esides and replicates in the upper small intestine


Basically, you will listen to a 1-hour podcast and summarize the information from it. This is what my microbiology professor is expecting: “For part 1 of this assignment, you will listen to an episode from the podcast called “This Podcast Will Kill You” and then POST what you’ve learned to the class by replying to this discussion. In addition to describing your microbe and the disease it causes, you must include AT LEAST FIVE interesting facts about your podcast topic that are relevant to Microbiology.”

My microbe is Tuberculosis, and here is the podcast link:…

Pro tip: start after minute 5:30. Skip the intro.

Below is an example from one of the students in the class and how they answered to summarizing their podcast:

Giardia: Gerardia

Describe your microbe and the disease it causes:

Giardiasis is a disease that is caused by Giardia lamblia which is a protozoan parasite. This disease infects your intestines, causing the most known symptom, which would be having horrible diarrhea episodes. Other symptoms that you may have when dealing with this parasite would be generalize abdominal pain, nausea, and vomiting. Giardiasis is a common intestinal disease that spreads worldwide and are usually found in contaminated waters, streams, lakes, etc. Nearly 2% of adults and 6% – 8% of children in developed countries will be infected at some point in their lives with Giardia and nearly 33% of people living in developing countries will be infected at some point of their lives.

Giardia parasite was first founded/observed in 1681 by Anthony Von Leeuwenhoek, who was famous for his microscopes. Leeuwenhoek was able to observe Giardia by taking a sample of his own poop and examined it through a microscope. Fast forward to 1859, Vilem Dusan Lambl contributed to this Giardia finding by examining a stool of a child. In this stool it showed him a team of giardia protozoa which he then named it Cercomonas intestinalis and later it was renamed as Giardia lamblia.

Incubation Period for this disease would be around 1 – 3 weeks.

Giardia is a protozoan parasite which is a single celled organism that has four sets of flagella and two nuclei. This parasite has two morphologically distinct developmental forms. The first form is called the trophozoite and it resides and replicates in the upper small intestine and is responsible for disease manifestations. During the trophozoite phase, Giardia uses its four sets of flagella to swim through the intestine and uses the adhesive disk that is located on the opposite side of the flagella to stick on to the intestinal wall. While sticking around there, the parasite induces the epithelial cell layer of your intestine making your cells undergo apoptosis, which means the epithelial cells are killing itself. This causes an increase in the permeability of the epithelial cell layer. This parasite is also flattening your microvilli which are protrusion on your intestinal wall that increases surface area to be able to absorb water and nutrients. If the microvilli in your intestine is flattening it decreases that surface area so your intestine is not absorbing the water and nutrients that it needs which messes up your digestion and absorption. Since your intestine is not able to absorb the food that you eat, there is no nutrients causing malnutrition.

The second form is called the cyst, and it resides in the lower parts of the intestine. The cyst is the infectious part of the parasite because it is responsible for transmission. Once the cyst form leaves the host through the feces, it ends up in the environment which can transmit the Giardia parasite to another host. The cyst is very resistant to environmental stressors so it can survive in water like ponds, rivers, mountain stream for weeks to months. Once it hits the waters, any creatures or humans that takes a sip of that contaminated water would get a load of Giardia cysts going down their digestive system and the cysts would then split into two trophozoites and begin its cycle again.

The cause for diarrhea and malnutrition is due to Giardia increasing the rate of transit though the intestine. This causes food to move faster where the body is not able to absorb everything. More water is being pulled out from cells and bing brought into the intestine leaving you with watery stool.

As water treatments & filtration become more widespread in the first half of the 20th century Cases of intestinal disease declined in many places as well mortality for water born diseases. Risk of dying from water born disease is staggeringly high.

5 interesting facts related to microbiology:

1) Giardia is linked to later development of whole host of diseases that are usually considered as autoimmune disease like irritable bowel syndrome.

2) Due to the increase in intestinal wall permeability, the antigens from Giardia is being sucked into your bloodstreams, which causes the extra intestinal manifestation where it can cause eye infection, joint pain, and skin rashes.

3) It took about 200 years to get an official name and it took another 100 years to be recognize that it actually causes disease in humans. Basically, Giardia was recently acknowledged as a human pathogen roughly around 30 years ago.

4) Giardia is mainly considered as anthroponosis but it can also be a zoonotic transmission because it has serval distinct cycles that it circulates. There is the wildlife cycle where wildlife can infect other wildlife, livestock cycle where livestock on a farm can infect other livestock farm, domestic animal cycles where dogs and cats can infect each other, and human cycles.

5) There is a vaccine for dogs & cats but it did not work really well. This vaccine did decrease the shedding of cysts in the stool of dogs, but it doesn’t prevent or reduce symptoms of the disease. You can take antimicrobial medicines like Metronidazole or Nitazoxanide to help treat the Giardiasis disease.