bacterial pathogenesis

Question 1

pathogen

Answer 1

microbe that harms the host/causes disease

Question 2

commensal

Answer 2

microbe that does not cause harm

Question 3

saprophyte

Answer 3

feeds on and decomposes dead organic material

Question 4

infection

Answer 4

colonisation of host by micro-organisms that have the potential to cause disease

Question 5

pathogenesis

Answer 5

biological mechanisms that lead to the diseased state

Question 6

virulence

Answer 6

ability of pathogen to cause disease in host

Question 7

opportunistic pathogen

Answer 7

can be part of normal flora but may be harmful if they move from part of body to another

Question 8

strict pathogen

Answer 8

always associated with disease

Question 9

2 major components of bacterial pathogenesis

Answer 9

bacterial virulence factors that damage or alter host cells and tissues
host response

Question 10

steps to bacterial pathogenesis

Answer 10

exposure
adherence to skin/mucosa
invasion through epithelium
colonisation and growth - production of virulence factors - invasiveness
additional virulence factor interactions with host molecules
tissue damage, disease

Question 11

pathogen determinants

Answer 11

virulence
environmental stability
route of entry
infective dose
tissue tropism
susceptibility to host defence

Question 12

host determinants

Answer 12

species
age
breed
sex
genetic factors
physiological factors
immune competence

Question 13

what are virulence factors

Answer 13

mechanisms/products of pathogens that promote their ability to cause infection and disease

Question 14

2 types of virulence factors

Answer 14

factors promoting colonisation/invasion of host
factors causing damage to host

Question 15

secreted virulence factors

Answer 15

coagulase - clots plasma - protecting host defences
proteases - degrade protein
nucleases - degrade nucleic acids
leukocidins - kill leukocytes
haemolysins - cause anaemia