Bacterial Virulence Factors

Virulence factor

A structure, product, or characteristic that helps a microorganism cause disease.

Capsule as a virulence factor

Helps bacteria avoid phagocytosis and can help with attachment.

Adhesins

Structures or molecules that allow bacteria to attach to host cells.

Fimbriae as a virulence factor

Help bacteria attach to host cells and surfaces.

Flagella as a virulence factor

Allow bacteria to move toward favorable environments.

Exotoxins

Toxins secreted by bacteria that damage host cells or disrupt host functions.

Endotoxin

The toxic portion of LPS associated with Gram-negative bacteria that can trigger inflammation and fever.

Bacterial enzymes as virulence factors

Can help bacteria invade tissues, obtain nutrients, or evade host defenses.

Biofilm

A community of microorganisms attached to a surface and surrounded by a protective matrix.