Endotoxin Causes Damage to the Host

in this video we're going to begin our lesson on endo toxin and how endo toxin causes damage to the host. And so endo toxin is actually the specific molecule lipo Policy Sacha ride or L. P. S. For short. And so endo toxin or lipo Policy Sacha reid refer to the same exact specific molecule. And recall that this endo toxin or lipo Policy Sacha ride LPS is actually found in the outer membrane of gram negative cells. Now also recall that the lipo Policy Sacha ride or LPS contains the molecule lipid A. And so lipid A. Is actually going to be the toxic component of the L. P. S. That can actually trigger an inflammatory response and trigger other responses as well. And so lipid A. Can actually be released by these gram negative bacterial cells during bacterial cell multiplication or bacterial cell license. And so if we take a look at our image down below which will notice is over here on the left hand side we're showing you the gram negative cell wall and cell envelope and which will notice is that the gram negative cells have a very thin layer of peptidoglycan but surrounding their thin layer of peptidoglycan surrounding their thin cell wall. They have this outer membrane and in the outer membrane of gram negative cells is the endo toxin molecule. The lipo Policy Sacha ride or the L. P. S. And so if we zoom into this endo toxin or lipo Policy Sacha ride which will notice is that it has this O antigen region which is going to be a Policy Sacha ride. Then it has a core policy Sacha ride region which remains relatively consistent. The O antigen region tends to change across different strains of gram negative, different species of gram negative. And then at the very bottom which you'll see is this molecule here which is going to be the lipid a region of the endo toxin or of the lipo policy sacra and this region right here specifically the toxic component that can cause the damaging effects to the host. And so we'll get to talk a little bit more about endo toxin and its damaging effects as we move forward in our course. But for now this is our brief introduction to endo toxin and how it causes damage. And we'll be able to learn more as we move forward. So I'll see you all in our next video.

in this video, we're going to talk about how lipid A. Can cause septic shock. And so recalled from some of our previous lesson videos that lipid A. Is the toxic portion of endo toxin or lipo policy Sacha ride. And recall that the endo toxin or lipo palace aka ride, is found in the outer membrane of gram negative bacteria. Now if these gram negative bacteria are lISZT or ruptured then that could cause the release of the lipid A molecule. And so if lipid A is released. And if lipid A infects the bloodstream then it could initiate a culmination of systematic responses referred to as septic shock. And so septic shock can include things such as fever, anemia or low red blood cell count, weakness, diarrhea and inflammation and lipid A can also cause life threatening cytokine storms which again recall that a cytokine storm is just a massive release of cytokines or chemicals that are used for communication signals during um immune responses. And so by causing this uh cytokine storm, it could result in rapid dilation of the blood vessels or rapid enlargement of the blood vessels. And that can decrease blood pressure significantly. And so septic shock can actually have physiological effects on the heart, the vascular system and other body organs as well. And ultimately septic shock because it is once again life threatening, it could potentially lead to death. And so if we take a look at our image down below. Notice on the left hand side over here we're showing you a person that has lungs that are infected with some kind of gram negative bacteria. And so notice that if the gram negative bacteria are able to enter into the bloodstream, then when these gram negative bacteria are LISZT or when they rupture they could release lipid a into the bloodstream. And so if the infection enters into the bloodstream uh then it could potentially move to other organs as well. And so organs such as the brain, kidneys, liver and heart are all examples of organs that could be infected. And so this could lead to once again uh septic shock and again septic shock because it can have physiological effects on all of these different organs here. Uh in many cases patients are not able to recover and it could lead to death. And so um again this year concludes our brief lesson on how lipid a cause is septic shock and how that can be life threatening. And we'll be able to get some practice of applying these concepts as we move forward and be able to learn more as well. So I'll see you all in our next video

What part of lipopolysaccharide (LPS) is the dangerous portion of the endotoxin during bacterial infections?

• A. O-antigen.
• B. Lipid-A.
• C. Core Polysaccharide.
• D. The entire lipopolysaccharide molecule.

What type of bacteria create endotoxins?

• A. Gram-negative.
• B. Gram-positive.
• C. Both gram-negative & positive.
• D. Endotoxins are only produced by protozoa.

Lipid A is the toxic component of LPS. When pathogenic bacteria release Lipid A into the bloodstream the infected individual may experience septic shock. Lipid A represents _______.  

• A. A focal infection.
• B. An exotoxin.
• C. A systemic infection.
• D. An endotoxin.
• E. A and B.
• F. C and D.

An endotoxin:

• A. Is an AB toxin.
• B. Is created by gram-positive bacteria.
• C. Is heat stable and will not denature.
• D. Triggers T cells to release cytokines.