Bacillis - Exam 2 Flashcards
Which species of Bacillus is the only consistent pathogen of vertebrates?
B. anthracis
Bacillis is catalase _________, and is important in distinguishing it from which other bacteria?
Catalase positive
Catalase production important to distinguish from Clostridia
When does Bacillus form spores?
When subjected to stress, for protection
True/False. A spore always needs to form a capsule.
False! It does not!
What are the plasmids that are important virulence factors and regulatory genes?
pX01 and pX02
What does the plasmid pX01 contain?
AtxA (Anthrax toxin activator)
AcpA (Anthrax capsule activator)
Gene for edema and lethal toxin
What does the plasmid pX02 contain?
Gene for encoding the capsule
Which form of Bacillis produces a capsule?
Vegetative form
What is the capsule of Bacillis composed of?
D-glutamyl polypeptide
Which type of Bacillis isolates are used for vaccines?
Non-encapsulated isolates because they are avirulent
What is lethal toxin composed of?
Protective antigen (responsible for binding target cells)
and
Lethal factor (responsible for toxicity)
At low doses causes a cytokine “storm” leading to multi-organ disfunction
At higher concentrations produces apoptosis of macrophages
What is edema toxin composed of?
Protective antigen (responsible for binding to target cells)
and
Edema factor (causes electrolyte and fluid loss in affected cells)
What are the two effects of the edema factor?
EF will either kill macrophages or cause edema in tissue
Calcium in combination with __________, allows the spore to survive decades in a dry environment.
Dipicolinic acid
Which species is almost totally resistant to Bacillis anthracis?
Birds