Shigella dysenteriae

Shigella dysenteriae is a species of Gram-negative bacteria in the genus Shigella, which is responsible for causing dysentery. This bacterium is rod-shaped, non-motile, and does not form spores. It is a facultative anaerobe, meaning it can survive in both oxygen-rich and oxygen-poor environments.

Characteristics

Shigella dysenteriae is unique among the Shigella species due to its ability to produce Shiga toxin, a potent neurotoxin that can cause severe damage to the lining of the intestines and other tissues. This toxin is responsible for the severe symptoms associated with dysentery, including bloody diarrhea, abdominal pain, and fever.

Pathogenesis

Shigella dysenteriae is transmitted via the fecal-oral route, often through contaminated food or water. Once ingested, the bacteria invade the cells of the intestinal lining, causing inflammation and tissue damage. The bacteria can also spread to other parts of the body, causing systemic infection.

Treatment and Prevention

Treatment for Shigella dysenteriae infection typically involves rehydration and antibiotic therapy. However, some strains of the bacteria have developed resistance to common antibiotics, making treatment more difficult. Prevention of infection involves proper sanitation and hygiene practices, including handwashing and safe food handling.

Epidemiology

Shigella dysenteriae is most common in developing countries with poor sanitation and hygiene practices. Outbreaks often occur in crowded conditions, such as refugee camps or urban slums. However, the bacteria can also cause sporadic cases of dysentery in developed countries.

See Also

• Shigella sonnei
• Shigella flexneri
• Shigella boydii

• Dark field microscopy revealing Shigella dysenteriae bacteria
  Dark field microscopy revealing Shigella dysenteriae bacteria