Abstract
Tyzzer's disease in euthymic mice was aggravated by splenectomy, treatment with carrageenan, India ink or silica. The aggravating effect was more prominent when splenectomy was performed 3 days rather than 7 days before infection. Blocking of the reticuloendothelial system was most effective in increasing the severity of infection when made on the day following the inoculation. Non-treated athymic nude mice did not show enhancement of the infection compared with euthymic mice. In nude mice splenectomy done 6 days before infection combined with carrageenan treatment on 1 day p.i . showed hepatic lesions as severe as seen in cortisone-treated euthymic mice.
