Microbiology Practice Exam 2026 – Comprehensive All-in-One Guide for Exam Success!

Endotoxins are primarily associated with Gram-negative bacteria. These are components of the outer membrane of the cell wall of these bacteria and consist mainly of lipopolysaccharides (LPS). When Gram-negative bacteria die or undergo cell lysis, endotoxins are released into the surrounding environment, which can trigger strong immune responses in the host. This can lead to symptoms such as fever, inflammation, and in severe cases, septic shock.

The structure of Gram-negative bacteria is crucial for the presence of endotoxins. The outer membrane is unique to these types of bacteria, distinguishing them from Gram-positive bacteria, which do not possess this outer membrane and therefore do not release endotoxins in the same manner.

Fungi and viruses do not produce endotoxins; fungi have different cell wall compositions and viruses lack a cell wall entirely. Understanding the association of endotoxins with Gram-negative bacteria is fundamental in microbiology, especially in clinical settings, where infections caused by these bacteria can lead to significant health issues due to the effects of endotoxins on the immune system.