Detoxified immunogenic derivative of clostridium perfringens b-toxin or an immunogenic fragment thereof, nucleotide sequence comprising a mutant DNA fragment, clostriduim perfringensm expression system based on a gram-positive bacterium, vaccine to combat clostridium perfrigens infection, process for the preparation of native b-toxin from clostridium perfrigens, and, process for preparing a vaccine to combat infection of clostridium perfrigens.

摘要

"DETOXIFIED IMMUNOGENIC DERIVATIVE OF 225 -TOXIN FROM CLOSTRIDIUM PERFRINGENS OR ITS IMMUNOGENIC FRAGMENT, NUCLEOTIDE SEQUENCE UNDERSTANDING A MUTANT DNA FRAGMENT, CLOSTRIDIUM EMPHASIS, EMPHASIS OF EMPHASIS, EMPHASIS OF EMPHASIS PERFRINGENS, PROCESS FOR THE PREPARATION 225 - NATIVE TOXIN OF CLOSTRIDIUM PERFRINGENS, AND, PROCESS FOR THE PREPARATION OF A VACCINE TO COMBAT INFECTION OF CLOSTRIDIUM PERFRINGENS ". The present invention relates to the detoxified immunogenic derivatives of Clostridium perfringens 225 -toxinaf or an immunogenic fragment thereof that has the characteristics that they bring about a mutation in the amino acid sequence of 225 -toxin, not found in the sequence of amino acids of the wild type 225 toxin. The invention also relates to the genes encoding such β-toxins, as well as the expression systems that express such β-toxins. Furthermore, the invention relates to bacterial expression systems that express a native β-toxin. Finally, the invention relates to vaccines based on detoxified immunogenic derivatives of Cloristridium perfringens toxin, and to the processes for preparing such vaccines.