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19 Cards in this Set
- Front
- Back
GeneralCharacteristics of Bacillus
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Gram positive rod
spore former Produce endospores
a member of the phylum Firmicutes ~ 60 species; Gram-positive orGram-variable bacilli |
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Habitat |
Ubiquitous, found everywhere!
Soil, water, and airborne dust
Most are saprophytic andare isolated as contaminants Others are opportunist |
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What type of endospores does it create?
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-Central endospores
- The spores are resistant to heat, cold, radiation, desiccation, and disinfectants and need oxygen |
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What type of respiratory conditions may they require?
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Aerobic or facultative anaerobic
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Cell wall
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-The cell wall is composed of teichoic and teichuronic acids.
-actin-like cytoskeleton in cell shape determination and peptidoglycan synthesis , - The role of the cytoskeleton in shape generation and maintenance is important |
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History |
-The genus Bacillus was named in 1835 by Christian Gottfried Ehrenberg,
- earlier named as genus Bacterium |
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Can flourish in what pH
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Extreme pH - from pH 2-10
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Optimum Temperature |
The optimum temperature for growth varies from 25°C to 37°C
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Significant Bacillus Species
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Bacillus anthracis- Agent ofanthrax, a disease in livestock .Humans acquireinfection by contamination of wound or ingestion or inhalation of spores
Bacillus cereus -Causes foodpoisoning .An opportunist Bacillus subtilis -Commonlaboratory contaminant |
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virulence factors
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hemolysin BL, ecithinaselike activity; phosphatidylcholine hydrolase ( phospholipase C.)
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Pathology
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cause an array of infections from ear infections to meningitis, and urinary tract infections to septicemia.
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Clinical Manifestations
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-Self limited food poisoning, localized infections related to trauma (e.g. ocular infections), deep seated soft tissue infections, and systemic infections (e.g. meningitis, endocarditis, osteomyelitis, and bacteremia).
Fulminant eye infections . The various species implicated in serious infections include B. cereus, B. subtilis, B. sphaericus, B. alvei, B. laterosporus, B. licheniformis, B.megaterium and B. pumilus. |
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Laboratory Diagnosis
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Most Bacillus spp grow readily on nutrient agar or peptone media. MYP agar,Mannitol-Eigelb-Polymyxin-Agar (Basis) ,Compass Bacillus cereus Agar
phage typing has been a useful epidemiological tool.A commercially available ELISA can be used for the detection of Bacillus diarrheal enterotoxin in a variety of foods and feces. |
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How do Bacillus species look in Blood Agar?
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-Large spreading colonies -Gray/white color -Have irregular margins
-Many are beta-hemolytic (helpful in differentiatingvarious Bacillus species from B. anthracis). |
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complication
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Endocarditis, Bacteremia ,Musculoskeletal Infections ,Meningitis
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Industrial significance |
-Bacillus amyloliquefaciens is the source of a natural antibiotic
-protein barnase (a ribonuclease), -alpha amylase used in starch hydrolysis, -the protease subtilisin used with detergents, and -the BamH1 restriction enzyme -create GMOs Corns that are resistant to some insect pests. -Use as model organism |
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Treatment |
clindamycin , Gentamicinand vancomycin
-Newer drugs e.g. imipenem , Doxycycline and quinolones |
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PREVENTION
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proper food handling.
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Image |
For more information microamaze.blogspot.com
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