ORAL AND INTESTINAL FLAGELLATES (copy)

Sarcomastigophora

phylum

Mastigophora

subphylum

Zoomastigophora

class

Trophozoite stage

feeding, motile, replicating stage

watery stool

Cystic stage

resting stage

highly resistant to destruction and can survive outside the host for several stage

formed stool

Giardia lamblia

discovered in 1871 by Anton van leeuwenhoek in his own stool

most commonly diagnosed intestinal parasite in the US

Small intestine

habitat of Giardia lamblia

Mature cyst

infective stage of Giardia lamblia

Axoneme

median line “backbone”

Longitudinal Binary Fission

mode of replication

2 spherical nuclei

young cyst

4 spherical nuclei

mature cyst

Duodenal aspirate or biopsy

if parasite is not found in the feces

demonstrates trophozoites

Entero-test/Entero-string test

demonstrates Giardia lamblia trophozoites

Direct Fluorescent Antibody

gold standard in the US

Metronidazole

one of the first line treatment for Giardia lamblia

Dientamoeba fragilis

believed to be transmitted between human hosts, inside helminth eggs, or larvae, particularly those of Enterobius vermicularis and Ascaris lumbricoides

Iodoquinol

drug of choice for Dientamoeba fragilis

made of iodine

Tetracyline

contraindicated in children under age 8, pregnant, and lactating women

Trichomonas vaginalis

the only pathogenic specie in the genus

largest and stoutest

discovered by Donne in 1836 in purulent secretion of male urogenital discharge and female vaginal discharde

Sexual intercourse

mode of transmission of Trichomonas vaginalis

Trichomonas hominis

non-pathogenic

trophozoite stage only

passed out in diarrheic stools

Cecum

habitat of Trichomonas hominis

Trichomonas tenax

smallest of the species

trophozoite stage only

non-pathogenic; harmless

Oral cavity

habitat of Trichomonas tenax

Kissing

mode of transmission of Trichomonas tenax

Chilomastix mesnili

non-pathogenic; harmless

indicator of fecal contamination of food and water

Retortamonas intestinalis

a small flagellate and is rarely encountered

found in both warm and temperate climates

non-pathogenic; harmless

indication of fecal contamination