Escherichia coli is a gram-negative, rod-shaped, polymorphic bacterium, with non-pathogenic strains commonly found in the intestinal flora. It demonstrates stability in the environment, being able to survive in water, soil, and feces for long periods, sometimes many months. E. coli produces various enzymes that can break down polyhydric alcohols and carbohydrates such as glucose, galactose, and maltose, leading to the formation of pyruvates, which are then converted into acids such as acetic and formic acid. Despite extensive research on its biochemical properties, no direct relationship has been found between its enzymatic activity and pathogenic potential. Colibacillosis is an acute intestinal infection caused by specific serovars of E. coli and is usually transmitted by the fecal-oral route. This article reviews the morphological, staining, cultural, and biochemical characteristics of E. coli and its antigenic properties. Additionally, it covers the symptoms and diagnostic methods for colibacillosis caused by different strains of E. coli.
