Immunogen and antivenom against violin spider venom

The invention relates to the isolation, characterization and expression of DNA fragments encoding sphingomyelinases D from three species of Loxosceles genus spiders, namely L. boneti, L reclusa and L. laeta, and the toxoids thereof. The invention also relates to the production of active sphingomyelinases D and the toxoids thereof using recombinant means and to the use of same as an immunogen for the production in vertebrates of antibodies that neutralise the corresponding venom and the respective fragments F(ab′)2. The invention further relates to the use of recombinant sphingomyelinases D as part of an antigen matrix which can be used in the immunopurification of antibodies and the fragments thereof or as part of any diagnostic device used to obtain clinical confirmation that the causal agent of poisoning in a patient is a spider of the Loxosceles genus. In addition, the invention includes molecular vectors for the expression of the DNA fragments, strains comprising same, which can express Loxosceles sphingomyelinases D, and methods for the expression thereof. AA Porcentaje de identidad de aminoacidos entre necrotoxinas de diferentes especies de Loxosceles. especie BB Lb1 Lr1 Lr2 La Li Ll-H17 Ll-H13 Ll-1 Ll-2 Lb1 - Lr1 91 - Lr2 84 90 - La 86 88 87 - Li 82 84 88 80 - Ll-H17 57 60 60 59 59 - Ll-H13 57 60 61 58 60 80 - Ll-1 56 59 59 58 59 99 80 - Ll-2 57 60 61 59 59 82 94 82 - AA . . . AMINO ACID PERCENTAGE OF IDENTITY BETWEEN NECROTOXINS OF DIFFERENT LOXOSCELES SPECIES BB . . . SPECIES