microbe use to cause damage to host cells

Answer 1

Microbes use all of the above to cause damage ti the host cells. Each micro organism has special characteristic that help them invade the host tissue and cause disease.

I will explain each of the factors along with an example of how the bacteria uses it for pathogenesis:

1.) LPS-Lipo Poly Saccharide: This is the outer cell wall of Gram Negative bacteria like E. coli, Enterobacter, Pseudomonas, etc, that spreads in the blood and causes sepsis. Once the bacteria is engulfed by the innate immunity of our body, the macrophages and engulfs and phagocytoses the bacteria followed by lysis due to the lysosomal enzyme degradation.

Once, the bacteria are lysed, the fragments of bacteria including the outer cell wall (ie. LPS) circulates in the blood and causes fever, shivering and sepsis which is a dangerous situation and needs to be treated soon.

2.) Capsule and slimy layer-Some bacteria like Klebsiella, Neisseria meningitidis have a capsule around them and the capsule prevents the phagocytosis of bacteria by the macrophages. Thus the bacteria are easily able to invade the body.

3.) The fimbriae and pili of bacteria, besides helping in motion of the bacteria within the body, also helps to attach the bacteria to certain receptors on cell surfaces and enter them.

4.) Some bacteria like Streptococcus pyogenes, beta hemolytic Streptococci produce destructive enzymes like hemolysins that can break red blood cells. Staphylococcus aureus produces enzymes like proteases and lipases that break the host protein and tissue. Some bacteria produce hyaluronidases that cleave the connective tissue of the body.

5.) Endotoxins are the same as LPS I have referred to Point number 1. LPS or Lipo Poly Saccharide is the outer cell wall of all Gram negative bacteria that once are fragmented circulate in the blood and causes inflammation. And, if the infection proceeds further, can cause endotoxic shock.

6.) Exotoxins are the toxins secreted out (exo) by bacteria which affect the biochemical pathways of cells. They include exotoxin produced by Clostridium tetanus which causes tetanus. The exotoxin of Vibrio Cholera causes cholera. The exotoxin of Bacillus anthracis causes anthrax.

Besides these, there are a few other virulence factors in bacteria, viruses and fungi that are specific to each type of microbe.

Answer 2

If asked which of the following choices BEST suits the case of what a microbe could use to cause harm to a host, I would say the Actions of the Toxin. An example of this is the extremely deadly botulism toxin derived from Clostridium Botulinum.At extremely low concentrations ( something like a pin head in size) could kill upwards of 1 million people!!!

However, the question simply asks which of the following can be used by a microbe to cause damage to the host cell and that would technically mean that both the actions of toxin AND the action of the enzymes (endoenzymes and exoenzymes) can cause damage to the host cell. This being the case as the toxin could harm the host in the same way that the enzymes used by the microbe could help the microbe avoid host detection and break down tissue of the host without being noticed by the immune system!

It is likely that the teacher wants one to chose the actions of the toxins if can only pick one, but ask what is this question asking and how should I respond to avoid losing credit!