Micrurus Species Research Articles

Local effects induced by venoms from five species of genus Micrurus sp. (coral snakes)

Venoms from five species of Micrurus (coral snakes) from Brazil (Amazonas State) were tested for the following effects: edematogenic, myotoxic, coagulant, hemorrhagic and phospholipase A2 (PLA2) detection. None of the venoms tested presented coagulant activity. The presence of PLA2 was detected by ELISA in the venoms of M. spixii, M. averyi and M. lemniscatus. The myotoxicity was estimated by the increase in the serum creatine kinase level and by histological analysis. All venoms, except that from M. surinamensis, induced intense edematogenic and myotoxic effects. The venom of M. averyi showed hemorrhagic activity which was confirmed by histopathological analysis. This is the first evidence of such an effect by coral snake venom.

Karyotypes of Five Species of Coral Snakes (Micrurus)

There are more than 50 species of coral snakes classified in the genera Micrurus and Micruroides (Roze, 1982). The evolutionary relationships within this group, as well as between coral snakes and Old World elapids, have been studied only to a partial extent. Most studies have been based on morphological analyses (e.g., Savage and Vial, 1973; Roze, 1982), although immunochemical comparisons of serum albumins have also been used (Cadle and Sarich, 1981; Cadle and Gorman, 1981). Chromosome studies have shown extensive karyotype variation between elapid species (Singh, 1972a; Singh, 1974; Graham, 1977; Gutierrez and Bolafios, 1979; Gorman, 1981). Thus, karyology may become a useful tool in understanding the phylogenetic relationships among elapid snakes in general, and within coral snakes in particular. Karyotypes of five species of Micrurus have been reported: M. lemniscatus (Becak and Becak, 1969), M. fulvius (Graham, 1977), M. nigrocinctus, M. alleni, and M. mipartitus (Gutierrez and Bolafios, 1979, 1981). In this work we describe the karyotypes of five additional species of Micrurus: M. elegans, M. diastema, M. hippocrepis, M. browni, and M. surinamensis. To obtain the karyotypes, the method of Gutierrez and Bolafios (1979), based on the simultaneous injection of phytohemagglutinin and colchicine, was used. From each species, at least 30 mitotic figures were studied to determine the diploid number; from these, four were selected and photographed to prepare idiograms. Chromosomes were classified using the nomenclature proposed by Levan et al. (1964). The Nombre Fondamentale (NF) was defined as the number of arms of the macrochromosomes. The specimens used in this study were collected in the following locations: M. browni, two males from Volcan de Agua, Guatemala; M. diastema sapperi, one male from Izabal, Guatemala; M. diastema apiatus, one female from Purulha, Baja Verapaz, Guatemala; M. elegans, three males from Purulha, Baja Verapaz, Guatemala; and M. surinamensis, one male from Guyanas. All of the specimens studied are kept at the Museum of Zoology of the Universidad de Costa Rica. In M. elegans the diploid number is 30, with 16 macro and 14 microchromosomes and with an NF of

Immunological and histochemical identity of esterases and other antigens in elapid venoms.

Antibodies were prepared by hyperimmunizing rabbits with Naja naja, Bungarus fasciatus, Agkistrodon piscivorus and Apis mellifera (honeybee) venoms. By using immuno-electrophoresis, Ouchterlony technique and histochemical reactions, the identity of certain antigenic components and esterases in several elapid venoms has been demonstrated. There are a number of precipitin lines of identity for venom components in Naja species, while venoms of Bungarus , Dendroaspis , Micrurus , Bitis and Agkistrodon species gave mostly lines of non-identity or no precipitin lines with Naja naja antiserum. Further, it has been shown that several of the esterases present in Naja species are immunologically identical, while esterases from Dendroaspis, Micrurus, Bitis, Agkistrodon species and bee venom are not immunologically identical to those in the Naja species venoms.

Coral Snake Venoms

Abstract Cross neutralization and precipitin tests were performed with coral snake venoms and rabbit antisera against five venoms to determine the most suitable venoms for producing a polyvalent antivenin useful in treating persons bitten by coral snakes. Antisera were produced against Micrurus species M. fulvius, M. frontalis, M. spixii, M. carinicauda, and M. nigrocinctus venom but not against M. mipartitus venom. The latter was the only venom not neutralized by heterologous antisera. M. spixii venom was neutralized by all antisera. Anti-M. frontalis serum neutralized more heterologous (M. spixii) venom than homologous (M. frontalis) venom. The cross reactions suggest that some venom antigens that elicit precipitating and neutralizing antibodies may be distinct. M. frontalis venom produced the most cross-reactive neutralizing antibody, having neutralized five of six venoms. Of the venoms tested, M. frontalis venom would be most suitable for use in the production of a polyvalent coral snake antivenin.