THE COMPARATIVE HISTOPATHOLOGY OF PRIMARY AND SECONDARY LESIONS IN MURINE SALMONELLOSIS

  • 1 January 1980
    • journal article
    • research article
    • Vol. 61  (1) , 76-84
Abstract
In a primary infection, Swiss-Webster mice were injected i.p. with 102 or 103 virulent Salmonella typhimurium. Multiple microscopic acute abscesses with predominantly polymorphonuclear leukocytes (PMN) were seen in the liver and the spleen beginning on the 4th day after infection. By the 7th day, these lesions became enlarged and were gradually transformed into granulomas with central necrosis and peripheral mononuclear cells. The animals usually died within 12 days with massive systemic infection and degeneration of the tissues. It was necessary to inoculate 106 virulent salmonellae i.v. into mice immunized with avirulent S. typhimurium to initiate microscopically observable lesions in the liver and the spleen. These secondary lesions were characterized by the early appearance of minute granulomas composed almost entirely of histiocytic cells. They remained small and isolated, usually without central necrosis. Subsequent regression of the lesions and regeneration of normal tissue occurred after the 2nd wk following infection. The animals usually surivived such a challenge infection.