Parasites & Fungi Flashcards
Name three athropods
Sarcoptes scabiei, pediculus humanus, cimex lectularius
What causes the itchiness that is connected to athropods?
An allergic-like reaction that is produced by IgE, Th2-cells and mast cells, since they inject proteins that will stop blood from coagulating.
How does helmiths manipulate the immune system?
They can induce immunosuppressant cytokines, they do a lot of antigenic variation
Name some worms with direct life cycles
Ascaris lumbricoides, entrobious vermicularis, trichuris trichiura (whipworm)
Describe the general direct life cycle of a worm
Embryogenetic eggs are ingested by human, from contaminated food or water, and the worms hatch and mature and mate in intestines. Eggs come out with feces and can then spread.
Name some ways helmiths evade the immune system excluding antigenic variation?
They have different life stages, which involve different antigens. Moreover, they often move around in the body, and immune responses are often localized.
Name three diseases that are caused by protozoa
Giardiasis, Malaria, Trichomoniasis
Name one protozoa that has a direct life cycle
Giardia lamblia
Describe the general indirect life cycle of a protozoa
Indirect life cycle means that part of the life cycle takes place in a vector. Some protozoa such as Leishmania and trypanosoma reproduce here but are in another form than when in the human host. Then they are transferred to a human host, often through a bite of the vector, where they invade cells and the amastigotes multiply (asexual reproduction).
What are the two types of fungal forms?
Yeast and mold. Some fungi can switch between these forms and are called dimorphic fungi.
What is the Old Friend Hypothesis related to parasite infections?
The idea that the human immune system developed together with worms, and a lack of these parasites might lead to an increased tendency for allergies and autoimmune diseases.
What are “weep and sweep” reactions in the context of worm infections?
Immune responses involving increased gut mobility and mucus hypersecretion to flush out worms, and reduced villi to make it harder for worms to attach
How are flukes like Schistosoma transmitted to humans?
The parasites develop in snails, and then the head structure and tail are released into fresh water, where they can bind and penetrate human skin
What is a key feature of the Trypanosoma parasite essential for survival?
The flagellum, used for replication, food gathering, and movement. The flagellar pocket is important for recycling surface proteins
What are the main symptoms of Giardia lamblia infection?
Diarrhea. Often watery diarrhea
What is a major health concern associated with Cryptosporidium
It is a major cause of diarrhea in children, which can be deadly
What organ does the Plasmodium parasite initially infect in humans?
The liver
What causes the recurring fever associated with malaria?
Parasites bursting out of red blood cells and inducing cytokines.
Why is it harder to develop drugs against fungal infections compared to bacterial infections?
Because fungi are eukaryotes, similar to human cells, leading to potential side effects with antifungal drugs.
What are the five major groups of fungal diseases (mycoses)?
Superficial, Cutaneous, Subcutaneous, Systemic, and Opportunistic
How might climate change impact fungal infections?
It may allow fungi to grow at higher temperatures, potentially enabling them to better infect humans
