bacterial pathogenicity L5

Question 1

pathogen=

Answer 1

organism capable of causing disease

Question 2

disease=

Answer 2

clinical signs and symptoms of damage that occurs in a host as a result of its interaction with an infectious agent

Question 3

Koch’s postulates=

Answer 3

after isolation a laboratory culture of an organism should both initiate the disease and be recovered from the diseased animal

Question 4

microbe free areas of the body=

Answer 4

fluids

tissues/organs

Question 5

3 host facts that effect whether infection occurs

Answer 5

immune status
prior exposure
genetic predisposition

Question 6

4 bacteria facts that effect whether infection occurs

Answer 6

site of infection
route of inoculum
site of inoculum
specific traits of bacterial strain

Question 7

what is an overt or strict pathogen

Answer 7

only associated with human disease

not part of normal healthy flora

Question 8

what are opportunistic pathogens

Answer 8

members of the normal flora that only cause disease when introduced into unprotected sites

Question 9

what are Facultative pathogens

Answer 9

can grow and survive in environment as well as host

Question 10

what can help bacteria establish an infection

Answer 10

virulence factors

Question 11

what do bacterial virulence factors facilitate

Answer 11

colonisation, growth and spread in host, evasion of the host immune system

Question 12

examples of virulence factors (5)

Answer 12

adhesions 
flagella
factors that help obtain essential nutrients
Toxins 
capsule

Question 13

bacterial strategies of pathogenesis (3)

Answer 13

extracellular pathogen
toxin producing pathogens
intracellular pathogens

Question 14

what type of bacteria is streptococcus pneumonia

Answer 14

Gram + cocci

Question 15

where is streptococcus highly invasive

Answer 15

lung tissue

Question 16

what causes the symptoms of pneumonia

Answer 16

hosts immune system

Question 17

what is an endotoxin the colloquial name for

Answer 17

Lipopolysaccharide of Gr- bacteria

Question 18

general symptoms of endotoxins =

Answer 18

fever
diarrhoea
vomiting

Question 19

e.g of toxin producing pathogen (extracellular)

Answer 19

clostridium botulinum

Question 20

upon detection of bacterial LPS (endotoxins) what is delivered to endosomes

Answer 20

TLR4 (toll-like receptor 4)

Question 21

what are exotoxins

Answer 21

proteins released extracellularly

Question 22

2 facts about exotoxins

Answer 22

generally destroyed by heat
specific targets (highly toxic)

Question 23

enterotoxin=

Answer 23

the group of exotoxins that act on the small intestine

Question 24

examples of 3 toxins produced by pathogens

Answer 24

Beta-haemolysin
botulinum toxin
cholera toxin

Question 25

what produces beta-haemolysin

Answer 25

streptococcus pyogenes Gr+

Question 26

what does beta-haemolysin cause

Answer 26

complete break down of haemoglobin

Question 27

what produces botulinum toxin

Answer 27

Clostridum botulinum

Question 28

what does Clostridum botulinum form that helps bacteria survive and reproduce

Answer 28

Spores

Question 29

most potent toxin known to man=

Answer 29

botulinum toxin

Question 30

botulinum toxin causes

Answer 30

flaccid paralysis

Question 31

cholera toxin=

Answer 31

an exotoxin

Question 32

e.g of intracellular pathogen

Answer 32

salmonella enterica serovar typhimurium

Question 33

what pathogen can escape vacuole and live in cytoplasm

Answer 33

listeria monoctyogenes

Question 34

where is listeria monocytogenes found

Answer 34

soft cheese, pate, raw vegetables

Question 35

people at risk of listeria monocytogenes

Answer 35

pregnant women
immuno-compromised
leukemia

Question 36

what bad disease can listeria monocytogenes lead to

Answer 36

meningitis

Question 37

4 strategies for immune evasion

Answer 37

1. hiding inside cell
2. phase variation /antigenic variation
3. molecular mimicry
4. modifying or block host immune response

Question 38

what is antigenic variation and phase variation

Answer 38

bacteria change immunogenicity at high frequency avoiding an established immune response

Question 39

molecular mimicry=

Answer 39

bacteria pretend to be host by putting host antigens on their surface

Question 40

what can molecular mimicry also cause

Answer 40

can trigger immune response against autoantigens

Question 41

e.g of an autoimmune response caused by molecular mimicry

Answer 41

rheumatic heart disease

Question 42

3 examples of modifying/blocking the host immune response

Answer 42

1. capsule interfere with phagocytosis
2. IgA protease against antibody
3. interfere with host’s cell signalling pathways

Question 43

black holes in pathogens=

Answer 43

deleted information

Question 44

pathogenicity islands=

Answer 44

extra information

Question 45

3 genetic processes virulence factors might be associated with

Answer 45

1. black holes
2. pathogenicity islands
3. plasmids, transposons (jumping gene), bacteriophage

Question 46

what causes such variance in how toxic ecoli is

Answer 46

pathogenicity islands

Question 47

is vibrio cholerae gram - or gram +

Answer 47

gram negative

Question 48

is clostridium botulinum gram -/+

Answer 48

gram positive (spore former)

Question 49

is salmonella gram -/+

Answer 49

gram negative

Question 50

is listeria monocytogenes gram +/-

Answer 50

gram + rod