Bacillus Anthracis Flashcards
What is septicemia?
Blood poisoning due to a large number of bacteria entering the bloodstream which should be sterile
Septicemia can lead to severe systemic infections and requires immediate medical attention.
Define zoonotic disease.
A pathogenic disease that has passed from non-human to humans
Zoonotic diseases can affect both animals and humans, often requiring public health interventions.
What does quiescence refer to?
A state of reversible dormancy or latency
Quiescence allows microorganisms to survive in unfavorable conditions.
What are haemorrhagic plural or peritoneal effusions?
Accumulation of bloody fluid in the pleural cavity or swelling in the abdomen caused by a build-up of fluid
These conditions can indicate serious underlying health issues.
Differentiate between polyclonal and monoclonal antitoxin antibodies.
Polyclonal antibodies are produced by multiple immune cells and bind to many epitopes; monoclonal antibodies are produced by identical immune cells and bind to specific epitopes
This distinction is crucial for therapeutic applications and diagnostics.
What is a phagosome?
Phagosomes play a key role in the immune response by engulfing pathogens, forming a vesicle around it to destroy in phagocytosis
Describe the phenotypic characteristics of Bacillus anthracis.
Gram positive, facultative anaerobe, rod shaped, poly D glutamic acid capsule, forms single spore
These characteristics help in identifying B. anthracis in laboratory settings.
What are the three principal forms of human anthrax?
Cutaneous, inhalational (respiratory disease- leading to septicaemia), ingestion (oropharyngitis or gastro enteritis)
Each form presents different clinical manifestations and requires specific diagnostic and treatment approaches.
What are the virulence plasmids expressed by Bacillus anthracis?
Two virulence plasmids: pOX1 (encoding Lethal Factor and Oedema Factor with Protective Antigen) and pOX2 (encodes the capsule operon capBCADE)
These plasmids are crucial for the pathogenicity of B. anthracis.
How is suspected cutaneous anthrax diagnosed?
Sampling of suspect skin, confirm by laboratory testing:
Blood or bodily fluid can be stained staining polychrome methylene blue
Colonial morphology - white to cream colonies non haemolytic and non motile, penicillin & gamma phage sensitive on blood or nutrient agar.
Laboratory confirmation is essential to distinguish anthrax from other skin infections.
Which genes are targeted when using PCR to confirm B. anthracis?
Sequences targeting Lethal Factor and Protective Antigen genes on pXO1
These targets provide specificity for diagnosing anthrax.
What is the primary treatment for systemic infections caused by B. anthracis?
Antibiotics, typically doxycycline, ciprofloxacin, and penicillin
Early administration of antibiotics is critical for effective treatment.
Which type of antimicrobials are least effective against B. anthracis strains?
Poor sensitivity to extended spectrum cephalosporin and trimethoprim-potentiated sulphonamides
Understanding antimicrobial resistance patterns is important for effective treatment planning.
What are the virulence factors elicited by Bacillus anthracis?
PA complexes on host cell membrane allowing LF & EF to bind after endocytosis. The LF and EF are taken into the cytosol of the cell using PA.
LF is a zinc metalloproteinase which acts to suppress immune functions including phagocytosis.
EF is an adenylyl cyclase which again supresses immune cells functions.
Fill in the blank: The capsule of Bacillus anthracis inhibits _______.
Phagocytosis
This ability to evade immune response contributes to the virulence of the bacteria.
