Pathogens and host intro Flashcards
What are the possible signs and symptoms for clinical infection?
Tachycardia
Rigors- cold,sweaty,with increased temperature
Inflammation
Increased white blood cell count
Increased C reactive protein count
Pyrexia- fever
Pain
What is a pathogen
Organism which can cause disease
What is a commensal?
An organism that is part of the normal flora
The capacity of a microorganism to cause infection depends on what?
Infectivity- ability to become established
Virulence- capacity to cause harm
What factors affect infectivity?
Attachment
Acid resistance
What factors affect virulence?
Toxin production
Invasiveness
Evasion of immune system
Define cellulitis
Inflammation of subcutaneous connective tissue
Define necrotising fasciitis
Disease - fasciae of muscles and other organs becomes inflamed
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-dissolves blood clot
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
Induces uncontrolled host response
Which organism produces tetasnospasmin the causative agent of tetanus?
Clostridium tetani
Give an example of a bacteria that produces an enterotoxin
Vibrio Cholera
