MICR102A - Bacillus

these organisms are mostly non-pathogenic and saprophytic.

bacillus

what is the most pathogenic bacillus specie? that is characteristically large, rod-shaped, and gram (+) measuring approximately 1 µm x 3–6 µm.

b. anthracis

refers to an organism that feeds on dead or decaying organic matter.

saprophytic

bacillus anthracis causes?

anthrax

anthrax in german is called?

Milzbrand

anthrax is also called ______ in french

Charbon

what animals are susceptible to anthrax?

herbivores

true or false

anthrax is highly fatal to humans

true

what animals are resistant to anthrax?

carnivores and avians

what is the shape and gram reaction of Bacillus anthracis?

large gram-positive rods

what unique feature encloses chains of Bacillus anthracis?

single capsule

where does spore formation occur best?

a. 5-10°C

b. 15-40°C

c. 50-70°C

d. Above 100°C

b. 15-40°C

true or false:

the spores of Bacillus anthracis are swollen and terminal.

false. (They are central to subterminal and not swollen.)

what is the characteristic colony appearance of Bacillus anthracis?

ground glass-like with irregular "medusa-head" margins

what is the capsule of Bacillus anthracis made of?

d-glutamic acid

what are favorable environmental conditions for bacillus anthracis?

a. acidic soil, low nitrogen, cold temperature

b. alkaline soil, high nitrogen, alternating rain & drought

c. wet, marshy areas with low oxygen

d. high humidity and low temperatures

b. alkaline soil, high nitrogen, alternating rain & drought

what are the main sources of bacillus anthracis infection? (list at least three.)

soil, bone meal, wool, hair, tannery effluents, bloodsucking flies, and carrion eaters (scavenger animals)

true or false

bacillus anthracis spores can remain viable in the environment for over 50 years.

true

what is the primary route of infection for anthrax in animals?

a. direct contact with infected blood

b. ingestion or inhalation of spores

c. bite from infected animals

d. skin wounds

b. ingestion or inhalation of spores

what organ plays a key role in clearing bacillus anthracis from the bloodstream?

spleen

major anthrax enzootic zones in tropics and subtropics countries such as (4)

India, Pakistan, Africa, South America

what are the three components of anthrax toxin?

edema factor (ef), protective antigen (pa), lethal factor (lf)

which anthrax toxin component increases intracellular camp?

edema factor (ef)

which anthrax toxin component binds receptors and enables ef & lf action?

protective antigen (pa)

which anthrax toxin component disrupts cellular signaling?

lethal factor (lf)

true or false

the anthrax toxin contributes to shock and reduced phagocytosis.

true

what is the most common form of anthrax in humans?

a. cutaneous anthrax

b. pulmonary anthrax

c. gastrointestinal anthrax

d. bloodborne anthrax

a. cutaneous anthrax

true or false:

inhalation anthrax (woolsorter’s disease) is typically mild and self-limiting.

false. (it is highly fatal.)

what are the two timeframes for anthrax progression?

- peracute: 1-2 hours

- acute: less than 24 hours

which staining technique is used to detect the capsule of bacillus anthracis?

a. ziehl-neelsen stain

b. mcfadyean's stain

c. india ink stain

d. gram stain

b. mcfadyean's stain

what color do bacillus anthracis organisms appear in mcfadyean's stain?

blue organisms with pink capsules

what laboratory test detects the capsular antigen of bacillus anthracis?

ascoli test (agpt)

true or false:

bacillus anthracis forms hemolytic colonies on blood agar.

false (it is non-hemolytic.)

what test causes bacillus anthracis cells to swell into pearl-like structures when exposed to penicillin?

string of pearl test

which vaccine is used for bacillus anthracis prevention?

a. bcg vaccine

b. pasteur's killed anthrax vaccine

c. sterne's live, non-capsulated spore vaccine

d. live attenuated mlv vaccine

c. sterne's live, non-capsulated spore vaccine

true or false

animals that recover from anthrax develop permanent immunity.

true

what is the standard method for destroying bacillus anthracis spores?

autoclaving

true or false:

anthrax is a reportable disease that requires strict control measures.

true