Shigella Research Paper

Consumption of food is vital for maintaining a person’s life and growth. Consumption of safer food is even more vital. Every day, humans are at a risk of falling ill due to potential pathogens lurking either in the environment or in their food. Foodborne illnesses due to these very pathogens has increased the global burden of disease. Thus, it is critical that disease trends, causes and risk factors be identified to reduce the spread of illness across the world. This report gives a detailed look at the science of epidemiology, the types of studies performed to collect and inspect disease-related data, and some important terminology to better understand the same. This report also focuses on foodborne illness causing pathogen Shigella, its characteristics

They are short and about 0.5 x 1.3 m in size and may be classified as facultative anaerobes. Their optimum growth pH and temperature is 7.4 and 37 respectively, while growth also occurs between 10-40. When plated on SPC, they form circular, convex, and translucent colonies with a diameter of 2 mm. DCA and XLD are often used as selective media to grow Shigella colonies. Generally, Shigellae are not very resistant; they can remain viable in moist environments, but die quickly on drying. Temperatures as high as 56 can easily kill them within an hour, while acidity produced by coliform in feces also result in their death. Among Shigella species, S.sonnei shows more resistance (Paniker,

Once ingested, it is believed that Shigellae pass the GI tract to reach the colon and rectal epithelium and then use Microfold cells to infect macrophages. The M cells carry the Shigella cells to the lymphoid tissue which initiates an immune response. A strong inflammatory reaction occurs in the intestine along with the appearance of Shigellosis symptoms (Faruque, 2012).
The main clinical features are watery loose stools, abdominal pain, bloody diarrhea, tenesmus, and fever depending on the severity of the disease. In rare cases, complications may occur and include toxic neuritis, bacteremia, seizures in young children, and hemolytic-uremic syndrome (Iwamoto et al., 2010). Usually, Shigellosis has a short incubation period (1-3 days), but severe infection may require hospitalization especially in malnourished children, elderly people and immunocompromised people. Some people may also be asymptomatic (Faruque,