Venom comparisons of endemic and micro-endemic speckled rattlesnakes Crotalus mitchellii, C. polisi and C. thalassoporus from Baja California Peninsula.

A high diversity of rattlesnake species can be found in the Baja California peninsula and the island of the Gulf of California, nevertheless, their venom has been poorly evaluated. The aim of this work was to present the first characterization of endemic Crotalus mitchellii, micro endemic C. polisi and C. thalassoporus venoms. All samples provoke human plasma coagulation showing doses in the rank of 2.3-41.0 µg and also produce rapid hydrolysis of the alpha chain of bovine fibrinogen while the beta chain is attacked at larger incubation periods by C. polisi and especially by C. thalassoporus. Phospholipase activity ranging from 23.2 to 173.8 U/mg. The venoms of C. thalassoporus and C. polisi show very high hemorrhagic activity (from 0.03 to 0.31 µg). A total of 130 toxin-related proteins were identified and classified into ten families. Crotalus mitchellii venom was characterized by high abundance of crotoxin-like and other phospholipase proteins (34.5%) and serine proteinases (29.8%). Crotalus polisi showed a similar proportion of metalloproteinases (34%) and serine proteinases (22.8%) components with important contribution of C-type lectins (14.3%) and CRiSP (14.0%) proteins. Venom of C. thalassoporus is dominated by metalloproteases that amount to more than 66% of total toxin proteins. These results provide a foundation for comprehending the biological, ecological and evolutionary significance of venom composition of speckled rattlesnake from the Baja California peninsula.

Epidemiological overview of snakebites in the Baja California peninsula, Mexico (2003-2018).

INTRODUCTION: Ophidian accident is a global public health problem. In Mexico, there is a high incidence of snakebites, which cause medical complications that can leave severe sequelae. OBJECTIVE: To analyze the epidemiological overview of snake venom poisoning in the Baja California (BC) peninsula within the 2003-2018 period. METHOD: A descriptive, retrospective analysis of reported cases was carried out, based on data collection and interpretation. RESULTS: A total of 541 records were obtained, out of which 273 occurred in BC and 268 in Baja California Sur (BCS), with an annual average of 17.06 and 16.75, respectively. The incidence rate for BC was 7.62, while for BCS it was 33.09. The highest annual incidence rate in the state of BC corresponded to southern Ensenada, with a value of 42.3, while in BCS it corresponded to the municipality of Comondú, with a value of 54.04. CONCLUSIONS: Epidemiological analyses allow a better local, state and regional understanding of the problem, in order to develop efficient action protocols to face an ophidian accident, as well as to determine the training requirements of medical personnel and establish a support network for the treatment of cases.

INTRODUCCIÓN: El accidente ofídico es un problema de salud pública mundial. En México existe una alta incidencia de mordeduras por serpientes, que provocan complicaciones médicas que pueden dejar secuelas severas. OBJETIVO: Analizar el panorama epidemiológico del ofidismo en la península de Baja California (BC) en los años 2003-2018. MÉTODO: Se hizo un análisis de tipo descriptivo y retrospectivo de los casos presentados, a partir de la recopilación e interpretación de la información. RESULTADOS: Se obtuvieron 541 registros, de los cuales 273 se presentaron en BC y 268 en Baja California Sur (BCS), con un promedio anual de 17.06 y 16.75 respectivamente. La tasa de incidencia para BC fue de 7.62 y para BCS de 33.09. La tasa de incidencia anual más alta en el Estado de BC correspondió al sur de Ensenada, con un valor de 42.3, mientras que en BCS fue en Comondú, con un valor de 54.04. CONCLUSIONES: Los análisis epidemiológicos permiten tener un mejor entendimiento local, estatal y regional de la problemática, para poder desarrollar protocolos de acción eficientes para enfrentar un accidente ofídico, así como para determinar las necesidades de capacitación del personal médico y establecer una red de ayuda para el tratamiento de casos.

Toxicological comparison of Crotalus ruber lucasensis venom from different ecoregions of the Baja California Peninsula.

The Baja California Peninsula possesses a mosaic of ecoregions that offers a wide variety of environments for the species that here inhabit. Here we report biological variations in. Crotalus ruber lucasensis venom from arid, semiarid and tropical eco-regions. Lethal (1.4-6.8 mg/kg), edematogenic (0.3-0.5 µg) and defibrinogenating (from non-detectable to 20 µg) activities were found to have significant differences among eco-regions.

Comparison of biological and biochemical characteristics of venom from rattlesnakes in the southern Baja California Peninsula.

In Mexico more than 40% of reported snakebites are due to rattlesnake species. In general, the venoms of these snakes are characterized by the presence of highly enzymatic components that could provoke coagulopathies, local and systemic tissue damage and some cases neurotoxicity. In northwestern Mexico (Baja California Peninsula, Gulf of California and Pacific islands), 15 species of Crotalus are distributed. Such a biodiversity implies a high variability in venom compositions that in turns would results in high variability in clinical manifestations. In this work, venoms of Crotalus catalinensis, C. enyo enyo, C. mitchellii mitchellii and C. ruber lucasensis were studied. Lethal doses from 0.35 to 9.21 mg/kg were obtained being venom of C. m. mitchellii the most potent of all. Venoms of C. catalinensis, C. e. enyo and C. r. lucasensis show high hemorrhagic potency (1.34, 1.48 and 1.68 µg respectively). Coagulant activity was found in venoms of C. catalinensis (4.6 µg), C. e. enyo (101.9 µg) and C. m. mitchellii (13.6 µg). Our results point out hemorrhage as one of the most expected signs by three of the four most abundant species in the area. Also, neurotoxicity must be expected by C. m. mitchellii.