Shigella sonnei is a type of bacteria. It is a gram negative organism and is facultatively anaerobic, meaning that it can live with or without oxygen. It is a rod-shaped type of bacteria. The Shigella bacteria is a non-motile organism. Many microorganisms have flagella which are long tales that power the organism through its environment. This function helps the organism to seek out nutrients as well as move away from anything that could damage the bacteria.
The Shigella organism is best known for causing dysentery. Interestingly enough, this microorganism does not do well in many environments. It cannot survive in nature, as it requires a low pH to function and also prefers a slightly warmer environment. In a laboratory setting, scientists trying to experiment with the bacteria have to be extremely careful because it is such a fragile organism.
Due to the optimal pH and temperature, the human body is the best place for the Shigella sonnei to live. Specifically, the gastrointestinal tract has the optimal pH needed for growth. Also, the temperature of the human body is what the organism prefers, making the human body the most common host. The Shigella organism is usually spread through the fecal-oral route and is especially dangerous in countries without sanitary drinking water. Human waste can leak into the water supply and spread the disease to many people. Also, those who have the bacteria in their system and are not careful to practice proper hygiene habits can easily spread the bacteria without meaning to.
When in the intestinal tract, the Shigella bacteria causes gastrointestinal problems, also known as shigellosis. The bacteria can excrete a toxin that will cause inflammation in the intestines and kill the cells in the epithelium of the colon walls. The death of these cells causes even more inflammation and sometimes will cause bleeding into the colon.
The disease caused by Shigella sonnei is dysentery, which means fecal matter with pus and blood. Due to the damage that the toxin does to the digestive tract, patients often experience diarrhea with blood, an especially dangerous symptom.