Difference between revisions of "Tissue cyst-forming coccidia"
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+ | ==Toxoplasma== | ||
+ | |||
+ | *1 major pathogenic species called ''Toxoplasma gondii'' | ||
+ | |||
+ | *Causes disease in a wide range of animal species including humans | ||
+ | |||
+ | *Important cause of abortion in sheep | ||
+ | |||
+ | *Zoonotic | ||
+ | **Can cause abortion | ||
+ | **Can cause congenitally aquired defects | ||
+ | |||
+ | *Forms a sporulated oocyst which is only 10μm | ||
+ | **Contains 2 sporocysts with 4 sporozoites | ||
+ | |||
+ | *Transmission through ingesting the intermediate host or via the faecal-oral route | ||
+ | |||
+ | '''Life Cycle''' | ||
+ | *Complex | ||
+ | |||
+ | *Usually indirect | ||
+ | |||
+ | *Gametogeny (sexual stage) is host specific for felids | ||
+ | |||
+ | *Any warm blooded animal can act as a facultative intermediate host | ||
+ | **Asexual reproduction occurs in the intermediate host forming tissue cysts | ||
+ | **Intermediate host swallows sporulated oocysts or tissue cysts | ||
+ | **Can be transferred between intermediate hosts by carnivorism | ||
+ | |||
Toxoplasma can cause [[Pancreas Inflammatory - Pathology#Acute haemorrhagic pancreatitis|acute interstitial pancreatitis]] in systemic toxoplasmosis | Toxoplasma can cause [[Pancreas Inflammatory - Pathology#Acute haemorrhagic pancreatitis|acute interstitial pancreatitis]] in systemic toxoplasmosis | ||
*''T. gondii'' in [[Respiratory Parasitic Infections - Pathology#Toxoplasmosis|pneumonia]] | *''T. gondii'' in [[Respiratory Parasitic Infections - Pathology#Toxoplasmosis|pneumonia]] | ||
*''Toxoplasma gondii'', ''Sarcocystis'' and ''Neospora caninum'' in [[Muscles Inflammatory - Pathology#Protozoa|myositis]] | *''Toxoplasma gondii'', ''Sarcocystis'' and ''Neospora caninum'' in [[Muscles Inflammatory - Pathology#Protozoa|myositis]] | ||
+ | |||
+ | ==Sarcocystis== | ||
+ | *Most infections are asymptomatic | ||
+ | |||
+ | *Heavy infections are causes of chronic wasting in large animals, hide sondemnation and downgrading of carcasses | ||
+ | |||
+ | *''Sarcocystis'' should be differentiated from other tissue-cyst forming coccidia | ||
+ | |||
+ | *There are many species of ''Sarcocystis'' | ||
+ | |||
+ | *Sporulated oocyst has 2 sporocysts containing 4 sporozoites | ||
+ | **Naked oocyst usually seen in faeces as the oocyst wall is very delicate | ||
+ | |||
+ | *Indirect life cycle | ||
+ | |||
+ | *Life cycle alternates between the final and the obligatory intermediate host | ||
+ | |||
+ | *Only one final and one intermediate host | ||
+ | |||
+ | ==Neospora== | ||
+ | *2 main species | ||
+ | **''Neospora caninum'' in the dog | ||
+ | **''Neospora hughesi'' in the horse | ||
+ | |||
+ | *Sporulated oocysts measuring just 10μm | ||
+ | |||
+ | *Oocyst contains 2 sporocysts with 4 sporozoites | ||
+ | |||
+ | *Life cycle similar to ''Toxoplasma gondii'' | ||
+ | |||
+ | *Limited range of warm-blooded intermediate hosts | ||
+ | **Asexual reproduction occurs in intermediate host forming tissue cysts | ||
+ | |||
+ | *Host range of sexual stage is unknown for ''N.caninum'' | ||
+ | **Intermediate host for ''N.hughesi'' is the horse, but the definitive host is unknown | ||
+ | |||
+ | *Route of transmission not fully understood |
Revision as of 09:04, 17 November 2008
This article is still under construction. |
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Toxoplasma
- 1 major pathogenic species called Toxoplasma gondii
- Causes disease in a wide range of animal species including humans
- Important cause of abortion in sheep
- Zoonotic
- Can cause abortion
- Can cause congenitally aquired defects
- Forms a sporulated oocyst which is only 10μm
- Contains 2 sporocysts with 4 sporozoites
- Transmission through ingesting the intermediate host or via the faecal-oral route
Life Cycle
- Complex
- Usually indirect
- Gametogeny (sexual stage) is host specific for felids
- Any warm blooded animal can act as a facultative intermediate host
- Asexual reproduction occurs in the intermediate host forming tissue cysts
- Intermediate host swallows sporulated oocysts or tissue cysts
- Can be transferred between intermediate hosts by carnivorism
Toxoplasma can cause acute interstitial pancreatitis in systemic toxoplasmosis
Sarcocystis
- Most infections are asymptomatic
- Heavy infections are causes of chronic wasting in large animals, hide sondemnation and downgrading of carcasses
- Sarcocystis should be differentiated from other tissue-cyst forming coccidia
- There are many species of Sarcocystis
- Sporulated oocyst has 2 sporocysts containing 4 sporozoites
- Naked oocyst usually seen in faeces as the oocyst wall is very delicate
- Indirect life cycle
- Life cycle alternates between the final and the obligatory intermediate host
- Only one final and one intermediate host
Neospora
- 2 main species
- Neospora caninum in the dog
- Neospora hughesi in the horse
- Sporulated oocysts measuring just 10μm
- Oocyst contains 2 sporocysts with 4 sporozoites
- Life cycle similar to Toxoplasma gondii
- Limited range of warm-blooded intermediate hosts
- Asexual reproduction occurs in intermediate host forming tissue cysts
- Host range of sexual stage is unknown for N.caninum
- Intermediate host for N.hughesi is the horse, but the definitive host is unknown
- Route of transmission not fully understood