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| [[Neospora]] | | [[Neospora]] |
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− | ==Sarcocystis==
| + | [[Sarcocystis]] |
− | [[Image:Sarcocystis Life Cycle.jpg|thumb|right|150px|''Sarcocytis'' Life Cycle Diagram - Dennis Jacobs & Mark Fox RVC]]
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− | [[Image:Sarcocystic.jpg|thumb|right|150px|''Sarcocytis'' - Joaquim Castellà Veterinary Parasitology Universitat Autònoma de Barcelona]]
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− | [[Image:Sarcocystis in sheep oesophagus.jpg|thumb|right|150px|''Sarcocystis'' in sheep oesophagus - Adam Cuerden]]
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− | [[Image:Equine protozoal myeloencephalitis.jpg|thumb|right|150px|Equine protozoal myeloencephalitis - Wikimedia Commons]] | |
− | [[Image:Sarcocystis cruzi.jpg|thumb|right|150px|''Sarcocystis cruzi'' - Courtesy of the Laboratory of Parasitology, University of Pennsylvania School of Veterinary Medicine]]
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− | *Most infections are asymptomatic
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− | *Heavy infections are causes of chronic wasting in large animals, hide condemnation and downgrading of carcasses
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− | *''Sarcocystis'' should be differentiated from other tissue-cyst forming coccidia
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− | *There are many species of ''Sarcocystis'' which differ in size from microscopic to several centimetres in length
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− | **''S.neurona'' is an important equine pathogen in the USA
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− | *Infective cyst in the intermediate host is called a '''sarcocyst'''
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− | '''Life Cycle'''
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− | *The individual life cycle of some species is incompletely understood
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− | *Indirect life cycle
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− | *Life cycle alternates between the final and the obligatory intermediate host
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− | *Only '''one''' final and '''one''' intermediate host
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− | *Sporulated oocyst has 2 sporocysts containing 4 sporozoites
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− | **Naked sporocyst usually seen in faeces as the oocyst wall is very delicate
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− | **Oocyst measures 15μm in length
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− | *No schizogony in final host
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− | *Gametogeny occurs deep in subepithelial tissue
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− | *Faecal oocyst count is low
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− | *Oocysts are sporulated when passed
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− | **Difficult to find on faecal examination as the sporocysts are few in number and small
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− | *Ingestion of sporocyst by intermediate host
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− | **2 phases of rapid asexual reproduction in vascular endothelial cells
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− | **Slow multiplication of bradyzoites in muscle tissue
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− | **Sarcocyst forms with bradyzoites inside, surrounded by a cyst wall and divided into compartments
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− | '''Epidemiology'''
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− | *Final hosts are carnivores and omnivores
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− | *Intermediate hosts are herbivores and omnivores
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− | *Humans are the final host for some species and the intermediate hosts for others
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− | **Final host for species infecting cattle and pigs
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− | *Dogs are final hosts for species infecting cattle, sheep, goats, pigs and horses
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− | *Cats are final hosts for species infecting cattle, sheep and pigs
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− | '''Pathogenesis'''
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− | *Widespread infection but mostly asymptomatic
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− | *Cause meat inspection losses
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− | *''Sarcocystis'' in [[Muscles Inflammatory - Pathology#Protozoa|myositis]]
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− | *Experimental infections cause severe, acute pyrexic disease when the organism multiplies in the vascular endothelium
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− | *Can cause chronic wasting disease in cattle and horses
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− | **Causes abortion and post-natal disease in sheep
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− | *Equine protozoal myeloencephalitis
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− | **Necrotising encephalomyelitis affecting the grey and white matter of the CNS
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− | **Caused by ''S.neurona''
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− | **Opossum thought to be the definitive host
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− | **Horses thought to be accidental hosts
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− | **Natural intermediate hosts currently unknown
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− | **Western Blotting shows 50% of horses in the USA are seropositive
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− | **Risk factors poorly understood
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− | **Causes spinal cord dysfunction
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− | ***Ataxia and paralysis
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| ==Toxoplasma== | | ==Toxoplasma== |
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| ==[[Protozoa Flashcards - Wikibugs#Tissue Cyst Forming Coccidia|Tissue Cyst Forming Coccidia Flashcards]]== | | ==[[Protozoa Flashcards - Wikibugs#Tissue Cyst Forming Coccidia|Tissue Cyst Forming Coccidia Flashcards]]== |
− | [[Category:Piroplasmida]]
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