Studies on experimental shigellosis. II. The effect of fasting and fatigue on Shigella flexneri 3 infections in mice.

Host resistance to Shigella infections can be decreased by non-specific physical stress. Fasting lowers the number of Shigella required for a parenteral LD(50) dose. While the LD(50) by the oral route is larger in fasted than in nonfasted animals, the fasted host's susceptibility to oral infection is increased as evidenced by the increased fecal Shigella carrier state, duration of intestinal infection, and increased incidence of Shigella bacteriemia. Fatigue also increases the animal's susceptibility to shigellosis, but to a lesser extent than does fasting.