BY2012 Microbiology Gallery of Trypanosomatid Flagellates

Trypanosoma brucei

Colourised scanning electron micrograph of Trypanosoma brucei surrounded by red blood cells in a smear of infected blood

Trypanosoma brucei Life Cycle

Tsetse Fly Vector – Glossina species

Tsetse Fly - Africa

Trypanosoma brucei – FlagellateUndulating membrane

Microtubules of pellicle

Free Flagellum

Attached flagellum

Fold in pellicle

Golgi

Endoplasmic reticulum

Nucleus

Basal body

Mitochondrion

Kinetoplast

The Cause of Sleeping Sickness

Trypanosoma brucei - Flagellate

Trypanosoma brucei Polymorphic Bloodstream Forms

Trypanosoma brucei Polymorphic Bloodstream Forms

LTF

SF

LTF

SF

IF

IF

LGF = Long thin form; SF = Stumpy form; IF = Intermediate form

SF

Trypanosoma brucei

Nucleus

Kinetoplast

Free flagellum

Undulating membrane

Attached flagellum

Mitochondrion

Trypanosoma brucei

Blood film Phase contrast micrograph

10 µm10 µm

NucleusKinetoplast

Free flagellum

Undulating membrane

Trypanosoma brucei

kinetoplast

mitochondrion

Trypanosoma brucei

A = Nucleus; B = Kinetoplast; C = Undulating membrane; D = Free flagellum

Trypanosoma brucei

Stained with immunofluorescent antibodies (green) and DAPI (blue) to reveal DNA

Nucleus

KinetoplastUndulating membrane

Free flagellum

Trypanosoma brucei

Flagella (red) stained with rhodamine-labelled immunofluorescent antibodies, nuclei and kinetoplasts (blue) stained with DAPI and basal bodies

(green) stained with fluorescein-labelled immunfluorescent antibodies

Trypanosoma cruzi

Colourised scanning electron micrograph of Trypanosoma cruzi surrounded by red blood cells in a smear of infected blood

Geographic Distribution of Chagas Disease [American Trypanosomiasis]

Trypanosoma cruzi

Triatomine Bug – Blood-Sucking Assassin or Kissing Bug [Vector]

When Triatoma bugs bite and ingest blood, they defaecate on the person. Triatomine bugs pass T. cruzi in their faeces which are left near the site of the bite wound. Scratching the site of the bite causes the trypanosomes to enter the host through the wound. The trypanosomes replicate is tissue and are then released into the bloodstream. When a triatome bug takes a blood meal, the trypanosomes are ingested, and a new cycle of replication occurs in the triatome bug.

Trypanosoma cruzi

Nucleus

Kinetoplast

Undulating membrane

Free flagellum

Trypanosoma cruzi - Flagellate

Nucleus

Kinetoplast

Flagellum

Trypanosoma cruzi - Flagellate

Trypanosoma cruzi in blood film

Kinetoplast

Nucleus

Free flagellum

Undulating membrane

Trypanosoma cruzi - Flagellate

Scanning electron micrographs of T. cruzi

Undulating membrane

Leishmania donovani

Colourised scanning electron micrograph of Leishmania donovani

Leishmania donovani

Leishmania donovani - Sandfly

[Phlebotomus papatasi]

Biting, blood-sucking dipterans encountered in sandy areas

Leishmania donovani

Leishmania donovani Promastigotes

Leishmania donovani promastigotes are a life-cycle stage of trypanosomatid flagellates that develop in the sandfly gut and are transmitted to man by bites

Nucleus

Kinetoplast

Flagellum

Trypanosomatid Flagellates in Animals

Trypanosoma rotatorium

T. rotatorium lives in the blood of frogs (Rana). It is non-pathogenic. Note nucleated frog red blood cells

Flagellum

Undulating membrane

Trypanosoma carassii

T. carassii is a widespread parasite of carp and other freshwater fish. It lives extracellularly in the blood and tissues of its hosts. Note nucleated fish red blood cells.

Trypanosoma equiperdum

Dourine is a chronic trypanosomal disease of equids caused by Trypanosoma equiperdum. The disease is transmitted almost exclusively by coitus and is characterized by swelling of the genitalia, nervous system involvement, and progressive emaciation.

Cryptobia salmositica

Nucleus

Kinetoplast Flagellum

Flagellum

Cryptobia differ from Trypanosoma in having two flagella, one at each end of the cell. Cryptobia salmositica is found in carp, goldfish and tench. Fish infected with Cryptobia are listless and swim abnormally. They become emaciated, with sucken eyes and pale gills (indicating a lack of red blood cells). Severely affected fishes die.

Crithidia bombi

Crithidia exclusively infect arthropods, mainly insects. They pass from host to host as cysts in faeces. Typically the parasites develop in the digestive tracts of insects and interact with the intestinal epithelium using their flagellum. Crithidia has a mastigotic life cycle. Crithidia bombi is a parasite of bumblebees. C. bombi infection may cause Colony Collapse Disorder and prevent colony founding by bumble bees.

Cysts