Quiz 1 Pages 5 - 10 Flashcards
______ is when one partner benefits from the association, but the host is neither helped nor harmed.
Commensalism
Explain the difference between facultative and obligate parasites.
Obligate parasites cannot survive without a host but facultative parasites can.
Define definitive host and give the definitive host(s) for Leishmania donovani.
The definitive host is one on which the parasite reaches sexual maturity. For L. donovani, the definitive hosts are humans and dogs.
What are the 3 signs of infection in African Sleeping Sickness?
1) Chancre (at bite spot, infection and inflammation, painful and itchy, forms 1-3 weeks after bite and lasts 1-2 weeks, no scar)
2) Winterbottom Signs (enlargement of the glands in the posterior cervical region, starts about 1 month after infection and lasts for a few weeks)
3) Neurological complications (patients may be immobilized for their safety, they lose interest in things, coma, acute in 2-3 month, but chronic can take up to 2 years to get here)
What are 2 vector genus of Chaga’s disease?
Triatoma, Panstongylus, Rhodnius
How can you treat L. brasiliensis?
Long courses (30 days) of pentavalent antimonials in a high dose (ex: Stibium)
What is the treatment for parasitization by Hexamita meleagridis?
Oxytetracycline and proper flock management.
What is the danger of aggressive treatment of Plasmodium falciparum?
Healthy RBCs can be killed too and clog up all the organs.
Which parasitic protist if left untreated can lead to infertility?
Trichomonas vaginalis.
Giardiasis is caused by what parasite? What is the mode of infection?
Giardia lamblia. Person to person, water borne, venereal. Spread during periods of heavy rain.
What is an indirect parasite?
“Preying” on homeostatic mechanisms and reproductive efforts of organisms of lower trophic levels
The trypanosomes are a member of which phylum?
Euglenozoa
The trypanosomes are a member of which subphylum?
Kinetoplasta
What is a kinetoplast?
Disc shaped, DNA containing, organelle within the mitochondrion.
Where is the kinetoplast located?
Within the mitochondrion.
How do trypanosoma brucei reproduce?
By longitudinal binary fission.
Is Trypanosoma brucei an intracellular or extracellular parasite?
Extracellular.
Trypanosoma cruzi is responsible for which disease in humans?
Chaga’s disease (American trypanosomiasis).
Trypanosoma cruzi is endemic to which areas of the globe?
South and Central America.
L. donovani causes which form of leishmaniasis?
Visceral leishmaniasis (Kala-azar, dum dum fever, black disease)
L. tropica causes which form of leishmaniasis?
Cutaneous leishmaniasis (Delhi ulcer, oriental sore, Bagdad boil).
L. braziliensis causes which form of leishmaniasis?
Mucocutaneous leishmaniasis (espundia, Uta, chiclero ulcer)
Human contact with ___________ is necessary for infection by schistosomes
Water
What animal serves as a reservoir for S. Mekongi?
Dogs.
Explain the difference between mutualism, commensalism and parasitism
Mutualism = both benefit Commensalism = one benefits, one is neither helped nor harmed Parasitism = one benefits, one is harmed.
How is Trichomoniasis transmitted?
Sexual intercourse
What human disease is caused by Naegleria fowleri?
Primary amebic meningoencephalitis
What is the definitive structure of Apicomplexa? What are its three key parts?
The apical complex. Actually 4: polar ring, conoid, roptry, and micronemes.
What is the diagnostic stage of Plasmodium?
When the parasite is in the blood (as immature or mature trophozoite, or gametocytes)
What is the difference between uricotelicand ammonotelic organisms?
Uriotelic = excrete N as uric acid and its salts. Ammonotelic = excrete N as ammonia
Name 4 methods of reproduction that can be employed by protozoa.
Binary fission, sexual reproduction, budding, schizogony.
Name 2 general features of the Trypanosomatidae family.
Undulating membrane, heteroxenous, hemoflagellate.
What are three things Epidemiologists need to understand and why? (choose any 3 out of the 8 that we covered)
Local traditions, climate, sociological factors, global economics, pharmacology, pathology, biochemistry, clinical medicine
What is the difference between Epizootics and Zoonosis?
Epizootics = massive deaths of wild animals due to parasites Zoonosis = transmission of parasites from animals to humans
What are the two groups of parasite and what is the difference? What are the two types of parasites and what is the difference?
Obligate cannot survive without the host but facultative can.
Or endo and ectoparasite
Is this what they want??
What is a temporary parasite? And what is a temporary parasite also called?
Micropredator - drinks blood and transmits disease
What kind of parasite is Amoeba Naegleria fowleri (accidental, permanent, temporary, or parasitoids)? and what does it cause?
Accidental. PAM
What is the difference between female and male mosquitos?
Females drink blood (and transmit disease) and live longer, males only eat pollen.
List and explain the three types of hosts.
Definitive = is one on which the parasite reaches sexual maturity Intermediate = one that is required for parasite development but one in which the parasite does not reach sexual maturity Transport/Paratenic = in which parasite does not undergo any development, but remains alive and infective to another host
What is a reservoir host?
Animal that harbours an infection (parasite) that can be transmitted to humans
What is hyperparasitism?
Many parasites host other parasites
Explain the difference between direct tropic relationship and indirect trophic relationships?
Direct = parasites that eat the host Indirect = “preying” on homeostatic mechanisms and reproductive efforts of organisms of lower trophic levels
All parasites are heterotrophic, what does this mean?
They cannot manufacture their own food and need to get their energy sources from other organisms.
Explain infrapopulation, metapopulation and suprapopulation.
Infrapopulation = all parasites of a particular species occurring within the body of a single host individual Metapopulation = all the infrapopulations within a single host species in the ecosystem Suprapopulation = all the parasites of the single species, regardless of developmental stages, that occur in the ecosystem
What is multiple species infection?
Multiple species of parasites infecting one host.
There are four types of Parasite reproduction, list and explain all four.
Budding = new organism develops from an outgrowth or bud due to cell division at one particular site.
Binary fission = split into two (replication and cytokinesis)
Schizongy = nucleus replicates multiple times before actually splitting the cell (cytokinesis)
Sexual reproduction = fusion of gametes
Identify if the following characteristics of Protozoa are true or false and if false, please write the correct answer:
- Protozoa consists of a single cell: T or F
- All species contain only one nucleus during all portions of their life cycle: T or F
- Spores can only be built from one cell: T or F
Protozoa are eukaryotes: T or F
T
F - most of them contain more than one nucleus
F - can be built from more than one cell
T
List the eight characteristics of Protozoans’ nucleus and cytoplasm.
Plasma membrane, pellicle, glycocalyx, alveoli, pellicular microtubules, undulating membrane, Golgi apparatus, microbodies
What is the difference between Endoplasm and Ectoplasm?
Endoplasm = inside cell (sol layer, liquid) Ectoplasm = outside cell (gel layer, semi solid)
Explain the difference between encystment and excystation. What is the importance of cysts to parasites?
Encystment = forming cysts
Excystation = exiting cysts
Allows the parasite to survive in unfavourable conditions
What is the difference between pinocytosis and phagocytosis?
Pinocytosis is small intake (“cell drinking”)
Phagocytosis is taking in large things (“cell eating”)
Are Trypanosomatidae (Including genus Trypanosoma) heteroxenous or monoxenous? Explain what it means to be either or.
Heteroxenous. Means they have more than one host in their life cycle, monoxenous only have one host.
What are the three vectors of Trypanosoma cruzi (American sleeping sickness) and what is American sleeping sickness also known as?
Triatoma, Panstongylus, Rhodnius.
Chaga’s disease.
American sleeping sickness patients experience Ramana’s sign and megacolon, please explain what the two are.
Ramana’s sign = bite on face near eye that gets really swollen
Megacolon = parasite destroys nervous input to the colon and stops peristalsis. Gets enlarged since no food can get through.
Name the three species of Leishmania that are pathogenic for man, and explain the difference between the three.
L. donovani (visceral), L tropica (cutaneous), L brasilensis (mucocutaneous)
Where is Leishmaniasis prevalent worldwide?
South East Asia, Indo-Pakistan, Mediterranean, north and central Africa, South and Central America
What are the associated symptoms with being infected with Leismania donovani?
Fever 1-4 months after infection, enlarged liver and spleen, skin develops hyperpigmented granulomatous areas, susceptibility to infections, death if untreated.
What is the most common form of Leishmaniasis?
Cutaneous (L tropica)
What are the associated symptoms with being infected with Leismania tropica?
Papule forms 1-2 weeks after bite and grows to form a painless ulcer. Center of ulcer encrusts while satellite papules are produced at the periphery. Will heal in 2-10 months without treatment but will leave a scar.
What are the associated symptoms with being infected with Leismania braziliensis?
Initial symptoms are the same as cutaneuos, but then metastasizes to mucoid tissues and causes destructive lesions.
How is mucocutaneous leishmaniasis treated?
High doses of pentavalent antimonials (ex: Stibium) for long courses (30 days)
How does infection by Chilomastix mesnili occur?
Ingestion of cysts in contaminated water.
What drug is used to help treat galliform birds from Hexamita meleagridis?
Oxytetracycline
In what way is Trichomonas vaginalis diagnosed? And what is the treatment?
Wet mount of vaginal secretions, urine sediment, and prostatic massage.
Treat with Metronidazole.
What unites The Amoebas? What do Amoebas lack compared to the previous parasites we have mentioned? Do they have a cyst stage, a trophozoites stage, or both?
Pseudopodia.
No flagella or cilia.
Cysts and trophozoites.
What does Acanthomaeba spp. Cause?
Chronic infection of the skin or CNS
Why is it important for us not to disturb the parasites already on our skin?
We have an ecosystem living on and in our bodies. If we disrupt that then something will take its place - may be more harmful than what was there previously.
Entamoeba histolytica is the major cause of which Amoebiasis?
Amoebic Dysentery
What are the acute and chronic symptoms of amoebic dysentery?
Acute: frequent dysentery with necrotic mucosa and abdominal pain
Chronic: recurrent dysentery with blood and mucus in feces
What are the two medications used to treat amebic hepatitis, and how do they differ?
1) Iodoquinol (asymptomatic infections)
2) Metronidazole (symptomatic and chronic)
How are humans infected by Endolimax nana?
By ingesting cysts from food and water contaminated with cysts from host’s feces
What are the four Plasmodium species that are responsible for human malaria? Which is the worst?
P falciparum (the worst), P vivax, P ovalae, P malariae
Why do the medications that we are using for Malaria, not lasting very long?
Plasmodium changes its surface proteins very often so can become resistant very easily to our medications.
How does P. falciparum differ in morphology compared to other Malaria species?
Largest and banana shaped (gametes).
Why is difficult to diagnosis someone with Malaria based on the symptoms?
Because many other illnesses (like the flu and babesia microti) share very similar symptoms.
What are the two disease forms of Malaria? What are the key characteristics of each?
Complicated (cerebral malaria, pulmonary adema, severe anemia, cardiovascular shock, and abnormalities in blood coagulation) and Uncomplicated (last 6-10 hours every 2 to 3 days - cold stage, hot stage, sweating stage)
What are the two different treatment plans depending on what form of Malaria it is?
Treat with oral meds if it is uncomplicated malaria.
Treat with IV or intramuscular meds if it is complicated malaria.
What is the only member of the genus that infects man with Babesiosis?
Babesia microti
What is treatment plan for Babesiosis?
Clindamycin and quinine. Can recover spontaneously
What are the two phases of the lifecycle of Toxoplasma gondii? What is the primary host? And what are the intermediate hosts?
Sexual part (in cats)
Asexual part (any warm blooded animal)
Primary host is cats
Intermediate hosts are any warm blooded animal
Why is it very difficult to eradicate cysts of Toxoplasma gondii?
The cysts are inside the cells so the hosts immune system cannot detect them.
How can infection of Toxoplasma gondii in combination with first time pregnancy be harmful?
Can cross the placenta and cause hydroencephalus, intracranical calcification, or spontaneous abortion in the fetus.
