Which type of bacteria typically have an endotoxin in their cell wall?

The presence of endotoxins in the cell wall is a characteristic feature of Gram-negative bacteria. Endotoxins are components of the outer membrane of the cell wall of these bacteria, specifically lipopolysaccharides (LPS), which can trigger a strong immune response in the host. When Gram-negative bacteria are lysed or die, they release these endotoxins into the surrounding environment, which can lead to systemic inflammatory responses and symptoms such as fever, shock, and other effects associated with infections.

Conversely, Gram-positive bacteria lack an outer membrane and therefore do not possess endotoxins in their cell walls. Gram-positive bacteria typically have a thick peptidoglycan layer, which can have other types of toxins, but these are distinct from the endotoxins found in Gram-negative bacteria. Other categories such as aerobic or facultative anaerobic bacteria refer to metabolic characteristics rather than structural features like the presence of endotoxins. Thus, the correct identification of Gram-negative bacteria as the source of endotoxins is fundamentally linked to the specific composition and structure of their cell wall.