In this video, we're going to begin our introduction to pathogenic toxins. Certain pathogens are capable of producing biological poisons called toxins, which allow the pathogens to invade and damage host tissues. The term toxicogenicity refers to the ability of the pathogen to produce toxins that damage the host cells. Toxins can be classified into two groups: the first group being the exotoxins and the second group being the endotoxins.

Exotoxins are soluble proteins released by a pathogen during an infection or following the lysis of the pathogen. As we move forward in our course, we will discuss exotoxins in more detail. We will also learn that there are three different categories of exotoxins, grouped by their structures and functions, which we will see in our image shortly. Endotoxins, on the other hand, specifically refer to lipopolysaccharide or LPS, found in the outer membrane of gram-negative bacteria.

We will talk more about endotoxins as we continue. For now, this is just the introduction. In our image below, you'll notice a map of our lesson on pathogenic toxins. These toxins can be categorized either as exotoxins or as an endotoxin. The exotoxins can be further categorized into three groups: the AB toxins, the membrane damaging toxins, which include pore-forming toxins and phospholipases, and the superantigens.

As we progress, we will discuss each of these groups of exotoxins in more detail. Endotoxin specifically refers to the lipopolysaccharide or the LPS found in the outer membrane of gram-negative bacteria. It is also important to note that the host immune system is capable of causing unintended damage to host cells when it is overstimulated during an infection. Sometimes pathogens can harm simply by inducing our own host immune system to overstimulate and cause damage.

This concludes our brief introduction to pathogenic toxins, and we will learn more about them as we move forward in our course. I'll see you all in our next video.