Bacterial Pathogenicity Flashcards
Define the term “infective dose”
ID, amount of pathogen required to cause an infection in the host
Define “exotoxin”
A toxin released by a living bacterial cell into its surroundings
Define “endotoxin”
Toxins associated with the outer membrane of Gram- bacteria, refers to LPS
Define “toxoid”
Inactivated toxin useful for a vaccine
Give one example of an Overt / Strict pathogen
Neisseria gonorrhoeae
Define “Overt” or “Strict” pathogen
Only associated with human disease and are not found as members of the normal, healthy microbial flora
Define “Opportunistic” pathogen
Members of the normal flora that only cause disease when introduced into unprotected sites
Give one example of an Opportunistic pathogen
Pseudomonas aeuruginosa
What is the bacteria which causes Anthrax?
Bacillus anthracis
What is a “Virulence Factor”?
Molecules produced by micro-organisms to hep colonise, growth, spread in the host, and evade their system
How is flagella a virulence factor?
Allows motility, and can penetrate mucin and secrete mucinase
What is an Extracellular pathogen? Give an example
Pathogens which live outside the host cell, i.e. Streptococcus pneumoniae
What is an Intracellular pathogen? Give an example
Pathogens which live inside the host cell, i.e. Listeria monocytogenes, or Salmonella
Give 3 examples of Toxin producing bacteria
- Clostridium botulinum
- Clostridium tetani
- Escherichia coli O157:H7
Give 5 examples of Streptococcus pneumoniae virulence factors
- Capsule which prevents phagocytosis
- Surface adhesions attach to respiratory lining
- Secretory igA proteases to cleave igA
- Neuroaminidases to cleave neuraminic acids to use
- Pneumolysins to form pores
