lecture 1 - pathogenic strategies of bacteria

Question 1

what does a successful infection rely on

Answer 1

host

microbial factors

Question 2

what must a host try to do

Answer 2

restrict infection

Question 3

what is a TCS

Answer 3

two component system

Question 4

what is the TCS critical for

Answer 4

bacterial pathogenesis

Question 5

what is the bordetella pertussis (BP) Bvg TCS system

Answer 5

BP TCS is encoded by bvg locus

the sensor BvgS responds to environmental signals

BvgS autophosphorylates and then phosphorylates BvgA

BvgA bind operators of range of virulence genes (activates transcription of stuff)

Question 6

how many classes of genes expression is dependant on BvgA activity

Answer 6

4

Question 7

What does Bvg+ drive

Answer 7

Class 1 and 2 gene expression

respiratory tracts colonisation

Question 8

what does Bvgi drive

Answer 8

Class 3 gene expression

transmission

Question 9

what does Bvg- drive

Answer 9

Class 4 gene transmission

virulence repression

Question 10

what is bordetella pertussis

Answer 10

human pathogen

causative agent of pertussis (whooping cough)

Question 11

what are the facts about bordetella pertussis

Answer 11

small

gram negative rod

fastidious (require special conditions for growth)

Question 12

what is the infection course of whooping cough

Answer 12

1. incubation - aerosol transmission
2. catarrhal phase - runny nose, fever
3. paroxysmal phase - cough, vomiting
4. convalescence - vomiting or cyanosis

Question 13

what is Filamentous haemagglutinin (FHA)

Answer 13

a major adhesin for tracheal colonisation

Question 14

what does (FHA) do

Answer 14

binds sulphated polysaccharides e.g heparin

binds integrins on macrophages

Question 15

what does binding do and why is it essential

Answer 15

unregulated receptor expression

No binding means no biofilm formation

Question 16

what is the pertussis toxin

Answer 16

AB toxin

Question 17

what is Neisseria meningitidis

Answer 17

human pathogen

causative agent of invasive meningococcal disease

Question 18

what is an invasive disease

Answer 18

condition resulting in inflammation of protective membranes around brain and spinal cord

Question 19

what are the facts about Neisseria meningitidis

Answer 19

Small, GRAM NEGATIVE diplococcus

• Colonises nasopharynx and spread via droplets
• Correlation between CARRIAGE in teenagers and spread of bacteria

Question 20

what is the infection course of Neisseria meningitidis

Answer 20

colonisation - aerosol transmission

vascular dysfunction

thrombosis

inflammation

Question 21

what does Type IV do in micro colony formation

Answer 21

attach bacteria to vascular endothelial cells

Question 22

what does bacteria to vascular endothelial cells attachment help

Answer 22

bacteria resist shear stress and they replicate forming micro colonies

Question 23

what are important virulence factors

Answer 23

outer membrane proteins Opt and Opc

minor adhesins e.g NasA and App

Capsule

Question 24

where are the immune evasion mechanisms located

Answer 24

blood

lungs/brain

Question 25

how does temperature affect immune evasion mechanisms

Answer 25

host derived inflammation increases temperature

immune evasion mechanism is activated

Question 26

what is streptococcus pyogene

Answer 26

human pathogen

causative agent of nectrosiging fasciitis (NF)

Question 27

what is factors of streptococcus pyogenes

Answer 27

extremely high morbidity and mortality in humans

call gram positive coccus

air droplet transmission

Question 28

what does type 1 pilus do in adherence

Answer 28

binds range of host proteins and cells and different tip piling protein for each strain

Question 29

what is the two step dress of adherance

Answer 29

lipoteichoic acid binds first and then another adhesin e.g. m protein