POM 10 - Activities of a pathogen 2 Flashcards
what are the 4 components of virulence factors
adherence
invasion
immune evasion
toxins
what are virulence factors
the genetic determinants that allow a pathogen to cause disease
explain the virulence factor of adherence
ability to interact or bind with humor cell
explain the virulence factor of invasion
factors that enable bacteria to find a new niche
explain the virulence factor of immune evasion
avoidance of innate immune system
most important factor
explain the virulence factor of toxins
bacteria release to damage neighboring cells
what is the most important virulence factor
immuen evasion
what is virulence
the ability to cause disease in hosts with intact defences
what does virulence require
some breech of host defences
what is pyrogenic infection - what are the 3 parts to it
tissue invasion, multiplication, and immune response in sterile site
what is granulomatous/chronic infection - what part of the immune system does it evade and what cells are activated to respond to this infection
evade innate immune system
activated macrophages fuse and surround the antigen
incomplete host response = granuloma
what is bacterial intoxication
change in host physiology and tissue destruction
how does cholera cause an infection at a cellular level - 4 steps
infection with vibrio cholerae
cholera divides in bowel and releases a toxin which inhibits GTPase enzyme
cGMP builds up inside cell and causes cell membrane pump to pump Cl- ions out of cell
Cl- Na+ and water is lost in bowel = profuse diarrhoea
what happens at the start of appendicitis
appendix is obstructed with a faecolith
bacteria propogate
how does the bacteria affect the appendix in appendicitis at the cellular level
bacteria interact with cells lining the appendix
bacteria damages cells via toxins/cytolysins