Aspects of pathogenesis in a mouse model of infection by Corynebacterium pseudotuberculosis

A new medium, nutrient tween 80 broth (NTB) was utilised to achieve improved cultivation of Corynebacterium pseudotuberculosis. Twenty four hour NTB cultures were used for cutaneous and intraperitoneal infection of mice. The intraperitoneal administration of heterologous protein, liquid paraffin or thioglycollate prior to intraperitoneal challenge caused enhanced multiplication of the organism although this could be prevented by modifying host response. Pretreatment of skin with thioglycollate enabled cutaneous infection to be consistently achieved. The progress of lesions in skin and viscera is described. Immunisation of the mice was effected by both intraperitoneal and cutaneous routes of inoculation, the latter being particularly useful because it did not lead to residual lesions of viscera. Immunity was expressed by a failure of organisms to localise at secondary sites although infection of primary sites in skin or peritoneal cavity occurred, apparently at a reduced level. The relevance of these findings to the natural disease of sheep is discussed.