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
What is the main reservoir for Bacillis anthracis?
Soil and water
(herbivores are most susceptible)
How is Bacillis transmitted and what is the infectious unit?
Infections takes place by:
- Ingestion of contaminated feed or water
- Via wound infection and arthropod bits
Infectious unit is the endospore
What are the most susceptible species to Bacillis anthracis and what does it cause?
RUMINANTS! (cattle and sheep)
SEPTICEMIA! (and bleeding at body orifices)
True/False. Rigor mortis is often absent with infection of Bacillis?
True
What does Bacillis anthracis cause in horses?
Colic and diarrhea
Edema mainly in point of infection
Septicemia
What tissue is typically infected with Bacillis in swine?
Pharyngeal tissue
What are the three types of anthrax in humans?
Cutaneous anthrax
GI anthrax
Pulmonary or inhalation anthrax
True/False. Bacillis anthracis can contaminate the soil after the animal it was infecting has died.
True
True/False. You should perform a field necropsy on animals suspected of dying from Bacillis anthracis?
FALSE! NO FIELD NECROPSY!!!!!!!!!
What stain is used to ID Bacillis anthracis?
McFadyean’s methylene blue
What is the main treatment for Bacillis anthracis?
Antimicrobial treatment with antiserum
Which type of Bacillis is associated with abortion and bovine mastitis?
Bacillis cereus
Which type of Bacillis is associated with food spoilage?
B. licheniformis
True/False. Bacillis is a reportable disease.
TRUE
True/False. Bacillis is an obligate anaerobe.
FALSE.
Bacillis is a facultative anaerobe
