Di Genaro, M.S., Micalizzi, B. and Guzmán, A.M.S. de.
Area de Microbiología, Departamento de Bioquímica y Ciencias Biológicas. Facultad de Química, Bioquímica y Farmacia. Universidad Nacional de San Luis. Argentina.

Clostridium chauvoei is an anaerobic and sporulated bacterium which produces blackleg in cattle, sheep and other ungulates. Elsewhere we have studied the immunogenic power of the following antigenic preparations in mice: cellular extract(CE), a suspension of flagella (F), formolinized cells (FC) and heated cells (ØC), and the immunogenic power of the CE in guinea pigs. The aim of this work was to characterize these immunogenic preparations by SDS-PAGE and immunoblotting. When SDS-PAGE was carried out F showed 4 proteic bands, of 86,59,51 and 47 kD; CE showed 10 major bands of 86, 75, 62, 55, 47, 41, 30, 28, 25 and 16 kD; FC 6 major bands of 86,75,62,53,46 and 16 kD; and ØC 11 bands, the major ones have 80,41 and 16 kD. All the 3 preparations share the flagellar proteic band of 47 kD except the ØC. The formol-treatment reduces the number of the proteic bands when it is compared with those of the CE. The heat-treatment also reduces the number of the bands compared with CE´s and FC´s ones. When immunoblotting is analysed it can be seen that CE induces the antibodies that react with the 47 kD protein band, the same ones are induced by FC but no by ØC. On the other hand, CE induces antibodies that react with the 86 kD protein band, which is belived to be a polimeric form of flagelin monomer. According to these results and those obtained in the protection tests, we can conclude that: 1) Flagella are in part, responsable of the immunogenicity of the strain, 2) the buffer used to obtain the CE extracts flagellar and somatic antigens, 3) The formol-treatment reduces the proteic bands compared with CE, and retain their immunogenic power, 4) the heat-treatment reduces its immunogenic power which it is seen by its minor proteic bands number and by its lower immunoprotective power (results not shown here).