Bacillus anthracis
From IDWiki
Background
Microbiology
- Gram-positive bacillus that is distinguished from other Bacillus by being non-motile and non-hemolytic
- Colonies are gray, flat, and may have a "Medusa head" or "comet" appearance
- The main toxin has subunits A and B
- A subunit may be either EF (edema factor) or LF (lethal factor)
- B subunit is the protective antigen, against which antibodies react
- Lives in soil
- Wild and farm animals that have contact with contaminated soil is a common exposure, including to wool and animal hides
- Can also be acquired by inhalation of spores
Clinical Manifestations
Cutaneous Anthrax
- Caused by inoculation of spores into soft tissue
- Incubation period of 2 to 5 days
- Lesion develops at site of inoculation, starting as erythemaous papule, then ulceration, then eschar
- May progress to sepsis
Pulmonary Anthrax
- Caused by inhalation of spores
- Also known as woolsorter's disease
- Start with malaise, fever, and nonproductive cough, followed by respiratory distress, severe pulmonary edema, and death
Gastrointestinal Anthrax
- Caused by ingestion of spores
- Infects oropharynx or abdomen
- Causes sepsis