Microbial pathogenisis Flashcards
1
Q
def. pathogenicity
A
ability of microbe to cause disease
2
Q
def. virulence
A
traits that render micorbes pathogenic
3
Q
2 general divisions of virulence
A
- invasion
2. host damage
4
Q
4 virulence factors involving invasion
A
- portal of entry
- surface colonization
- surviving host defences
- portal of exit - transmission to new host
5
Q
3 main sites of entry
A
- skin - reuires break
- mucosa
- transplants
6
Q
2 ways to surface colonize
A
- adhesins - fimbriae, capsues
2. bind to receptors of host and transcytosis
7
Q
2 general classes of host defences
A
- non-specific
2. specific
8
Q
3 types of non-specific host defences
A
- barriers
- complement
- phago
9
Q
2 specific host defences
A
- antibody mediated
2. cell-mediated
10
Q
ways to survive complement (2)
A
- surface proteins that bind/inhibit complement
2. capsules and biofilms that mask activating substances
11
Q
3 ways to survive phago
A
- capsules and biofilms so no access
- exotoxins kill neutrophils and macros
- intracellular survival
12
Q
6 ways to survive specific defences
A
- immunosupression (HIV)
- diversion of lymphocyes function - superantigens
- antigenic variation - change surface antigens
- proteolysis of ABs - extracellular proteases
- prevnt opsinization - bind the Fc portions
- viral latency
13
Q
5 modes of transmission
A
- contact (direct or indirect)
- droplet
- airborne
- vector borne
- common vehicle
14
Q
4 general ways a microbe causes damage
A
- due to host response
- toxins
- apoptosis
- mechanical causes
15
Q
potential problems from host reponse
A
- inflammation - prostattis
- rheumatic fever
- complement - septic shock
