Pathogens and host intro Flashcards
What are the possible signs and symptoms for clinical infection?
Inflammation Pain Pyrexia Tachycardia Rigors Increased white blood cell count Increased C reactive protein count
What is a commensal?
An organism that is part of the normal flora
What does the capacity of a microorganism to cause infection depend on?
Infectivity
Virulence (harmful effects once established)
What factors affect infectivity?
Attachment
Acid resistance
What factors affect virulence?
Invasiveness
Toxin production
Evasion of immune system
Define cellulitits
Inflammation of subcutaneous connective tissue
Define necrotising fasciitis
Disease - fasciae of muscles and other organs becomes inflamed and results in the destruction of the overlying tissue
What enzymes can result in connective tissue breakdown?
Hyaluronidase
Collagenase
Define fibrinolysis
The enzymatic breakdown of fibrin in blood clots
Streptokinase
What are exotoxins
Released extracellularly by the micro-organism (tetanus)
What are enterotoxins?
Exotoxins which act on the GI tract
What is endotoxin
Part of the gram negative cell wall
Which organism produces tetasnospasmin the causative agent of tetanus?
Clostridium tetani
How does tetasnospasmin work?
Binds to nerve synapses and prevents the release of inhibitory neurotransmitters
Give an example of a bacteria that produces an enterotoxin
Vibrio Cholera
