Week 16

Question 1

Define bacteraemia

Answer 1

Spread of infection to distant organs

Question 2

What does hematogenous spread mean?

Answer 2

The route of spread is blood.

Question 3

Define septicaemia

Answer 3

Presence of bacteria/ toxins in the blood

Question 4

What are some symptoms of sepsis?

Answer 4

Hi HR
hi respiration rate
Hi fever
Lo BP

Question 5

Why does septic shock produce blood spots under the skin?

Answer 5

Blood coagulates under the skin as the vasculature breaks down

Question 6

What is meningitis?

Answer 6

Inflammation of the meningeal (membranes lining the brain and spinal cord)

Question 7

What is the most common pathogen type that causes meningitis? (viral, bacterial, fungal)

Answer 7

Virus

Question 8

What do Kernig’s or Brudzinki’s signs involve?

Answer 8

Stretching hamstrings or hip flexors to see if neck is super stiff or if any pain is felt

Question 9

What bacterial infection causes most of otitis media, sinusitis, lung infections, endocardium and meninges?

Answer 9

strept. pneumoniae

Question 10

What gram is strept. pneumoniae?

Answer 10

Gram +ve

Question 11

What kind of hemolytic is strept. pneumoniae?

Answer 11

alpha hemolytic

Question 12

What is the most common vaccine for strept. pneumoniae?

Answer 12

Prevnar 13

Question 13

What are the two main virulence factors of strept. pneumoniae?

Answer 13

a) pneumolysin damages lungs
b) H2O2 damages lungs and is produced by strept. pneumoniae

Question 14

What is the basis for vaccines for strept. pneumoniae?

Answer 14

Capsular polysaccharide

Question 15

What are the main bacterial cause of meningitis?

Answer 15

Strept. pneumoniae
Neisseria meningitidis

Question 16

Is Neisseria meningitidis non capsulated or capsulated?

Answer 16

Capsulated

Question 17

What gram is Neisseria meningitidis?

Answer 17

-ve

Question 18

What’s the difference between endemic and epidemic?

Answer 18

endemic= infection maintained in population

epidemic= rate that exceeds ‘expected’

Question 19

Why is the highest infection rate for Neisseria meningitidis at 6-7 months?

Answer 19

Passive maternal antibodies decline before the child’s immune system matures

Question 20

What are the 5 main virulence factors for Neisseria meningitidis?

Answer 20

IgA protease
Pili- receptor specific attachment to nasopharynx
OMPs- closer interactions/ invasions
LPS
capsule=antiphagocytic

Question 21

What causes the rash that doesn’t go away under glass?

Answer 21

meningococcal septicaemia

Question 22

Where do extracellular bacterial pathogens reside?

Answer 22

Blood vessels
Lymphnodes
epithelial surface

Question 23

Where do intracellular bacterial pathogens reside?

Answer 23

Cytoplasm
organelles

Question 24

What are the two types of Intracellular bacterial pathogens?

Answer 24

Obligate-rely on host for primary metabolites

Faculative-can replicate in the absence of the host

Question 25

Is Chlamydia an obligate or faculative pathogen?

Answer 25

Obligate

Question 26

Is E.coli an obligate or faculative pathogen?

Answer 26

Faculative

Question 27

Name some pros of intracellular living for a bacterial pathogen?

Answer 27

-evades immune response -nutrients -homeostasis

Question 28

Name some cons of intracellular living for a bacterial pathogen?

Answer 28

-needs to enter host cell -needs to escape the host to continue infection

Question 29

What are the three methods to survive a macrophage?

Answer 29

1) ESCAPE= secrete exotoxins, disrupt phagosomal membrane 2) STAND+FIGHT=protective film and lo pH dependent replication 3)DODGE= prevent vacuole/ lysosome fusion

Question 30

What pathogens use the ESCAPE method to survive macrophages?

Answer 30

Rickettsia Shigella

Question 31

What pathogens use the STAND+FIGHT method to survive macrophages?

Answer 31

Salmonella MBT Coxiella

Question 32

What pathogens use the DODGE method to survive macrophages?

Answer 32

Chlamydia

Question 33

How does shigella invade GI cells?

Answer 33

1) initial entry at Mcells 2)transfer to macrophages and epithelial 3)induces phagocytosis via disruption of actin cytoskeleton (membrane ruffles) 4) intracellular pathogens subvert normal cell function

Question 34

What are the roles of M cells in the GI tract?

Answer 34

They sample the lumen of the GI to prep the lymphatic system

Question 35

Via what adhesin does UPEC bind?

Answer 35

Dr adhesin bind to CEACAM

Question 36

What are the 5 exit sttrategies for an intracellular bacterial pathogen?

Answer 36

1) Remodel actin cytoskeleton 2) Degrade the cell membrane 3) trigger apoptosis 4) trigger pyroptosis (same as apoptosis but with inflammation) 5) Extrusion

Question 37

Is rickettsia obligate or faculative?

Answer 37

Obligate

Question 38

What is interesting about the Rickettsia genome?

Answer 38

Small, degraded genome Quite similar to human mitochondria

Question 39

What causes rocky mountain fever?

Answer 39

R. rickettsia

Question 40

What does rocky mountain fever look like?

Answer 40

Rash, swelling and fluid leakage (ticks)

Question 41

What species of rickettsia is transmitted by body louse?

Answer 41

R. prowazeckii

Question 42

Where does rickettsia replicate?

Answer 42

Endothelial cells of primary vasculature causing vasculitis

Question 43

What serotype of chlamydia causes eye disease?

Answer 43

Trachoma

Question 44

What are the symptoms of Trachoma?

Answer 44

Edge of eyelid is pulled inwards, eyelashes scrape and cause scarring of the cornea

Question 45

What gram is chlamydia?

Answer 45

-ve

Question 46

What is weird about chlamydia cell wall?

Answer 46

Very little peptidoglycan present, but it's essential for cell replication so penicilin still works

Question 47

Describe the chlamydia life style

Answer 47

1) elementary bodies enter through abrasions on mucosal surfaces 2)Endocytosis/actin remodelling 3) differentiation into reticulate body 4) multiplication of elementary bodies and release t o spread infection