Gram + Rods Anthrax, Flashcards
What are the general characteristics of B. spp.
Large Gram + Rods Endospore forming Thick Peptidoglygcan layer Teichoic and Lipo-teichoic acids NO OUTER MEMBRANE!
What type of pathogen is Bacillus anthracis?
Obligate mammalian pathogen
What type of pathogen is Bacillus cereus
RARE cause of OPPORTUNISTIC infections and food poisoning in animals
What is the insect pathogen in Bacillus spp?
B. thuringiensis
What are most species of Bacillus?
soil saprophytes
How fast do bacillus grow?
Rapid!! kim collins fast- google it!
What type of medium does bacillus grow on?
Gram + selective and non selective media
What type of growth can be expected on MacConkeys Plate?
NONE! MacConkeys is Gram - Selective
What are the hemolytic properties of Bacillus species?
varies
to what level are saprophytes identified?
Genus
What bacteria was used to test Kochs Postulates?
B. antracis
what are the oxygen requirements of B. anthracis?
Aerobic
B. anthracis motile or no?
non-motile
B. anthracis hemolytic or nah?
nah brah they aint
Most endospores protrude through the cell causing a club like appearance, is this characteristic true for B. anthracis?
No, Think of B. anthracis as a purple wedding band with a tiny diamond that barely touches (if even) the membrane. Squared ends
Microscopic evaluation of colonies will show what when looking at B. anthracis?
Medusa head colonies ( shes the one with all the snakes for hair that if you looked at her she turned to stone. The more you know!)
What virulence factors are associated with B. anthracis
Cell associated
Capsule ( NOT POLY SACCHARIDE!)- Polymers of D-glutamic acid
Extracellular
Anthrax Toxin
3 proteins- Edema factor, Lethal factor & protective Antigen
What source of genetics encodes the virulence factors of B. anthracis?
Plasmids
Which plasmids are required for virulence in B. anthracis?
Both Capsule and Toxin
Where is the capsule for B. antracis produced?
Only IN VIVO- IN THE ANIMAL
Capsule biosynthesis operon transcriptionally upregulated by CO_2_/ Bicarb signal
What molecules make up the B. anthracis capsule?
Polymers of D-glutamic acid
encoded by plasmid
Antiphagocytic
What stain associated with B. anthracis and what is the reaction called?
Polychromatic methylene blue
McFadyean rxn.
Capsules stain as pink shadow
What is the Edema factor?
Calmodulin-dependent adenlyate cyclase ( inhibits neutrophil function)
What is the lethal factor?
Zinc metalloprotease (cell death, hypoxia-induced tissue injury/shock)
What is the protective antigen?
Cell binding factor (translocation into cell)
Which factors are required for virulence of B. anthracis?
Edema, Lethal, Protective antigen
What do the three factors of the anthrax toxin cause?
increased vascular permeability and cell necrosis