Bacillus Spp. Flashcards
What is the O2 requirement for Bacillus?
Aerobic OR Facultative Anaeobes
Where is Bacillus typically found?
Ubiquitous in nature; forms Endospores
T/F: most Bacillus spp. are soil saprophytes
TRUE
What spp. of bacillus is an obligate mammalian pathogen?
Bacillus anthracis
What is the source of infection for herbivores?
Soil contaminated with spores
Microscopically, B, anthracis are seen as ________?
Large, square-end, rods
Medusa head colonies
Virulence factors of B. Anthracis are (2)?
Cell associated and Extracellular
What is the cell associated virulence factor of B. Anthracis?
A Capsule : polymers of D glutamic acid
What is the extracellular virulence factor?
Anthrax Toxin (tripartite toxin) - 3 proteins working together to form toxin
If only capsule present, is B. anthracis virulent?
NO - must have both capsule and anthrax toxin to be virulent
Both virulence factors are encoded by ______________
Plasmids
Bacillus anthracis capsule is produced in vivo OR in vitro?
In vivo
The B. anthracis capsule is made of polymers of ______________
D-glutamic acid
The capsule allows B. anthracis to survive in the host because it is ___________
Anti-phagocytic
Bacillus anthracis can be stained using _______
McFadyean Reaction on stain with polychromatic methylene blue
Anthrax toxin is otherwise known as:
Tripartite Toxin
Three factors make up Tripartite (Anthrax) toxin:
- Edema Factor
- Lethal Factor
- Protective antigen
The combination of the 3 proteins results in:
Increased vascular permeability and cell necrosis
Function of Edema Factor?
- Inhibit neutrophil function
- calmodulin-dependent adenylate cyclase
Function of Lethal Factor?
Cell death, hypoxia-induced tissue injury/shock
-zinc mealloprotease
Protective antigen function?
Prevent entry of toxin into the cell - cell binding factor
-translocation into cell
To produce a vaccine you must have______
Toxin Plasmid (don’t need the capsule)
Strains of anthracis that are encapsulated and toxigenic are considered?
Virulent
Increase expose assoc. with 5 factors:
- history of previous anthrax deaths
- flooding: spores to surface
- soil conditions: alkaline, rich in Calcium and nitrogen favor endospore survival
- warm temps
- drought brings closer to ground to increasing changes of soil ingestion and mechanical injury to GI mucosa
The most common way to develop disease assoc. with Bacillus is?
Exposure to endospores
Endospores germinate within the _____________ of macrophages
Phagolysosomes
Complete anthrax toxin causes ___________ and affects _______________
Cell death and vascular permeability
What is the most susceptible species?
CATTLE
“Anthrax” is associated with what condition?
Septicemia
Pulmonary Anthrax - species and disease?
Human - Wool Sorters Disease
Acute Septicemia
Horse - colic and diarrhea
Per acute septicemia
Ruminants (Cattle*, sheep):
- AM - bleeding from orifices
- PM - Hemorrhagic Exudate
- PM - Splenomegaly
Pharyngeal
Pigs / Dogs - Asphyxia
Intestinal
Human / Pig / Horse
Cutaneous
Human - Malignant Carbuncle
How long can B. anthracis spores persist in the ground?
DECADES - Thus is REPORTABLE
Will you conduct a field necropsy for B. anthracis?
NO! Call the state/federal officials
Staining using McFadyean’s methylene blue will stain B. anthracis ___________
With a pink capsule
In order to diagnose B. anthracis, you use what kind of culture and diagnostic method?
Aerobic culture of blood and PCR
What level BSL is B. anthracis?
BSL-3
T/F: B.anthracis is zoonotic and reportable
TRUE: it is reportable within 9 days
What are the zoonotic diseases associated with B. anthracis?
Cutaneous = Malignant Carbuncle
Pulmonary = Wool Sorter’s Disease (aerogenous)
Intestinal and Oropharyngeal
Anthrax is typically ___________ and lethal
airborne
Treatment of B. anthracis (4)
Penicillin
Tetracycline
Doxycycline
Ciprofloxacin
What is the optimal means of disposal of animals infected with B. anthracis?
Incineration
Differential Diagnosis:
Blackleg - Clostridium chavuoei
Botulism - Clostridium botulinum
