Bacillus anthracis - MegaMicro

i. Encapsulated

ii. Gram Positive Rod

i. Spore forming

ii. Facultative anaerobe

iii. Virulence factors

1. Protective antigen

2. Edema factor (EF) –  adenylate cyclase activity  ↑[cAMP]  edema and inhibition of polymorphonuclear leukocytes

a. Likely responsible for characteristic edematous borders of black eschar in cutaneous anthrax

3. Lethal Factor (LF) – protease  Cell Death

4. Toxins (Combination of above factors):

a. Edema Toxin – PA + EF

b. Lethal Toxin – PA + LF

5. Capsule – contains poly-D-glutamic acid (i.e. protein)

i. Reservoir – herbivores

ii. Spores were delivered in mail in 2001 (i.e. “2001 Anthrax Attacks”)

iii. Spread to humans via inoculation, ingestion, inhalation

i. Microscopy

1. Spores – view with spore strain, incubated with low CO2

2. Non-hemolytic

3. Non-motile

ii. PCR

i. Manifestations

1. Cutaneous anthrax

a. Painless papule, develop to ulcer and necrotic, black eschar

b. Lymphadenopathy, edema

2. Gastrointestinal anthrax

a. Ulcers in mouth/esophagus

b. Nausea, vomiting, malaise

3. Inhalation anthrax

a. Prolonged latent period (spores)

b. First stage: Fever, myalgias, non-productive cough, malaise

c. Second stage: Fever, edema, enlargement of mediastinal lymph nodes

d. Meningeal symptoms

ii. Therapy

1. Current treatment: ciprofloxacin or doxycycline, combined with 1 or 2 additional antibiotics

2. Penicillin resistance is observed

a. If not resistant, use of Penicillin G (parenterally) is sufficient

iii. Prevention and control

1. Vaccination available, although less effective

2. Recommendation -  vaccination of animal herds