Term
| types of asexual reproduction |
|
Definition
-budding (Ephelota)
-fission (Euglena)
-schizogony (Plasmodium) |
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Term
|
Definition
| nucleus undergoes multiple divisions before cell divides |
|
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Term
|
Definition
-unicellular, eukaryotic, chemoheterotrophic
-variety of shapes and sizes
-200,000+ named species (10k parasites) |
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Term
|
Definition
-organism that obtains food and shelter from host and derives all benefits from the relationship
-vector is an organism that transmits parasite |
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Term
| types of sexual reproduction |
|
Definition
|
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Term
|
Definition
-exchange of nucleus from one cell to another followed by fusion of nuclei and recombination
-Paramecium |
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Term
|
Definition
-two haploid gametes fuse to form a diploid zygote
-Plasmodium |
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Term
|
Definition
-allows parasite to survive outside host
-Important for parasites who have to be excreted from
-Giardia
one host to get to another host |
|
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Term
|
Definition
-active form
-proliferate in tissues and cause damage |
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Term
|
Definition
-asexual reproduction of parasite
-Tsetse fly |
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Term
|
Definition
-sexual reproduction of parasite
-Quagmire |
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Term
| Entamoeba histolytica (Amoebae) |
|
Definition
-major cause of amebic dysentery
-0.5 to 50% of the population world wide
harbors E. histolytica parasites with the
higher rates of infection being in underdeveloped countries
-1-3% of US is infected
-humans are principal host (dogs cats can be too)
-no intermediate host |
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Term
| roles of vector in transmitting disease |
|
Definition
-mechanical transport of parasites
-act as intermediate host(Taxoplasma in mammals)
-act as definite host (plasmodium in mosquito) |
|
|
Term
|
Definition
-Ameboid appearance, usually 15-30 μm
in diameter
-Has a single nucleus with a distinctive small central
karyosome (mass of DNA) |
|
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Term
| infection by vector borne diseases occurs by |
|
Definition
| ingestion of cysts on fecally contaminated food or hands |
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Term
|
Definition
-P. falciparum, P. vivax, P. ovale, and P. malariae responsible for malaria
-200 million global cases
-kills more than one million people per yr
-P. falciparum and P. malariae are the most common species of malarial parasite and
are found in Asia and Africa |
|
|
Term
|
Definition
-acute: freq. dysentery, necrotic mucosa, abdominal pain
-chronic: recurrent episodes of dysentary with blood/mucus in feces, cysts found in stool
-may invade the liver, lung and brain where it produces
abscesses that result in liver dysfunction, pneumonitis, and encephalitis |
|
|
Term
|
Definition
-Asymptomatic infections treated with
Iodoquinol (unknown mechanism)
-Symptomatic and chronic amebiasis is treated with metronidazole
(inhibit nucleic acid synthesis) |
|
|
Term
| morphology of malaria parasite trophozoites |
|
Definition
-ring shaped
-1-2 microns (sexual forms are much larger) |
|
|
Term
| overall life cycle of malaria |
|
Definition
Transmitted by the infected female anopheline mosquito
which injects sporozoites present in the saliva of the insect |
|
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Term
|
Definition
-Quinine derivatives interfere with the parasite's ability to break down and
digest hemoglobin, thus starving the parasite and/or causing the build-up of
toxic levels of partially degraded hemoglobin in it
-Drug resistance, particularly in P. falciparum and to some extent in P. vivax is a major problem
-eradication of infected anopheline mosquitos
-Vaccines are being developed and tried but none are available yet for routine
use |
|
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Term
|
Definition
-headache, lassitude, vague pains in bones and joints, chills and fever
-As the disease progresses, the chills and fever become more prominent. The chill and fever follow a cyclic pattern (paroxysm) with the symptomatic period lasting 8-12 hours. In between the symptomatic periods, there is a period of relative normalcy
-At the end of this period, the body temperature begins to climb and reaches 103-106 degrees F
-Fever is associated with severe headache, nausea (vomiting) and convulsions
-Each paroxysm is due to the rupture of infected erythrocytes and release of
parasites |
|
|
Term
|
Definition
-African
-flagellated
-cause sleeping sickness
-transmitted by tsetse flies |
|
|
Term
| two forms of African Trypanosomiasis |
|
Definition
-a slowly developing disease caused by Trypanosoma brucei gambiense (West and Central Africa)
-a rapidly progressing disease caused
by T. brucei rhodesiense (E Africa) |
|
|
Term
| morphology of Trypanosomes |
|
Definition
-mitochondrial DNA in kinetoplast
-outer surface of the organism is densely coated with a layer of glycoprotein, the variable surface glycoprotein (VSG) while in the mammalian host
-In the tse-tse fly, the organism is coated with a protein called procyclic acidic repetitive protein (PARP)
- T. b gamb and T. b rhod are similar
-10-30 microns by 1-3 microns
-central nucleus and single flagellum |
|
|
Term
| more on morphology of Trypanosomes |
|
Definition
-In the bloodstream, the parasite is covered with a glycoprotein coat, called variant
surface glycoprotein (VSG)
-Antibodies are produced against the VSG and eliminate, by complement-mediated lysis and opsonization and phagocytosis, about 99% of the parasites
-The remaining 1% express a different VSG and start dividing and proliferating |
|
|
Term
|
Definition
-bite reaction: A non-pustular, painful, itchy chancre forms 1-3 weeks
after the bite and lasts 1-2 weeks. It leaves no scar
-Parasitemia: Parasitemia and lymph node invasion is marked by attacks
of fever which starts 2-3 weeks after the bite and is accompanied by
malaise, lassitude, insomnia, headache, and edema |
|
|
Term
| treatment of Trypanosomes |
|
Definition
-100% fatal if not treated
-The blood stage can be treated with reasonable success with Pentamidine
isethionate or Suramin
-Cases with CNS involvement are treated with Melarsoprol, an organic
arsenic compound
-The most effective means of prevention is to avoid contact with tsetse flies
-Vector eradication is impractical due to the vast area involved
-Immunization has not been effective due to antigenic variation |
|
|
Term
|
Definition
-changes in personality
-lack of interest
-Morose and melancholic attitude alternating with exaltation
-mental retardation/lethargy
-low speech
-tremors of tongue and lip
-males become impotent |
|
|
Term
|
Definition
-small infectious agents
-can infect most living things
-bacteriophages attack bacteria
-reproduce at high rate (require host)
-can mutate
-acellular (no cytoplasm or organelles)
-no metabolism of their own
-replicate using hosts machinery
-possess DNA, RNA or both |
|
|
Term
|
Definition
-in 1892 shows that the tobacco mosaic disease is caused by an agent
that passes through a porcelain filter |
|
|
Term
|
Definition
-Single or segmented, circular or linear molecule of nucleic acid functioning as
the genetic material of the virus
-Can be single-stranded or double-stranded DNA or RNA (but never both)
-Codes for the synthesis of viral components and viral enzymes for replication |
|
|
Term
|
Definition
-Protein shell surrounding the genome
-Usually composed of protein subunits called capsomeres
-Protect and introduce the genome into host cells. |
|
|
Term
|
Definition
-Composed of phospholipids and glycoprotein
-Derived from host cell membranes by a process called budding
-Depending on the virus, envelopes may be covered by spikes made of
carbohydrates-protein complexes that helps the virus to attach to the
host cell |
|
|
Term
|
Definition
-Nucleic acid surrounded by either a
helical or polyhedral core and covered by an envelope (herpes) |
|
|
Term
|
Definition
Pleomorphic (irregular shape), or
have complex structures |
|
|
Term
|
Definition
|
|
Term
|
Definition
nucleic acid surrounded by a hollow
protein cylinder or capsid and possessing a helical
structure (tobacco mosaic) |
|
|
Term
|
Definition
nucleic acid surrounded by a
polyhedral (many-sided) shell or capsid, usually in the
form of an icosahedron (Mastadenovirus) |
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