Invasion and the Pathogenesis of Shigella Infections

Bacillary dysentery, or shigellosis, is caused by penetration of Shigella spp into the intestinal mucosa of the colon, where degeneration of the epithelium and a strong inflammatory reaction indicate sites of infection (LABREC et al. 1964). Clinical signs of shigellosis range from mild diarrhea to severe dysentery with blood, mucus, and pus in the stool. Epidemiological studies indicate that SHIGELLA are transmitted by the fecal-oral route and sometimes by contaminated food (WHARTON et al. 1990). Shigella are highly infectious organisms for human beings, since only a few hundred bacteria administrated orally caused disease in 50% of volunteers (DUPONT et al. 1989).