COMPARATIVE HISTOPATHOLOGY IN MOUSE TYPHOID AMONG GENETICALLY DIVERSEMICE

Genetically resistant CBA and A/J mice and susceptible BALB/c and C57B L6 mice were challenged with either an identical infective dose or a m inimal lethal dose of Salmonella typhimurium. The histopathological pr ogression of the disease was examined in tissue sections prepared by t he JB-4 Plus resin embedding method and compared between the resistant and susceptible mice. In a fatal disease, the lesions in both animal hosts began with focal abscesses within the first three days post infe ction. Mononuclear cell infiltration started by day 4 and transformed the lesions into granulomata. Well-formed granulomata were evident by day 7 and persisted in sublethally infected resistant mice. Massive ba cterial proliferation and extensive tissue degeneration marked the ter minal stage of a lethal challenge. There were no distinguishable featu res that would identify the tissue response to infection in a resistan t host from a susceptible one, except that the lesions in the subletha lly infected resistant mice advanced slower and were discrete and self -limiting.