The Natural Resistance to Salmonella Typhimurium of the Normal Mouse, Rat and Pyridoxine-Deficient Rat

Abstract

Summary The interaction of Salmonella typhimurium and the humoral and cellular defenses of normal rats and mice and pyridoxine deficient rats has been compared. These strains are killed by rat serum but not by mouse serum. Normal rats and mice rapidly clear the majority of the bacteria from the blood stream but a residual bacteremia is always found in the mouse. These virulent organisms multiply within the cells of the reticuloendothelial system of both the rat and mouse. The total number of organisms in the liver and spleen of the mouse shows a consistent upward trend accompanied by bacteremia. The number of organisms in the liver and spleen of the rat follows a cyclical rise and fall. A concomitant bacteremia has been demonstrated when the cycles are at their peak. It is suggested that the fall in numbers is due to the bactericidal action of serum upon bacteria escaping from the RES. Pyridoxine deficiency in the rat does not alter the bactericidal power of the serum or the ability of the cells of the RES to control this pathogen.