Difference between revisions of "Salmonella"
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| Line 40: | Line 40: | ||
*Utlise citrate as a carbon source | *Utlise citrate as a carbon source | ||
*Usually produce hydrogen sulphide | *Usually produce hydrogen sulphide | ||
| + | *Most motile with flagellae (H antigen) | ||
| + | *H antigen can be in phase 1 or phase 2, depending on a genetic switch allowing for one of the H antigen genes to be transcribed | ||
===Classification=== | ===Classification=== | ||
| Line 45: | Line 47: | ||
*Single species, ''Salmonella enterica'' | *Single species, ''Salmonella enterica'' | ||
*Over 2400 pathogenic serotypes or serovars identified | *Over 2400 pathogenic serotypes or serovars identified | ||
| + | *Grouped into 9 groups according to O antigen (lipopolysaccharide) by the Kauffmann-White scheme - determined by slide agglutination of the bacteria with specific antisera | ||
| + | *Categorised into serovars depending on and H (flagellar) antigen, e.g. ''Salmonella enterica'' subspecies ''enterica'' serovar Tymphimurium; must also determine phase of H antigen | ||
===Pathogenesis=== | ===Pathogenesis=== | ||
Revision as of 18:23, 16 February 2008
- Some serotypes tend to be more species specific, whereas others can affect a wide range of species. For example:
- Salmonella enteritidis
- Salmonella typhimurium
- Widespread in most species.
- Salmonella dublin
- Cattle
- Salmonella cholerae suis
- Pigs
- Usually speticaemic.
- A cause of ulcerative enteritis in the pig.
- Not very common now.
- Salmonella montevideo
- Produces outbreaks from contaminated imported meat and bone meal.
- Salmonellosis
- * Can cause haemorrhagic disease by secondary thrombocytopenic disease.
- Salmonella in Osteomyelitis
- In arthritis of horses
Overview
- Important member of the enterobacteria
- Cause disease in humans and animals
- Oral transmission
- Reservior of infection in poulty, pigs, rodents, cattle, dogs
- Cause enteritis and systemic infection (septicaemia and abortion)
- Salmonella may be carried sub-clinically
- Some human strains cause enteric fever (S. Typhi causes typhoid), also gastroenteritis, septicaemia or bacteraemia
Characteristics
- Facultative intracellular pathogens
- Non-lactose fermentor
- Do not produce urease or indole from tryptophan
- Utlise citrate as a carbon source
- Usually produce hydrogen sulphide
- Most motile with flagellae (H antigen)
- H antigen can be in phase 1 or phase 2, depending on a genetic switch allowing for one of the H antigen genes to be transcribed
Classification
- Single species, Salmonella enterica
- Over 2400 pathogenic serotypes or serovars identified
- Grouped into 9 groups according to O antigen (lipopolysaccharide) by the Kauffmann-White scheme - determined by slide agglutination of the bacteria with specific antisera
- Categorised into serovars depending on and H (flagellar) antigen, e.g. Salmonella enterica subspecies enterica serovar Tymphimurium; must also determine phase of H antigen