Difference between revisions of "Trypanosoma"

Latest revision as of 17:59, 4 June 2016

Trypanosoma sp
Kingdom	Protista
Phylum	Protozoa
Order	Kinetoplastida
Family	Trypanosomatidae
Genus	Trypanosoma

Schematic diagram of Trypanosoma brucei

Trypanosoma cruzi
CDC/Dr. Myron G. Schultz, WikiMedia Commons

T. cruzi in monkey heart
Dr. L.L. Moore Jr., WikiMedia Commons

Triatoma infestans the Kissing bug - WHO Wikimedia Commons

Chagas endemic zones 2005 - Wikimedia Commons

Introduction

Trypanosomes are elongated unicellular protozoal organisms with an undulating membrane and anterior flagellum.

Lifecycle

The trypanosomes are transmitted by haematophagous insect vectors including the tsetse fly and triatomid kissing bug.

Stercorarian

Stercorarian trypanosomes develop in the posterior gut of the insect and infective metatrypanosomes are excreted in the faeces of the insect onto the skin of the host.

They can then penetrate the tissues, gaining access through skin abrasions or mucous membranes. The metatrypanosomes then multiply within the reticulo-endothelial system of the host, later disseminating throughout the organs invading host cells residing within parasitophorous vacuole. These vacuoles acidify and subsequently release trypomastigotes into the cell cytoplasm. These then develop into amastigotes which divide several times eventually transforming back into trypomastigotes that rupture the host cell. From here they may invade other cells or enter the bloodstream where the opportunity may arise to infect the insect vector. The amastigotes may also burst the host cell and invade other cells.

T. cruzi, the trypanosome of most human importance, is a typical Stercorarian trypanosome and utilises the triatomid “kissing bug” as its vector among others. Disease in dogs may also occur.

T. theileri infects cattle and is transmitted by tabanid flies, stable flies, ticks and mosquitoes.

Salivarian

Salivarian trypanosomes develop in the anterior gut of their vector, the Tsetse fly.

Development occurs in the proboscis and midgut, forming epimastigotes which then invade the hypopharynx and develop into trypomastigotes and then infective metatrypanosomes form.

These are then innoculated into the mammalian host through a bite before a blood meal.

Pathogenesis

Trypanosomes deplete carbohydrates, proteins, lipids and micronutrients from their hosts.

They cause haemolytic anaemia when present within the bloodstream.

Diseases

Trypanosomosis affects the lymphoid and haematopoeitic systems of a wide range of hosts.

Salivarian Species

T. brucei affects all domestic mammals, including small and farm species, and humans. It also causes a specific skin disease in donkeys.

T. vivax infects ruminants, horses and camels causing significant disease.

T. equiperdum causes venereal equine disease dourine. It is the only trypanosome that does not immediately require an insect vector for transmission, being spread through coitus.

T. simiae causes fatal pyrexia in pigs while T. congolense is milder in the same species.

T. congolense can also affect dogs and cats causing acute fever, anaemia and neurological signs.

T. evansi also affects all domestic mammals.

Stercorarian Species

T. cruzi occurs in South America where it is transmitted by a triatomid (kissing) bug and infects armadillos, possums and humans. It is known as Chagas’ Disease. A similar acute disease is thought to be caused by T. cruzi in dogs in the USA.

T. melophagum and T. theileri are non-pathogenic species present in the UK infecting cattle, buffalo and antelope. Stress and concurrent disease are thought to be contributors to the development of clinical disease from T. theileri.

Trypanosoma Learning Resources
Vetstream To reach the Vetstream content, please select	Canis, Felis, Lapis or Equis
Flashcards Test your knowledge using flashcard type questions	Trypanosoma Flashcards Tropical Protozoa Flashcards

References

This article was originally sourced from The Animal Health & Production Compendium (AHPC) published online by CABI during the OVAL Project.

The datasheet was accessed on 6 June 2011.

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-|{{Taxobox
+{{OpenPagesTop}}
+{{Taxobox
 |name               = ''Trypanosoma sp''
 |kingdom            = Protista
 |sub-kingdom        =
-|phylum             = Protozoa
+|phylum             = [[Protozoa]]
 |super-class        =
 |class              =
@@ Line 16: / Line 17: @@
 |species            =
 }}
+[[File:Trypanosoma brucei.gif|thumb|300px|right|Schematic diagram of ''Trypanosoma brucei'']]
 [[Image:Trypanosoma.jpg|thumb|right|150px|''Trypanosoma cruzi'' <br> CDC/Dr. Myron G. Schultz, WikiMedia Commons]]
 [[Image:T.cruzi in monkey heart.jpg|thumb|right|150px|''T. cruzi'' in monkey heart <br> Dr. L.L. Moore Jr., WikiMedia Commons]]
 [[Image:Triatoma infestans.jpg|thumb|right|150px|''Triatoma infestans'' the Kissing bug - WHO Wikimedia Commons]]
 [[Image:Chagas endemic zones 2005.jpg|thumb|right|150px|Chagas endemic zones 2005 - Wikimedia Commons]]
-*Protozoal parasites found in the blood and tissues of vertebrates
+==Introduction==
+Trypanosomes are '''elongated unicellular [[Protozoa |protozoal]]''' organisms with an undulating membrane and anterior flagellum.
-*Worldwide distribution
+==Lifecycle==
+The trypanosomes are transmitted by '''haematophagous insect''' vectors including the '''[[Glossinidae |tsetse fly]]''' and '''triatomid''' kissing bug.
-*Causes sleeping sickness in humans
+===Stercorarian===
+Stercorarian trypanosomes develop in the '''posterior gut''' of the insect and infective '''metatrypanosomes''' are excreted in the '''faeces''' of the insect onto the '''skin''' of the host.
-*Particularly seen in sub-Saharan Africa
+They can then '''penetrate''' the tissues, gaining access through skin abrasions or mucous membranes. The metatrypanosomes then multiply within the reticulo-endothelial system of the host, later '''disseminating''' throughout the organs invading host cells residing within parasitophorous vacuole. These vacuoles acidify and subsequently release '''trypomastigotes''' into the cell cytoplasm. These then develop into '''amastigotes''' which divide several times eventually transforming back into trypomastigotes that rupture the host cell. From here they may invade other cells or enter the bloodstream where the opportunity may arise to infect the insect vector. The amastigotes may also burst the host cell and invade other cells.
-**Affects cattle production
-**Causes Nagana (Wasting disease)
-*Divided into two groups depending on the mode of development in the insect vector
+'''''T. cruzi''''', the trypanosome of '''most human importance''', is a typical Stercorarian trypanosome and utilises the '''triatomid “kissing bug”''' as its vector among others. Disease in dogs may also occur.
-**'''Salivarian'''
-***Multiply in the foregut and proboscis
-***Transmitted via inoculation during feeding
-***Transmitted by [[Glossinidae|''Tsetse'' flies]]
-***Also known as '''anterior station development'''
-**'''Stercorarian'''
-***Multiply in the hindgut
-***Infective form migrates to the [[Rectum - Anatomy & Physiology|rectum]]
-***Transmitted via contamination of wounds with insect faeces
-***Also known as '''posterior station development'''
-*All ''Trypansomes'' except for ''T. equiperdum'' have arthropod vectors
+''T. theileri'' infects cattle and is transmitted by [[Tabanidae |tabanid flies]], [[Stomoxys calcitrans |stable flies]], [[Ticks |ticks]] and [[Culicidae |mosquitoes]].
-**''T. equiperdum'' is a venereally transmitted disease
-*'''Non-cyclical''' transmission can also occur
+===Salivarian===
-**Mechanical transmission
+Salivarian trypanosomes develop in the '''anterior gut''' of their vector, the '''[[Glossinidae |Tsetse fly]]'''.
-**Transferred by interrupted feeding from one host to another
-**Usually transmitted by [[Biting Flies|biting flies]], e.g. [[Tabanidae|''Tabanidae'']] and [[Stomoxys calcitrans|''Stomoxys'']]
-'''Recognition'''
+Development occurs in the '''proboscis''' and midgut, forming '''epimastigotes''' which then invade the '''hypopharynx''' and develop into '''trypomastigotes''' and then '''infective metatrypanosomes''' form.
-*Elongated, spindle shaped protozoa
-*Between 8 and 39 μm in length
+These are then innoculated into the mammalian host through a '''bite''' before a blood meal.
-*Flagellate
+==Pathogenesis==
-**Flagellum runs the length of the body attached to the pellicle which forms an undulating membrane
+Trypanosomes '''deplete''' carbohydrates, proteins, lipids and micronutrients from their hosts.
-*Kinetoplast present which contains the DNA of the single mitochondrion
+They cause '''haemolytic [[Anaemia |anaemia]]''' when present within the bloodstream.
-'''Life Cycle'''
+==Diseases==
-*Undergo morphological transformations in intermediate host before becoming infective for the next host
+[[Trypanosomosis]] affects the lymphoid and haematopoeitic systems of a wide range of hosts.
-*Blood-sucking [[Biting Flies|flies]] ingest trypanosomes whilst taking a blood meal from an infected animal
+===Salivarian Species===
-**Trypanosomes multiply first in the gut of the [[Biting Flies|fly]]
+''T. brucei'' affects '''all domestic mammals''', including small and farm species, and humans. It also causes a specific [[Protozoal Skin Infections - Donkey|skin disease in donkeys]].
-*Salivarian trypanosomes are transmitted by [[Glossinidae|Tsetse flies]]
+''T. vivax'' infects ruminants, horses and camels causing significant disease.
-**Trypanosomes pass forward to the salivary glands where they transform into the infective stage
-**Inoculated with saliva when [[Glossinidae|Tsetse fly]] next feeds on a host
-*Stercorarian trypanosomes are transmitted by triatomid bugs, [[Tabanidae|tabanids]] and [[Melophagus ovinus|keds]]
+''T. equiperdum'' causes '''venereal''' equine disease '''dourine'''. It is the only trypanosome that does not immediately require an insect vector for transmission, being spread through coitus.
-**Trypanosomes pass back to the rectum
-**Next host is infected when skin wounds are contaminated with infected [[Insecta|insect]] faeces
+''T. simiae'' causes fatal pyrexia in '''pigs''' while ''T. congolense'' is milder in the same species.
+''T. congolense'' can also affect '''dogs and cats''' causing acute fever, anaemia and neurological signs.
+''T. evansi'' also affects all domestic mammals.
-==Test yourself with the Protozoa Flashcards==
+===Stercorarian Species===
+'''''T. cruzi''''' occurs in '''South America''' where it is transmitted by a triatomid (kissing)  bug and infects armadillos, possums and humans. It is known as '''''Chagas’ Disease'''''.
+A similar acute disease is thought to be caused by ''T. cruzi'' in dogs in the USA.
-[[Protozoa_Flashcards#Tropical_Protozoa|Tropical Protozoa Flashcards]]
+''T. melophagum'' and ''T. theileri'' are '''non-pathogenic''' species present in the '''UK''' infecting cattle, buffalo and antelope. Stress and concurrent disease are thought to be contributors to the development of clinical disease from ''T. theileri''.
+{{Learning
+|flashcards = [[Trypanosoma Flashcards]]
+[[Protozoa_Flashcards#Tropical_Protozoa|Tropical Protozoa Flashcards]]
+|Vetstream = [https://www.vetstream.com/canis/search?s=protozoa Protozoa]
+}}
+==References==
+<references/>
+{{CABI source
+|datasheet = [http://www.cabi.org/ahpc/?compid=3&dsid=96918&loadmodule=datasheet&page=2144&site=160 ''Trypanosoma'']
+|date = 6 June 2011
+}}
+<br><br><br>
+{{Nick Lyons
+|date = October 29, 2011}}
+{{OpenPages}}
 [[Category:Tropical Protozoa]]
+[[Category:CABI Expert Review Completed]][[Category:CABI AHPC Pages]]
-[[Category:To_Do_-_Steph]]
+[[Category:Nick Lyons reviewed]]