Three major groups of eukaryotic organisms that cause disease in humans are:
Fungi, Protozoa & Helmiths
What are mycoses?
Mycoses are fungal infections & it is uncommon for healthy people.
What organism causes candidasis?
Dermatomycoses
What are dermatomycoses?
They are fungal infections on the skin. Causes by ringworms or tineas. Treated with Miconazole & clotrimazole, which blocks ergosterol synthesis. Ergosterol is essential for fungal cell membranes.
What does the fungi causing dermatomycoses feed on?
Feeds on keratin, which is the major structural protein of human skin. It requires the enzyme keratinase.
What is Stachybotris?
Wart like lesions of the hands legs and face
Why are fungi and other eukaryotic pathogens more difficult to treat than bacteria?
Because it's harder to find selectively toxic drugs for these diseases.
How do Miconazole & clotrimazole work as antifungal agents?
They block ergosterol synthesis which is essential for fungal cell membrane. It targets the fungi's cell membrane & it is selective because humans don't need ergosterol, we need cholesterol for our cell membrane.
What is Malaria caused by?
Plasmodium
How is Malaria transmitted?
It is transmitted by mosquitoes.
Plasmodium life cycle
infected mosquito carries plasmodium in salivary gland
bites human, plasmodium enters blood stream
migrate to liver, change form
multiply in liver, release to blood stream
invade RBC, feed on globin portion of hemoglobin inside RBC
multiply in RBC
Remaini
How long does it take Plasmodium to erupt from RBCs?
48 Hours
Where is Malaria an endemic?
Africa.
Why is Malaria rarely found in the US?
Because we don't have the specific mosquito that carried malaria (the Anopheles mosquito).
What is Giardiasis?
It is an intestinal parasite, transmitted through the fecal-oral route. Caused by Giardia intestinalis (protozoan)
How is Giardiasis transmitted?
It's transmitted through fecal oral routes. It attaches onto the intestinal wall. It is related to the signs and symptoms of the disease because once it is removed it leaves marks that can do permanent damage.
How is Giardiasis treated?
It is treated with Metronidazole (Flagyl) & it is selectively toxic because it will kill organisms that use anaerobic respiration.
What is Toxoplasmosis?
A fever producing illness cause by Toxoplasma gondii (protozoan). It is transmitted by cat feces and undercooked meat (usually beef).
Is Toxoplasmosis dangerous to everyone?
No it is not dangerous to everyone. It mostly affects rats.
Why is the chronic form of Toxoplasmosis dangerous?
It's dangerous when it is fetal infections because it can cause stillbirth or brain damage.
Why should pregnant women be careful?
They should be careful because if infected, it can transmit to the fetus and cause stillbirth or brain damage.
How does Toxoplasma affect rodents?
It affects the behavior of rodents to help itself get transmitted by invading the muscles and nervous system of the rat causing it to do the opoosite of what it would normally do in front of a cat.
What causes Ascariasis?
Nematodes
What is Ascaris?
It is transmitted through fecal oral routes. The eggs are shed in feces. The life cycle of this parasite is it goes to the intestines around the body to end up right back in the intestines where it reproduced and grows.
What is schistosomiasis caused by?
Schistosoma (a fluke)
Explain the life cycle of schistosomas.
The life cycle of schistosomas that cause the major symptoms are when eggs are embed in human tissue, this causes an immune reaction and the formation of granulomas.
Schistosomiasis
a disease that is caused by a parasitic blood fluke of the genus Schistosoma and that affects the skin, intestines, liver, vascular system, or other organs