What virulence factor is associated with some strains of E. coli that cause severe intestinal disease?

What virulence factor is associated with some strains of E. coli that cause severe intestinal disease?

• A. Capsular polysaccharides
• B. Shiga toxin
• C. Lipopolysaccharides
• D. Endotoxin

Answer: (B)

The association of Shiga toxin with certain strains of E. coli, such as Enterohemorrhagic E. coli (EHEC), is critical for understanding the severe intestinal disease these bacteria can cause. Shiga toxin is a potent cytotoxin that inhibits protein synthesis in host cells, leading to cell death and contributing to the severe effects observed in infections, including bloody diarrhea and hemolytic uremic syndrome (HUS). This toxin disrupts the intestinal lining, resulting in inflammation and ulceration. The presence of Shiga toxin is a significant factor that differentiates pathogenic E. coli strains from non-pathogenic ones, further emphasizing its role in the virulence and pathogenicity of the organism in gastrointestinal diseases. The ability of this toxin to enter the bloodstream and cause systemic effects also underlines its importance as a virulence factor. In comparison, while capsular polysaccharides, lipopolysaccharides, and endotoxins are related to the structural components and general pathogenicity of bacteria, they do not specifically account for the same severity and mechanism of action as Shiga toxin in causing dire intestinal disease.

The association of Shiga toxin with certain strains of E. coli, such as Enterohemorrhagic E. coli (EHEC), is critical for understanding the severe intestinal disease these bacteria can cause. Shiga toxin is a potent cytotoxin that inhibits protein synthesis in host cells, leading to cell death and contributing to the severe effects observed in infections, including bloody diarrhea and hemolytic uremic syndrome (HUS).

This toxin disrupts the intestinal lining, resulting in inflammation and ulceration. The presence of Shiga toxin is a significant factor that differentiates pathogenic E. coli strains from non-pathogenic ones, further emphasizing its role in the virulence and pathogenicity of the organism in gastrointestinal diseases. The ability of this toxin to enter the bloodstream and cause systemic effects also underlines its importance as a virulence factor.

In comparison, while capsular polysaccharides, lipopolysaccharides, and endotoxins are related to the structural components and general pathogenicity of bacteria, they do not specifically account for the same severity and mechanism of action as Shiga toxin in causing dire intestinal disease.