Figure 2.

Intestinal (A) and gas gangrene (B) schematic models of infection with toxigenic bacteria. (A) Toxigenic bacteria grow and produce toxins either in food, intestinal lumen, or on the intestinal mucosa surface. Entero-invasive bacteria inject virulence factors (VF) into intestinal cells, which mediate their cell entry. (B) Toxigenic bacteria enter into the organism through tegument breaking. The presence of necrotic tissues facilitates initial bacterial growth and production of toxin(s), which diffuse locally leading to additional tissue necrosis and subsequent bacterial growth and toxin synthesis. In addition, toxins impair host defenses via inhibition of leucocyte/macrophage migration and inhibition of phagocytosis. Passage of sufficient amounts of toxins into the blood circulation leads to toxic shock.