Enteroinvasive E. coli (EIEC)


E. coli (Escherichia coli) and Shigella are two types of bacteria that belong to the same family of Enterobacteriaceae. They are both gram-negative, rod-shaped, facultative anaerobes that can cause intestinal infections in humans and animals.

E. coli is a diverse group of bacteria that normally lives in the intestines of healthy people and animals. Most strains of E. coli are harmless or beneficial, but some can cause diarrhea, urinary tract infections, respiratory illness, bloodstream infections, and other diseases. E. coli strains are classified into different pathotypes based on their virulence factors and mechanisms of infection. Some of the most common pathotypes are enterotoxigenic E. coli (ETEC), enteropathogenic E. coli (EPEC), enterohemorrhagic E. coli (EHEC), enteroinvasive E. coli (EIEC), and enteroaggregative E. coli (EAEC).

Shigella is a group of bacteria that causes shigellosis, a severe form of dysentery characterized by bloody diarrhea, fever, abdominal cramps, and dehydration. Shigella is divided into four species: Shigella dysenteriae, Shigella flexneri, Shigella boydii, and Shigella sonnei. Each species has different serotypes based on the antigenic structure of its lipopolysaccharide (LPS) and other surface proteins. Shigella is highly infectious and can be transmitted by direct or indirect contact with fecal matter from infected people or animals.

E. coli and Shigella are closely related genetically and biochemically, but they have distinct epidemiological and clinical features. E. coli is more widespread and diverse than Shigella and can be found in various environmental sources such as water, soil, food, and animals. Shigella is more restricted to humans and primates and is mainly associated with poor sanitation and hygiene conditions. E. coli causes a range of intestinal and extraintestinal diseases depending on the pathotype, while Shigella causes a more severe and invasive form of dysentery that can lead to complications such as hemolytic uremic syndrome (HUS) and reactive arthritis. E. coli and Shigella can be differentiated by several biochemical tests such as lactose fermentation, motility, lysine decarboxylase activity, indole production, gas production from glucose, and urease activity. Additionally, molecular methods such as polymerase chain reaction (PCR), serotyping, multilocus sequence typing (MLST), and whole genome sequencing (WGS) can be used to identify and characterize E. coli and Shigella strains at the genetic level.

In summary, E. coli and Shigella are two related but distinct groups of bacteria that cause intestinal infections in humans and animals. They have different epidemiology, pathogenesis, clinical manifestations, diagnosis, and treatment options. Understanding their similarities and differences is important for preventing and controlling their spread and impact on public health.