Genus Bacillus. B. anthracis

• What is the Gram stain classification of the genus Bacillus?

  Gram +ve
• What types of oxygen requirements do Bacillus species have?

  Strict aerobes and facultative anaerobes
• How do Bacillus spores form?

  Spores form inside the cells
• What is the typical habitat of Bacillus species?

  Widespread in water and soil
• Which Bacillus species are considered the most important?

  Bacillus Anthracis and Bacillus Cerus
• What is the shape of Bacillus Anthracis cells?

  Bamboo stick-shaped
• What unique feature do Bacillus Anthracis colonies exhibit?

  Halo of projections (Medusa head)
• Does Bacillus Anthracis have flagella?

  No flagella
• What type of capsule does Bacillus Anthracis have?

  Protein capsule (poly-D-glutamate)
• What type of anaerobe is Bacillus Anthracis?

  Facultative anaerobe
• Is Bacillus Anthracis fastidious or non-fastidious?

  Non-fastidious
• What types of colonies does Bacillus Anthracis produce?

  Virulent R colonies and avirulent S colonies
• What carbohydrates can Bacillus Anthracis ferment?

  Glucose, Maltose, Saccharose, and Starch
• What are the indole and urease test results for Bacillus Anthracis?

  Indol and Urease Negative
• What are the reservoirs for Bacillus Anthracis?

  Soil and mammals
• How does human infection with Bacillus Anthracis occur?

  Through exposure to B. anthracis or its spores
• What are common sources of exposure to Bacillus Anthracis?

  Infected animals or animal products
• What is a potential method of bioterrorism involving Bacillus Anthracis?

  Exposure to weaponized B. anthracis spores
• What is the role of the polysaccharide capsule in Bacillus Anthracis?

  Antiphagocytic
• What is the anthrax toxin composed of?

  A and B subunits
• What are the components of the A subunits of anthrax toxin?

  Oedema Factor and Lethal Factor
• What is the function of the Oedema Factor in anthrax toxin?

  Increases cAMP leading to cell oedema
• What does the Lethal Factor do in anthrax toxin?

  Cleaves map kinase causing tissue necrosis
• What is the role of the B subunit (PA) in anthrax toxin?

  Facilitates entry of A subunit into host cell
• What is a characteristic skin lesion of anthrax?

  Black Eschar
• What are the three subtypes of anthrax?

  Cutaneous, Inhalation, and Gastrointestinal
• What is the incubation period for cutaneous anthrax?

  5-7 days
• What is the typical presentation of cutaneous anthrax?

  Boil-like skin lesion leading to black eschar
• What percentage of cutaneous anthrax cases may lead to toxaemia and death?

  20%
• What is the incubation period for inhalation anthrax?

  1-3 days
• What are the symptoms during the prodromal phase of inhalation anthrax?

  Non-specific flu-like symptoms
• What are the symptoms during the fulminant phase of inhalation anthrax?

  Shock, hypoxia, and high-grade fever
• What is a significant radiological finding in inhalation anthrax?

  Mediastinal widening due to haemorrhagic mediastinitis
• What is a common feature present in all three types of anthrax?

  Local/regional lymphadenopathy
• How do spores of Bacillus Anthracis behave in the body?

  Germinate into active bacilli in lymph nodes
• What happens to bacilli after they multiply in macrophages?

  They burst macrophages, releasing more bacilli
• What is the microbiological diagnosis method for Bacillus Anthracis?

  Gram staining and capsule staining
• What specimens are used for diagnosing Bacillus Anthracis?

  Secretions, blood, and CSF
• What is the procedure for capsule staining of Bacillus Anthracis?

  Use methylene blue and carbol fuchsin
• What is the procedure for spore staining of Bacillus Anthracis?

  Use carbol fuchsin and acidified ethanol