The Flagellates Flashcards
What are the two morphologic forms of flagellates?
Trophozoites and cysts.
What is the infectious stage?
Ingestion of infected cysts.
Where do trophozoites emerge?
Intestines.
How do trophozoites multiply?
Asexual binary fission
Can trophozoites survive in outside environment?
Possibly, but it depends on the specific flagellate.
Can cysts survive in outside environment?
Yes they can, they continue to develop in outside world for subsequent entry into unsuspecting human.
What is the specimen of choice for recovering extraintestinal flagellates?
- mouth scrapings
- centrifuged urine
- vaginal/urethral discharge
- prostate secretions
How are flagellates differentiated from each other?
- Size
- Shape
- Nuclear structures
- Flagellate number/arrangement
- Cytoplasmic features
- Presence of undulating membrane
What is the only intestinal flagellate considered pathogenic?
Giardia intestinalis.
What are the two intestinal species?
Giardia intestinalis and chilomastix mesnelli
What is the one extraintestinal species?
Trichomonas vaginalis.
How is giardia intestinalis transmitted?
- Contaminated food/water
- Hand-to-mouth
- Unprotected sex
- Circulating flies and cockroaches
Where is giardia intestinalis found?
Worldwide in multiple water sources.
True or false:
Cysts are resistant to routine water chlorination.
True
* chemical and filtration processes required
What populations are at risk for G. intestinalis?
- Children in day care centers
- Individuals in areas of poor sanitations
- Travelers to and who drink contaminated water in endemic areas
- Homosexual males
What are the animal reservoir hosts for G. intestinalis?
Beavers, muskrats, water voles, domestic animals
How often do G. intestinalis trophozoites multiply?
Every 8 hours by longitudinal binary fission.
How do trophozoites attach to mucosa?
Sucking discs.
What are the symptomatic intestinal symptoms of G. intestinalis?
Diarrhea, abdominal cramps, bloating, weightloss, chronic fatigue.
What is the incubation period of Giardia?
10-26 days
* individuals with IgG/A deficiency are susceptible to recurring infections.
What is the epidemiology of Chilomastix mesnelli?
Cosmopolitan - prefers warm climates.
How do you prevent Chilomastic?
Good sanitation and personal hygiene practices.
Where does Trichomonas vaginalis reside in women and men?
Mucosal surface of the vagina in women or prostate gland region.
What do the trophozoites in Trichomonas feed on?
Bacteria and leukocytes.
What is the mode of transmission for Trichomonas vaginalis?
Sexual intercourse and passage from mother to child via birth canal.
True or false:
Trophozoites can survive in urine, on wet sponges, and on damp towels for hours.
True.
What are the symptoms of Trichomonas?
- Dysuria
- Thick vaginal discharge
- Burning on urination
- Vaginal itching
How did Antonie von Leewenhoek obtain the specimen regarding Giardia?
What is the animal reservoir for Giardia?
humans.
Draw the life cycle of Giardia.
How is Trichomonas transmitted? How is this different than most protozoan transmission mechanisms?
Sexual intercorse. This is different because most protozoans are transmitted through fecal-oral route with a cyst stage.
How is the life cycle of Trichomonas different than other flagellates or amoebae?
No cyst stage.
