The Bold and the Beautiful: a Neurotoxicity Comparison of New World Coral Snakes in the Micruroides and Micrurus Genera and Relative Neutralization by Antivenom

Coral snake envenomations are well characterized to be lethally neurotoxic. Despite this, few multispecies, neurotoxicity and antivenom efficacy comparisons have been undertaken and only for the Micrurus genus; Micruroides has remained entirely uninvestigated. As the USA’s supplier of antivenom has currently stopped production, alternative sources need to be explored. The Mexican manufacturer Bioclon uses species genetically related to USA species, thus we investigated the efficacy against Micrurus fulvius (eastern coral snake), the main species responsible for lethal envenomations in the USA as well as additional species from the Americas. The use of Coralmyn® coral snake antivenom was effective in neutralizing the neurotoxic effects exhibited by the venom of M. fulvius but was ineffective against the venoms of Micrurus tener, Micrurus spixii, Micrurus pyrrhocryptus, and Micruroides euryxanthus. Our results suggest that the Mexican antivenom may be clinically useful for the treatment of M. fulvius in the USA but may be of only limited efficacy against the other species studied.