Difference between revisions of "Bacillus species"
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| − | === | + | ===''Bacillus anthracis''=== |
| + | |||
| + | *Saprophyte in soil | ||
| + | *Capsule composed of homopolymer of D-isomer of glutamic acid allows survival in the body by resisting phagocytosis | ||
| + | *Capsule stains mauve with polychrome methylene blue in the MacFadyean's reaction - identify anthrax in blood samples | ||
| + | *Bacilli appear as chains of dark blue, square-ended rods surounded with the capsule | ||
| + | *Extracellular toxin (holotoxin) composed of oedema factor, protective factor and lethal factor | ||
| + | * | ||
| + | |||
| + | |||
| + | ===''Bacillus licheniformis''=== | ||
| + | |||
| + | *Widespread in the environment | ||
| + | *Associated with food spoilage | ||
| + | *Abortion in cattle and sheep, possibly from spoiled silage or hay | ||
Revision as of 12:37, 17 May 2008
- CAR bacillus in URT infection in cattle and URT infection in rabbits
- Can cause vascular fragility, leading to haemorrhagic disease.
Overview
- Mostly non-pathogenic environmental organisms
- Bacillus anthracis causes anthrax
- Bacillus licheniformis may cause shoradic abortions in cattle and sheep
- Bacillus cereus causes food poisoning in humans and mastitis in cows
Characteristics
- Large, Gram positive rods
- Produce endospores
- Aerobes or facultative anaerobes
- Grow on non-enriched media
- Motile
- Catalase positive, oxidase negative
- Bacillus anthracis colonies are up to 5mm diameter, flat, dry, grey, with a ground-glass appearance; curled outgrowthsfrom the edge of the colony give a 'medusa head' appearance; non-haemolytic (differentiate from Bacillus cereus)
- Bacillus licheniformis forms dull, rough, wrinkled colonies, with hair-like outgrowths
- Biochemical tests for identification
- Can often tolerate adverse environmental conditions
Bacillus anthracis
- Saprophyte in soil
- Capsule composed of homopolymer of D-isomer of glutamic acid allows survival in the body by resisting phagocytosis
- Capsule stains mauve with polychrome methylene blue in the MacFadyean's reaction - identify anthrax in blood samples
- Bacilli appear as chains of dark blue, square-ended rods surounded with the capsule
- Extracellular toxin (holotoxin) composed of oedema factor, protective factor and lethal factor
Bacillus licheniformis
- Widespread in the environment
- Associated with food spoilage
- Abortion in cattle and sheep, possibly from spoiled silage or hay