 Welcome back everybody. Today we are going to discuss some microbiology. Specifically, we will talk about protozoa. The first protozoa we will discuss is Giardia lambia. Giardia lambia causes a disease known as Giardiasis. The transmission route for Giardiasis is through a fecal oral route. As you can see on this diagram to the right, we will start at the top where the a human ingests the dormant cysts. They undergo excistation, which is removing it from the cyst form into a trophozoite form. That is where these organisms undergo asexual replication and then as the organism moves towards the colon to where it will be expelled from the body, it re-insists itself, or incestation, and then is expelled from the body via the feces. The only way that a Giardia lambia organism can survive outside of the body is in the cyst form. And in that cyst form, as you see here, it can survive for quite a long time in cold water. This is how we receive that fecal oral route back into the human body where it can then undergo more replication and more transmittance. Symptoms of a Giardia lambia infection include fatty, foul-smelling diarrhea. To diagnose this, we take a stool sample and you will see multi-nucleated trophozoites or cysts. As you can see over on the right, the trophozoites have the multi-nucleated cells and then your cysts will have upwards of four nucleus. You can think the transmission of this is often seen in daycares as well as camping grounds, people outside and ingesting contaminated water. The malabsorption causing this fatty smell, foul-smelling diarrhea is going to be specifically located in the duodenum and the ginginum. To treat this, we treat with metronitazole. Remember our mnemonic for metronitazole is GIT GAP. One of those G's is for Giardia lambia. Next, we will talk about amibiosis. This is due to intameba histolitica. Once again, our transmission is a fecal oral route and this comes specifically through contaminated water or food. The symptoms of an intameba histolitica infection include bloody diarrhea, which is different from our fatty foul-smelling diarrhea of Giardiasis. You can also see liver abscesses and because of that liver infection, that is how we can get right upper quadrant pain. To diagnose this infection, we specifically use serology in an antigen testing or you can also do a stool test and look for trophozoites in the stool. As you can see here, this is a trophozoite in the stool from someone infected by intameba histolitica. We treat this with metronitazole once again. Remember our mnemonic we just talked about, GIT GAP. Intameba histolitica is the E in GIT GAP. Next, we will talk about cryptosporidosis. Cryptosporidosis is caused by multiple cryptosporidium species. It is transmitted once again through the fecal oral route. Our symptoms include a mild watery diarrhea, so you can distinguish between the different types of GI protozoa based upon their diarrhea. Our Giardiasis is a fatty foul-smelling diarrhea. Our amabiasis is a bloody diarrhea and our cryptosporidium is a mild watery diarrhea. You will see on a acid-fast stain oocytes that are in the stool. So we do a stool sample to diagnose and we see those oocytes as you can see here. To be able to remove this contamination from water, we can boil the water and of note, this is the most common cause of diarrhea in AIDS patients. Treatment is usually supportive. Typically, we will give fluid rehydration and electrolyte replacement, such as sodium, potassium, bicarbonate and glucose. We can also use some anti-motility agents such as low-paramide. This is typically only lasting about two weeks and will go away on its own without any medication.