been a subject of much research and debate,2,7,8 with present opinion favoring an early origin of venom at the base of the colubroid radiation, followed by extensive ‘evolutionary tinkering’ (Vidal,2 but see Chiszar and Smith9 for contrasting views). The ‘early origin’ hypothesis was recently reinforced by us through the isolation of a three‐finger toxin (3FTx) from the colubrine Coelognathus radiatus , and a phylogenetic analysis showing that this gene family diverged before some of the most basal lineage splits within the Colubroidea 10…”

Full-Length Venom Protein cDNA Sequences from Venom-Derived mRNA: Exploring Compositional Variation and Adaptive Multigene Evolution

“…Rear-fanged snake venoms have not been as well-studied as front-fanged snake venoms, largely due to the difficulties extracting venoms from these snakes and the fact that the large majority of envenomations from these snakes are not life threatening [ 38 – 41 ]. However, rear-fanged snake venoms potentially contain proteins that could serve as novel pharmaceutical drug leads or in other applications, such as proteolytic enzymes for protein fragmentation for mass spectrometry [ 42 , 43 ].…”

Venom proteomes of South and North American opisthoglyphous (Colubridae and Dipsadidae) snake species: A preliminary approach to understanding their biological roles

“…Hypsiglena (family Dipsadidae) and Trimorphodon (family Colubridae) (Quijada-Mascareñas and Wüster, 2010), along with other genera of North American rear-fanged snakes, also have caused envenomations (Chiszar and Smith, 2002). Hypsiglena torquata is a small nocturnal rear-fanged snake that is found from southwestern Canada through much of the western United States to Baja California and the Mexican state of Guerrero (Rodriguez-Robles et al, 1999).…”

“…Trimorphodon biscutatus is also a nocturnal rear-fanged snake, widespread in the deserts of the southwestern United States and northwestern Mexico (Goldberg, 1995). Both species are capable of causing envenomation in humans, inducing localized effects characterized by pain, edema, lymphadenopathy and ecchymosis; therefore, these bites have similar characteristics to those by small Viperidae (Chiszar and Smith, 2002). In addition, bites by Hypsiglena to other snakes can produce hemorrhagic lesions and fatalities (Hill and Mackessy, 2000).…”