Difference between revisions of "Lawsonia intracellularis"
Jump to navigation
Jump to search
| Line 1: | Line 1: | ||
<big><center>[[Infectious agents and parasites|'''BACK TO INFECTIOUS AGENTS AND PARASITES''']]</center></big> | <big><center>[[Infectious agents and parasites|'''BACK TO INFECTIOUS AGENTS AND PARASITES''']]</center></big> | ||
<big><center>[[Bacteria|'''BACK TO BACTERIA''']]</center></big> | <big><center>[[Bacteria|'''BACK TO BACTERIA''']]</center></big> | ||
| − | + | ||
===Overview=== | ===Overview=== | ||
| + | *Causes [[Intestines - Proliferative Enteritis#Porcine Adenomatosis Complex|porcine proliferative enteropathy]] | ||
| + | *Grows intracellularly in pircine enterocytes | ||
| + | *Excreted in small amounts in faeces of infected pigs | ||
===Characteristics=== | ===Characteristics=== | ||
| − | * | + | *Slender, curved, Gram negative rod |
| + | *Microaerophilic | ||
| + | *Obligate intracellular bacterium | ||
| + | *Requires enterocyte tissue culture for growth | ||
| + | |||
| + | |||
| + | ===Pathogenesis and pathogenicity=== | ||
| + | |||
| + | *Affinity for porcine enterocytes | ||
| + | *Causes proliferation of enterocytes | ||
| + | *Adenomatous and inflammatory lesions develop in the terminal ilium, caecum and colon | ||
| + | *Synergistic relationship between ''L. intracellularis'' and intestinal flora including ''E. coli'', ''Clostridium'' species and ''Bacteroides'' species | ||
| + | *Intestinal organisms may produce correct oxygen tension and conditions for colonisation of ''L. intracellularis'' | ||
| + | *Infection can only take place in presence of intestinal flora | ||
| + | |||
| + | |||
| + | ===Clinical disease=== | ||
| + | |||
| + | *Proliferative enteropathy occurs in weaned pigs, 6-12 weeks old | ||
| + | *Chronic intermittent diarrhoea with reduced growth or acute haemorrhagic enteropathy | ||
| + | *Sudden heath in severe infections | ||
| + | *Recovery from mild form in most animals without treatment | ||
| + | *Post mortem lesions include thickened wall, mucosal necrosis with clotted blood in the lumen of the ilium, caecum and colon | ||
| + | *Enlarged mesenteric lymph nodes | ||
| + | |||
| + | |||
| + | ===Diagnosis=== | ||
| + | |||
| + | *Clinical signs and pathology give a presumptive diagnosis | ||
| + | *Organisms demonstrated in faeces or ileal mucosa by immunofluorescence or PCR | ||
| + | *Silver impregnation stains or immunostaining or lesions | ||
| + | *Culture in enterocyte cell lines | ||
| + | |||
| + | |||
| + | ===Treatment and control=== | ||
| + | |||
| + | *Antibiotics such as tylosin, tiamulin used prophylactically or therapeutically in feed/water | ||
| + | *Zinc bacitracin in feed | ||
| + | *Thorough cleaning and disinfection of premises | ||
Revision as of 17:04, 26 May 2008
Overview
- Causes porcine proliferative enteropathy
- Grows intracellularly in pircine enterocytes
- Excreted in small amounts in faeces of infected pigs
Characteristics
- Slender, curved, Gram negative rod
- Microaerophilic
- Obligate intracellular bacterium
- Requires enterocyte tissue culture for growth
Pathogenesis and pathogenicity
- Affinity for porcine enterocytes
- Causes proliferation of enterocytes
- Adenomatous and inflammatory lesions develop in the terminal ilium, caecum and colon
- Synergistic relationship between L. intracellularis and intestinal flora including E. coli, Clostridium species and Bacteroides species
- Intestinal organisms may produce correct oxygen tension and conditions for colonisation of L. intracellularis
- Infection can only take place in presence of intestinal flora
Clinical disease
- Proliferative enteropathy occurs in weaned pigs, 6-12 weeks old
- Chronic intermittent diarrhoea with reduced growth or acute haemorrhagic enteropathy
- Sudden heath in severe infections
- Recovery from mild form in most animals without treatment
- Post mortem lesions include thickened wall, mucosal necrosis with clotted blood in the lumen of the ilium, caecum and colon
- Enlarged mesenteric lymph nodes
Diagnosis
- Clinical signs and pathology give a presumptive diagnosis
- Organisms demonstrated in faeces or ileal mucosa by immunofluorescence or PCR
- Silver impregnation stains or immunostaining or lesions
- Culture in enterocyte cell lines
Treatment and control
- Antibiotics such as tylosin, tiamulin used prophylactically or therapeutically in feed/water
- Zinc bacitracin in feed
- Thorough cleaning and disinfection of premises