Antigenic cross-reactivity among components of Brazilian Elapidae snake venoms

Snake venoms from M. corallinus (LD5=7.1 + or - 0.83 µg), M.frontalis (LD50=19.3 + or - 3.13 µg), M. ibiboboca (LD50=19.8 + or - 2.07 µg) and M. spiixi (LD50=6.7 + or - 1.25 µg) (family Elapidae, genus Micrurus) injected into horses alone or in combination (M. corallinus with M. frontalis) elicit antibody production, as indicated in vivo by neutralization of venom lethality and in vitro by enzyme-linked immunosorbent assay (ELISA), immunoelectrophoresis (IE) and Western blotting (WB). Venom lethality was efficiently neutralized by the antisera, with the monovalent antivenoms being more efficient than the bivalent antivenom. Antibodies against venom components were detected by all artisera at different titers by ELISA. Upon IE, antisera against M. spiixi and M. frontalis venoms cross-reacted with the four types of venoms studied and recognized several molecular components, the precipitin lines obtained had distinct intensities and electrophoretic motilities, whereas the antivenom against M. corallinus only recognized components of its venom but not of the others. All antivenoms cross-reacted with all the elapid venoms in WB revealing several blands with distinct MWs in M. corallinus and M. spiixi venoms, two very sharp and separate bands in M. corallinus venom and a very sharp band of high MW together with several other smaller and faint bands in M. frontalis venom. The data indicate that snake venoms of the genus Micrurus are good immunogens that contain many cross-reactive molecules, and that their toxic components are neutralized more effectively by monovalent rather than by bivalent antivenom

Neutralization of coral snake Micrurus nigrocinctus venom by a monovalent antivenom

The neutralizing ability of a monovalent anti-Micrurus nigrocinctus (coral snake) antivenom produced in Costa Rica was tested against the letal, myotoxic and phospholipase A, activities of homologous venom. In addition, immunodiffusion and Western blot analyses were performed. in experiments where venom and antivenom were incubated prior to the test, antivenom was effective in neutralizing lethal, myotoxic and phospholipase A2, activities, with Effective Doses 50% of 2700 *l antivenom/mg venom, 1840 *l antivenom/mg venom, and 3630 *l antivenom, respectively. When coral snake antivenom was administered different times after coral snake venom injection, neutralization of lethality was achieved ehen antivenom was injected iv immediately and 15 min after venom. In contrast, lethaly was not reduced when antivenom was administered by the route. Only partial neutralization of myotoxixity was observed even when antivenom was injected iv immediately after envenomation. Immunodiffusion and immunoblot analyses demonstrated the presence of antibodies in antivenom against several, but not all, venom components

A double antibody sandwich micro-ELISA kit for the rapid diagnosis of snake bite.

A micro ELISA assay was established to diagnose systemic poisoning for the rapid administration of specific antivenom. Rabbit anti venom IgG was bound to the solid phase to enable detection of venom from both the Malayan Pit Viper (Agkistrodon rhodostoma) and the Common Cobra (Naja naja). This assay is read visually and takes 35 to 45 minutes to perform. It can detect 15.6 ng/ml of viper venom in 75 minutes and 7.8 ng/ml of cobra venom in 55 minutes. Tests on sera from snake bite patients showed detectable levels of snake venom in the serum even though administration of antivenom was not necessary. Furthermore, results from these clinical cases were obtained in less than 45 minutes. It was found that the most suitable washing media was saline/Tween, the assay could be performed at room temperature and plates stored for 6 months showed no loss of activity.