Antivenomics as a tool to improve the neutralizing capacity of the crotalic antivenom: a study with crotamine

Abstract

BackgroundSnakebite treatment requires administration of an appropriate antivenom that should contain antibodies capable of neutralizing the venom. To achieve this goal, antivenom production must start from a suitable immunization protocol and proper venom mixtures. In Brazil, antivenom against South American rattlesnake (Crotalus durissus terrificus) bites is produced by public institutions based on the guidelines defined by the regulatory agency of the Brazilian Ministry of Health, ANVISA. However, each institution uses its own mixture of rattlesnake venom antigens. Previous works have shown that crotamine, a toxin found in Crolatus durissus venom, shows marked individual and populational variation. In addition, serum produced from crotamine-negative venoms fails to recognize this molecule.MethodsIn this work, we used an antivenomics approach to assess the cross-reactivity of crotalic antivenom manufactured by IVB towards crotamine-negative venom and a mixture of crotamine-negative/crotamine-positive venoms.ResultsWe show that the venom mixture containing 20% crotamine and 57% crotoxin produced a strong immunogenic response in horses. Antivenom raised against this venom mixture reacted with most venom components including crotamine and crotoxin, in contrast to the antivenom raised against crotamine-negative venom.ConclusionsThese results indicate that venomic databases and antivenomics analysis provide a useful approach for choosing the better venom mixture for antibody production and for the subsequent screening of antivenom cross-reactivity with relevant snake venom components.

Pharmacological characterization of crotamine effects on mice hind limb paralysis employing both ex vivo and in vivo assays: Insights into the involvement of voltage-gated ion channels in the crotamine action on skeletal muscles

“…Although the urine darkness, popularly described as ‘coke-like urine’, was first associated to possible hemolytic or kidney damage action of the toxins present in the rattlesnake venom, it is now recognized that in human, this is more likely determined by the myotoxic effects as rhabdomyolysis, which can eventually determine the kidney injuries [ 1 , 36 ]. All these effects have been mainly associated to the action of the neurotoxin crotoxin (phospholipase A2), also considered as the most lethal component of the rattlesnake venom (with estimated LD 50 values between 60 and 180 μg/kg of BW in mice, depending on the administration route) [ 1 , 37 , 38 ]. Crotoxin is far more toxic than crotamine, which LD 50 was described to be of about 0.07 to 6 mg/kg of BW, also depending on the administration route [ 5 , 7 , 8 , 9 ].…”

Evaluating the Immunological cross-reactivity of Indian polyvalent antivenoms towards the venom of Hypnale hypnale (hump-nosed pit viper) from the Western Ghats

“…Similar trend was noticed in detecting SSV venom epitopes also. As stated above, the differences in the antivenom neutralization efficiencies against HPV and SSV venom might be contributed by the antivenom production and purification protocols and the variation in the venom antigens that were used for immunizing horses while generating polyvalent antivenoms [16,17].…”

Antivenomic approach of different Crotalus durissus collilineatus venoms

“…Boldrini-França et al reported that crotamine was not recognized by the anticrotalic sera produced by Instituto Vital-Brazil and Instituto Butantan [ 47 ], which may have led to improvements in the crotalic AV production in Brazil. Due to this lack of crotamine neutralization, Teixeira-Araújo et al established a new protocol to anticrotalic serum production by Instituto Vital-Brazil , using crotamine-positive and negative crotalic venom in the same proportion for horses immunization, which resulted in the recognition of crotamine by the new AV [ 48 ]. While in Instituto Butantan , according to the institution, a mixture of equal amounts of C. d. terrificus and C. d. collilineatus venoms collected in different regions of Brazil is used to the antivenom production.…”