Pathogens and Hosts Flashcards
What are the characterised signs and symptoms of clinical infection?
Inflammation Pain Raised body temp - pyrexia Rigors - body shaking violently Increased WBC Increased C reactive protein
What is a pathogen?
An organism which causes disease
What is a commensal?
An organism which is part of normal flora - doesn’t necessarily cause illness
Give an example of commensal
E.coli in the gut
What are the rules of Koch’s Postulates?
Organisms must be found in all cases of the disease
Must be able to be cultured outwith the body
Should reproduce the disease on inoculation
What is the pathogenicity of a micro- organism?
Its capacity to cause an infection
What are the requirements of pathogenicity?
Infectivity
Virulence
What is infectivity of a pathogen?
the ability to become established on or within a host
What is the virulence of a pathogen?
Its ability to cause harmful effect to the host once established
Do different strains of the same micro- organisms behave all the same?
No - different strains can behave very differently
What is the virulence specific to?
Strains not species
The harm that a pathogen causes is conferred by what/
Virulence factors
Where are exotoxins released?
Extracellularly by the micro-organism
Where do enterotoxins act on?
The GI tract
What are endotoxins structurally part of?
The gram negative cell wall
