Shigella dysenteriae

Shigellosis is endemic throughout the world and hyperendemic in developing countries. Shigella dysenteriae and Shigella flexneri are most common in developing countries.

Shigella dysenteriae is honored to the Japanese microbiologist, Kiyoshi Shiga, who isolated it from patients with dysentery during a particular severe epidemic in Japan.

The disease results from growth of Shigella spp. in the epithelial cells of the colon. Invaded cells die and the infection spreads to adjacent cells. The result is ulceration, inflammation and bleeding.

Complications may be seen in patients with Shigella dysenteriae Type 1 infections including, conjunctivitis, toxic neuritis, arthritis, haemolytic uraemic syndrome, seizures, sepsis and toxic megacolon.

Shigella dysenteriae are fatal and available in areas where public health facilities and sanitation are poor. Shigella dysenteriae Type 1 remains the most virulence of the shigellae. It is type principle species involved in major epidemics.

Shigella dysenteriae Type 1 is the only member of the various Shigella species that make Shiga toxin that has neurotoxic properties. This chromosomally encoded toxin homologous to Shiga toxin- producing E. coli. Patients infected with Shigella dysenteriae Type 1 are at risk of developing hemolytic uremic syndrome which carries a mortality rate of around 10%.
Shigella dysenteriae