Bacillus Flashcards
What type of animals are susceptible to B. anthracis
Herbivores
What type of animals are resistant to B. anthracis
Carnivores and birds
B. anthracis spores formed at what temperature?
15-40°C
TRUE or FALSE:
B. anthracis sporulation requires high CO2 tension
FALSE
sporulation inhibited by high CO2 tension
TRUE or FALSE:
B. anthracis are facultative aerobes
FALSE:
Bacillus anthracis is an obligate aerobe
B. anthracis spores germinate at what temperature and duration?
65°C for 15 mins
B. anthracis vegetative cells are killed at what temperature and duration?
60°C for 30 mins
What are the sources of infection of B. anthracis?
- Soil
- Bone meal and vegetable protein
- Wool and hair
- Tannery effluents
- Bloodsucking flies and carrion eaters
What are the proteins are produced by B. anthracis that forms the Holotoxin
- Edema Factor
- Protective Antigen
- Lethal Factor
What are the Net effect of holotoxin of B. anthracis
- Damage and kill phagocytes
- Increased capillary cell permeability
- Damage clotting mechanism
- Inhibit bactericidal activity of serum
A form of Anthrax thru wound on skin; cutaneous form; malignant carbuncle
or pustule
Localized anthrax
A form of Anthrax More often in humans than in animals
Localized anthrax
What’s the main cause of death of Anthrax in swine and dogs?
Suffocation
A form of Anthrax from airborne spores; pulmonary or inhalation anthrax;
woolsorter’s disease
Generalized anthrax
What is the morphology of B. anthracis in tissues?
Short chains with rounded ends, single capsule
What is the morphology of B. anthracis in cultures?
Long chains with square ends, Medusa-head colonies
What is the size of B. anthracis rods?
1 µm x 3-6 µm
What is the appearance of B. anthracis colonies on agar?
Ground glass-like with irregular margins (Medusa-head colonies)
What is the appearance of B. anthracis deep colonies?
Small, ragged, and stringy
What is the capsule of B. anthracis made of?
Polymers of D-glutamic acid and some polysaccharide
How long can B. anthracis spores remain viable?
More than 50 years
What factor of B. anthracis increases the intracellular cyclic AMP, causing edema
Edema Factor
What factor of B. anthracis binds to host cells and facilitates entry of EF and LF
Protective Antigen
What factor of B. anthracis damages and kills phagocytes, inhibits bactericidal activity of serum
Lethal Factor
What is the net effect of the B. anthracis toxin complex
Damage to phagocytes, increased capillary permeability, inhibition of clotting, and shock
What is the primary cause of death in animals infected with B. anthracis?
Extracellular toxin leading to shock and hemorrhage
What percentage of B. anthracis organisms are found in the blood at death?
80%
What percentage of B. anthracis organisms are found in the spleen at death?
20%
What are the major anthrax enzootic zones?
Tropics and subtropics (India, Pakistan, Africa, South America)
What are the environmental conditions favoring B. anthracis spore survival?
Alkaline soil, high nitrogen levels, alternating rain and drought, temperatures above 5.5°C
What is the localized form of anthrax in humans called?
Malignant carbuncle or pustule
What is the pulmonary form of anthrax called?
Woolsorter’s disease
What is the peracute form of anthrax characterized by?
Death within 1-2 hours
What is the acute form of anthrax characterized by?
Death within 24 hours
What is the localized form of anthrax in swine and dogs characterized by?
Pharyngeal involvement, gastroenteritis, and inflammatory edema of the head and neck
What is the primary route of infection for anthrax in humans?
Cutaneous (through wounds) or pulmonary (inhalation of spores)
What is the primary route of infection for anthrax in animals?
Ingestion of spores
What diagnostic stain is used to identify B. anthracis in tissues?
McFadyean’s stain (organisms appear blue, capsules appear pink)
What diagnostic test detects the capsular antigen of B. anthracis?
Agar gel precipitation test (Ascoli test)
What is the appearance of B. anthracis colonies on blood agar?
Non-hemolytic, ground glass-like (Medusa-head or judge’s wig-type colonies)
What is the component of “string of pearl” test for B. anthracis?
Penicillin
What bacteriophage is specific for B. anthracis
Gamma phage
What type of immunity do animals recover from anthrax have?
Permanent immunity
