Protazoan Organisms Flashcards
Protazoan Organisms
Protozoa
Eukaryotic organisms
Ecologically important
Cause serious human dieases
Protazoan Organisms
How do the protozoa that are motile get around?
Eukaryotic cilia or flagella
Or actin-myosin cytoskeletal mechanisms
Protazoan Organisms
Types of host when a parasite uses multiple hosts
Definitive host
Intermediate host
Protazoan Organisms
Definitive host
A host used by parasites that use multiple hosts
Where parasite reproduces asexually
Protazoan Organisms
Intermediate host
A host used by parasites that use multiple hosts
Where sexual development occurs
Protazoan Organisms
How many hosts do parasites use?
Either one or multiple depending on the parasite
Protazoan Organisms
Excavata
Part of the protist supergroup
Named after “excavated” feeding grove in cell
Food particles taken into the cells by phagocytosis
Protazoan Organisms
Another name fro the feeding grove in excavata cells?
Cytostome
Protazoan Organisms
Process of phagocytosis in excavates
Protazoan Organisms
Four flagellates that cause human diseases
- Trichomonas*
- Giardia*
- Leishmania*
- Trypanosoma*
Protazoan Organisms
Trichomoniasis
Sexually transmitted infection
Caused by Trichomonas vaginalis
Produces vaginits in females
May cause urethritis in males
Protazoan Organisms
Symptoms of trichomoniasis
Pain
Dysuria (painful urination)
Discharge
Protazoan Organisms
Life cycle of Trichomonas vaginalis
Protazoan Organisms
How long can Trichomonas vaginalis last outside the host for?
Normally 1-2 hours
Up to 24 hours in water, semen or urine
Protazoan Organisms
Pathogenesis of Trichomoniasis
Infection caused by contact transmission to genital endothelial cells
These cells are destroyed and inflamation occurs
Protazoan Organisms
Is Trichomonas invasive?
No
It adheres to the vaginal endothelial cells
Protazoan Organisms
What is the treatment for trichomoniasis?
How effective is it?
Oral metronidazole
Cures 95% of cases
Protazoan Organisms
Trypanosoma
Is motile
Has a single flagellum
Has two hosts
Protazoan Organisms
Trypsanosoma hosts
Mammals
Tsetse fly
Protazoan Organisms
What is a vector in terms of parasites?
An agent that carries and transmits the infectious organism
Most commonly insects
Protazoan Organisms
What are the two forms of trypanosomiasis?
- What the cause
- Trypanosoma brucei*
- Causes sleeping sickness
- Trypanosoma cruzi*
- Causes chagas’ disease
Protazoan Organisms
Which is the African form of the Trypanosoma species?
Trypanosoma brucei
Protazoan Organisms
Which is the American form of Trypanosoma species?
Trypanosoma cruzi
Protazoan Organisms
Basic life cycle of Trypanosoma brucei (in human host)
- Tsetse fly injects metacyclic trypomastigotes into human
- Metacyclic trypomastigotes transform into bloodstream trypomastigotes
- Trypomastigotes mutliply by binary fission
- Trypomastigotes taken back up by tsetse fly
Protazoan Organisms
Basic life cycle of Trpanosoma brucei (in tsetse fly)
- Trypomastigotes taken back up by tsetse fly
- Bloodstream trypomastigotes transform into procyclic trypomastigotes in flys midgut
- Procyclic trypomastigots multiply by binary fission
- Procyclic trypomastigotes leave the midgut and transform into epimastigotes
- Epimastigots mutliple in salvitory gland
- They transform into metacyclic trypomastigotes
- Metacyclic trypomastigotes injected into human when fly feeds
Protazoan Organisms
What’s different about members Excavata’s mitochondria?
Often long tubular shape or disc-shaped
Protazoan Organisms
Where is the mitochondrial DNA in Excavata mitochonria?
In a special structure called a Kinetoplast
Protazoan Organisms
What is the reservoir for sleeping sickness?
Human and cattle
Protazoan Organisms
Antigenic variation
When a pathogen can change their cell surface antigens
Fools immune defences
Protazoan Organisms
How does Trypanosoma reproduce
Longitudinal binary fission
In mammalian hosts
Extracellular
Protazoan Organisms
Basic symptoms of Trypanosomiasis
Hemorrhaging
Heacdache
Fever
Skin rash
Impaired mental status
Protazoan Organisms
What further symptoms can a sufferer of Trypasomiasis progress to?
Eventual diminished alertness
Indistinct speech
Tremors
Coma
Coma can lead to death
Protazoan Organisms
Treatment used for trypanosmiasis
If the CNS is involved
- Melarsporol
If there is no CNS involvement
- Pentamidine or Eflorinthine
