INCREASING THE IMMUNIZING VALUE OF A Clostridium septicum STRAIN

Abstract

The pathology caused by bacteria belonging to the genus Clostridium is a major cause of economic loss in small ruminant herds. The clinical manifestations caused by these pathogens are the result of a wide and variable spectrum of toxins released during their multiplication. The aim of this study was to enhance the toxigenesis of one of the Clostridium septicum isolates and to select the most productive clone, being the closest to the field strain. The strain toxicity was improved by passages on guinea pigs. In vivo assays on balb/C mice were confirmed by in vitro experiments (Western Blott, semi quantitative dosing of cytopathic effect and quantification of hemolytic activity). Assessment of the immunizing value was carried out by seroneutralization in mice. The selected and improved strain produced a toxin with a biological value superior to the minimum recommended limits for the formulation of anaerobic vaccines for small ruminants.