II-A. Systemic Bacteriology | 19. Bacillus genus Flashcards
I. Bacillus genus
1. What are the features of Bacillus genus?
- Gram-positive, spore forming rods
- usually seen in chains
- endospore formation (helps the survival of the bacterium)
- easy to culture
I. Bacillus genus
2. What are the 2 important species of Bacillus genus
- Bacillus anthracis
- Bacillus cereus
I. Bacillus genus - Bacillus anthracis
3A. What are the virulence factors of Bacillus anthracis?
- capsule (synthesizing enzymes are encoded on plasmid)
- AB-type toxins (encoded on plasmid)
I. Bacillus genus - Bacillus anthracis
3B. What are the features of capsule as a virulence factor?
capsule (synthesizing enzymes are encoded on plasmid)
* it is NOT a polysaccharide!
* D-glutamate polymer (aminoacid!)
* antiphagocytic
I. Bacillus genus - Bacillus anthracis
3C. What are the features of AB-type toxins as a virulence factor?
AB-type toxins (encoded on plasmid)
* edema factor (A subunit)
* lethal factor (A subunit)
* protective antigen (B subunit)
I. Bacillus genus - Bacillus anthracis
4. What is the source of infection of Bacillus anthracis ?
- zoonotic disease (animal products)
- contaminated environment (soil)
I. Bacillus genus - Bacillus anthracis
5. What is the transmission route of Bacillus anthracis ?
- consumption of contaminated animal products
- inhalation of environmental spores
- direct contact (through skin injuries)
I. Bacillus genus - Bacillus anthracis
6A. What are the 4 diseases caused by Bacillus anthracis?
- cutaneous anthrax
- gastrointestinal anthrax
- pulmonary anthrax
- injection anthrax
I. Bacillus genus
6B. What are the features of cutaneous anthrax?
- non-painful ulcer with marginal edema
- might disseminate and lead to blood stream infection later
I. Bacillus genus
6C. What are the features of gastrointestinal anthrax?
- bowel ulcerations
- haemorrhagic diarrhoea
- necrosis of bowels
- consequent blood stream infection
I. Bacillus genus
6D. What are the features of pulmonary anthrax?
- haemorrhagic pneumonia
- necrosis of lung tissue
- consequent blood stream infection, respiratory failure
I. Bacillus genus
6E. What are the features of injection anthrax?
in recent years in heroin-injecting drug users in northern Europe
I. Bacillus genus - Bacillus anthracis
7A. How can we diagnose diseases caused by Bacillus anthracis?
I. Bacillus genus - Bacillus anthracis
7B. How can we do sampling for diseases caused by Bacillus anthracis?
sampling: based on clinical disease
* skin anthrax: ulcer biopsy
* systemic symptoms: blood culture
* pneumonia: sputum / BAL
* GI anthrax: stool
I. Bacillus genus - Bacillus anthracis
7B. How can we do laboratory for diseases caused by Bacillus anthracis?
- culturing (non-haemolytic on blood agar!)
- IF, PCR