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Porcine Intestinal Spirochaetosis (view source)
Revision as of 10:25, 17 June 2011
, 10:25, 17 June 2011no edit summary
[[Category:To Do - Steph]]
Also Known As – '''''PIS – Porcine colonic spirochaetosis – Spirochaetal diarrhoea'''''
Caused By – ''Brachyspira pilosicoli''
==Introduction==
[[File:[[File:Intestinal spirochetosis - cropped - very high mag.jpg|thumb|200px|right|Intestinal spirochetosis - note the hyperchromatic fuzzy appearance of the brush border adjacent to the lumen. This is the attached spirochaetes. Wikimedia Commons.]]]]
Porcine spirochaetosis is a '''[[Alimentary System - Anatomy & Physiology|gastrointestinal]] disease of pigs''' caused by the '''gram negative anaerobic'''[[Bacteria|bacterium]], '''''Brachyspira pilosicoli'''''. The bacterium can be recognised by its 8-12 flagellae, inserted at each pole of the cell.
The pathogen colonises the '''lumen and crypts of the large intestine''', attaching firmly at one end of the cell to the epithelium.
PIS is also '''zoonotic''' and is associated with chronic diarrhoea and rectal bleeding in humans.
This disease is '''notifiable''' to the World Organisation for Animal Health [http://www.oie.int/ (OIE)]
==Distribution==
Porcine spirochaetosis is present in many significant pig rearing countries, including the '''UK, Europe, Scandinavia, USA, Canada, Brazil and Australasia.'''
Transmission is mainly '''faecal: oral.'''
The bacterium can remain viable in lake water for up to 2 months, providing another route of transmission.
Birds and rodents may act as vectors for disease.
==Signalment==
''B. pilosicoli'' has also been isolated from '''people, dogd, waterfowl, chickens and guinea pigs.'''
Clinical disease is most common in pigs followed by birds.
'''Overcrowding and movement''' of pigs between sites predisposes them to infection and clinical disease.
Infection is most common in 8-14 week old piglets, particularly within 1-2 weeks of moving and mixing batches.
==Clinical Signs==
Clinical disease is generally '''mild.'''
'''Grey or grey-green [[Diarrhoea|diarrhoea]]''' which may contain blood or mucus, and colitis
'''Sub-optimal growth rates and feed efficiency.''' Pigs may require up to 28 additional days to reach slaughter weight.
Occasionally, pigs may become depressed and lethargic.
==Diagnosis==
''B. pilosicoli'' can be cultured from faeces or intestinal samples and isolated on '''blood agar''' with selective antibiotics in '''anaerobic''' conditions. Colonies are '''weakly haemolytic''' and can be definitively identified as spirochaetes under phase contract or dark field microscopy.
'''PCR''' can then confirm species identification.
On '''post-mortem''', animals are in poor body condition and oedema is common between the coils of the large intestine. When the colon is opened, the mucosa is '''erythematous''' in patches.
Histologically, a '''fake brush border of attached spirochaetes''' is pathognomic.
==Treatment==
'''Lincomycin and Tiamulin''' are the most common antibiotics used against PIS, given in water or by injection.
==Control==
At risk pigs are sometimes given prophylactic antibiotics although this use is controversial.
Mixing and moving pigs should be avoided where possible.
Feeding meal or mash may reduce the occurrence of diarrhoea.
{{Learning
|flashcards = [[Porcine Intestinal Spirochaetosis Flashcards]]
}}
==References==
<references/>
Animal Health & Production Compendium, '''Porcine Intestinal Spirochaetosis datasheet''', accessed 16/06/2011 @ http://www.cabi.org/ahpc/
Animal Health & Production Compendium, '''Brachyspira pilosicoli datasheet''', accessed 16/06/2011 @ http://www.cabi.org/ahpc/
[[Category:To Do - CABI review]]