Phylum Sarcomastigophora Flashcards
What is the common name of the Subphylum Mastigophora?
The Flagellates –> flagella present in trophozoites
What are the main features of Family Trypanosomatidae?
Require an IH - arthropods
Cause death in humans and animals
Extracellular and intracellular location
Genus Trypanosoma
Genus Leishmania
Spindle shaped body One flagellum Underlating membrane Contains a kinetoplast Many phases of development Many species change the body form depending on the host and organ in which they are located
what are the main features of Genus Trypanosoma?
Widespread in the trypomastigote form
Live in blood and tissues
Binary fission
All species except T. equiperdum are transmitted by vectors
Contain 2 groups
- Salivaria: within anterior part of GIT (salivary glands of vector)
- Stercoraria: within posterior part of vector - faecal contamination
What are the features of Trypanosoma - Group Salivaria
Spindle shape
Blunt posterior end
Kinetoplast in terminal position
Free flagellum at anterior end can be present
What are the features of Trypanosoma - Group Stercoaria
Free flagellum always present
Posterior end is pointed
Kinetoplast is subterminal
What are the general features of Trypanosoma evansi / brusei?
Cause Sura disease
Within horses, donkey,s mules, deer, camels, Llamas, dogs, cats
Posterior end is thin, free flagellum and underlating membrane
Located in the circulation
Transmitted by Tabanus spp of fly (no development) –> very painful as it is not easy to get blood from host –> will cause pain and receive a small amount of blood before moving to another host and infecting them
What are the general features of Trypansoma equiperdum?
Affects horses, donkeys and mules
Not in Aus
Transmitted via sex (venereally)
Causes acute or chronic illness
What are the general features of Trypansoma brucei?
T. b. brucei
T. b. gambiense
T. b. rhodesiense
Transmitted by Glossina species –> development within fly)
What are the general features of the subspecies Trypansoma brucei brucei?
Not within humans
Pathology in many species including horses and cattle
Contain 2 forms - 1 in host and 1 in fly
many hosts
Trypomastigote is within blood of the host
Invades the cerebrospinal fluid
In the vertebrate –> trophomastigote
In the vector –> epimastigote
Transmission via flies
Which species of Trypansoma causes African Sleeping sickness?
Trypansoma brucei gambiense
Trypanosoma brucei rhodesiense
What is the main features of Genus Leishmania?
Within in tropical, subtropical and temperate areas (Not Aus)
Causes severe disease in humans and animals
Transmitted via the bite of female sandflies
Zoonotic
More than 14 species can infect humans and cause:
- Visceral disease
- Cutaneous disease
- Musculo-cutaneous disease
Within dogs –> can cause visceral and cutaneous disease (L. infantum)
Have 2 forms:
- Amastigotes –> mammals and in macrophages. Contain a rudimentary flagellum that does not project beyond the body –> not motile
- Promastigote –> in sandflies, have motility and working flagellum.
What is the lifecycle of Genus Leishmania?
When feeding on an infected host, the female sandfly will ingest macrophages
Amastigotes within the macrophages that have been ingested by the female sandfly form into promastigotes, they divide by binary fission and then when the female sandfly feeds, will transfer into the host.
Promastigotes are then released into the blood of the host and are phagocytised by macrophages –> form into Amastigotes and divide in the host cells –> amastigotes will burst the cell, release into blood and invade other cells.
What cases of Leishmania in Australia have been seen?
In 2004, Kangaroos in the NT contained skin lesions on the ears, tail and limbs, the Leishmania species was identified.
What are the general features of Order Trichomonadida?
Flagellate protozoa that inhibit the alimentary canal / urogenial system of vertebrates and invertebrates
Contain an undulating membrane and is bordered by a flagellum
Body is pyriform (rounded anterior and pointed posterior end)
One nucleus
3-5 anterior flagella and a posterior or recurrent flagellum which is incorporated into the undulating membrane
Contains a free flagellum
Reproduce via binary fission
What is the main features of Trichomonas gallinae?
Host - birds, mainly from Columbiformes (pigeons and doves) as well as budgies, hawks, eagles, chickens, etc.
Located in the Digestive tract, mouth, pharynx, oesophagus and crop
Adult pigeons are asymptomatic carriers
Young pigeons are symptomatic, degeneration in oral and nasal cavities
Contain 4 anterior flagella, no free posterior flagellum.
Undulating membrane does not reach posterior end of body
Parasites develop in the mouth and block the feeding and airway –> young birds will die, if they survive, will become carriers
What are the routes of transmission for Trichomonas gallinae?
Transmission via Columbiforms (pigeons and doves) ‘‘pigeon milk’ –> feeding of offspring with secretions from the mucous membrane of the mouth. transmit protozoa that way
Raptors and hawks - infected via ingestion of infected pigeons
Chickens infected via sharing water dishes with pigeons and doves
What is the main features of Tritrichomonas foetus?
Infect:
- Cattle (reproductive tract –> infertility and abortion)
- Cats (diarrhoea)
- Pigs
Pyriform shape (rounded anteriorly, posteriorly pointed
One nucleus, 4 flagella with three anterior (free) and the 4th extending posteriorly along the undulating membrane and trails as free flagellum (long)
What are the main features of Tritrichomonas foetus in cattle?
causes infertility and abortions
Transmission from bulls to cow sexually (coitus)
Bulls –> parasites located in the preputial cavity and urethral oriface. Are Asymptomatic carriers
Cows –> parasites located in vagina and cervix –> move into uterus
What are the main features of Histomonas melegridis?
Causes entero-hepatitis / blackhead disease
Hosts - galliform birds (mainly turkeys)
Infects caeca and liver
Do not survive in environment - transmit sexually, via milk and arthropods
Heterakis gallinarum is a vector for transmission of Histamonas meleagridis.
Pleomorphic shape (dependent on location) --> Caecal lumen form contains one flagellum only. Tissue form does not have flagella and is a cyst-like form
The tissue form exists in eggs of Heterakis gallinarum
What is the lifecycle of Histomonas meleagridis?
Transmission via Heterakis gallinarum –> acts as a vector for Histamonas.
Histamonas infects Heterakis gallinarum within the ovaries of the female –> become incorporated in the eggs. Within the eggs –> Histomonas can survive a long time
Infection of the birds
- occurs through ingestion of embryonated eggs from Heterakis gallinarum that contain Histomonas
- Ingestion of Earthworms (IH of H. gallinarum) that contain larvae of Heterakis gallinarum which then also contain histomonas meleagridis.
In the caeca of the host, histomonas multiply via binary fission and enter the bloodstream and meet at the liver.
Causes enlargement of the caeca and yellow faeces
The second transmission is direct, via cloacal drinking –> Less likely due to the short lifespan in environment
As Histomonas most would be killed by the acidity of the stomach, they move backwards to the caeca.
With lots of Diarrhoea on the ground and the birds have contact with the cloaca with it, it will cause antiperistalsis and the protozoa will move backwards along the GIT to the caeca. This way, it avoids the stomach.
Chickens are not too badly affected, turkeys will die.
What is the main features of the Genus Giardia?
Most common enteric protozoan pathogen that infects humans. Bery common in beef, dairy cattle, dogs and cats
Causes acute and chronic diarrhoea
There are 6 species
- G. duodenalis
Located in the small intestine either free in lumen or attached to the mucosa
Divide by binary fission
Have two forms –> Trophozoite: pear shaped, ventral surface is flat, dorsal surface is convex, contain a ventral disc and 4 pairs of flagella. 2 nuclei
Cyst form: oval, 2-4 nuclei, contain axonemes of flagella, fragments of adhesive discs. Be found in environment. Smaller than trophozoite, tough, can contain more than 1 trophozoite.
What is the lifecycle of Genus Giardia?
Infection of host via infestion of cysts with water or food
Excystation occurs in the stomach when exposed to HCl and pancreatic secretions. Trophozoites excyst fully in small intestine. Divide by dinary fission, invade large areas of intestine, cause pathology.
Encystation of trophozoites occurs in the mid to lower jejunum when exposed to bile salts and pH change (identifies they are close to exiting host, cyst helps them survive)
If the host has diarrhoea, they will not have time to form a cyst and will exit into the environment and die as trophozoite - not resistant
What are the main features of Phylum Ciliophora (ciliates)?
Contain free living forms
Important for medical and veterinary industries
Contain a lot of cilia, smaller, similar cycle to Genus Giardia
Genus Balantidium –> Balantidium coli
What are the main features of Balantidium coli?
Host - humans, pigs
Located in the large intestine as a commensal species (do not cause pathology - cannot penetrate host on its own)
If host is healthy - will not cause infection - just sits in intestine
If a lesion of the large intestine occurs - the B. coli enter the lesions causing ulcers and disease
Pigs can be a reservoir for humans
Contain trophozoite and cyst
- Trophozoite: smaller size, oval shape, contain many cilia, peristome that leads to the cytostome and cytopharynx. Contain 2 nuclei (macronucleus and micronucleus), 2 contractile vacuoles and a food vacuole.
- Cyst: ovid shape, wall is thick, contain a macronucleus, micronucleus, contractile vacuole.
