export_upper respiratory pathogens i

Question 1

Components of the URT

Answer 1

Conjunctiva
Nasolacrimal ducts

Middle ear

Nose

Pharynx

Sinuses/nasal cavity

Larynx

Epiglottis

Question 2

Where does bacteria end up in the URT

Answer 2

Trachea or terminal airway

Question 3

Where do viruses end up in the URT

Answer 3

Terminal airway and alveoli

Potentially suspended in air

Question 4

Sterile URT tissues

Answer 4

Mastoid air cells
Middle ear

Sinuses

Trachea

Bronchi and bronchioles

Alveoli

Question 5

Describe the sterility of the conjunctiva

Answer 5

It’s supposed to be sterile, but because of its location it is exposed to many organisms
Colonization is really uncommon, so it’s still considered sterile

Question 6

Normal flora of the nose

Answer 6

Staphylococcus epidermis
Staphylococcus aureus

Corynebacterium spp.

Question 7

Clinical relevance of Staph. aureus

Answer 7

About 20% of people have this in the normal population

People in hospitals have a higher percentage

Question 8

Staph. epidermis features

Answer 8

Gram positive cocci clusters

Facultative anaerobes

Question 9

Staph. aureus features

Answer 9

Gram positive cocci clusters

Facultative anaerobes

Question 10

Corynebacterium spp. features

Answer 10

Gram positive rod
Pleomorphic

Non-spore forming

Question 11

Nasopharynx normal flora

Answer 11

Streptococcus
Moraxella catarrhalis

Bacteroides

Question 12

Bacteria in the Strep. viridans group

Answer 12

S. mutans
S. mitis

S. milleri

S. salivarius

Question 13

Strep. viridans features

Answer 13

Gram positive cocci chains

Question 14

Moraxella catarrhalis features

Answer 14

Gram negative diploid-coccobacillus

Aerobic

Question 15

Bacteroides features

Answer 15

Strict anaerobe

Only if someone’s anatomy allows for oxygen-free pockets

Question 16

URT pathogens with seasonal association

Answer 16

Strep. pneumoniae
Haemophilus influenzae

Neisseria meningitides

Moraxella catarrhalis

Question 17

What differentiates Strep. from Staph.?

Answer 17

Strep. is catalase negative

Question 18

Strep. A

Answer 18

S. pyogenes

Beta-hemolytic

Question 19

Strep. B

Answer 19

S. agalactiae

Beta-hemolytic

Question 20

Strep. D

Answer 20

S. bovis
Not hemolytic

Enterococcus facaelis also included in this group, though it is no longer considered a Strep.

Question 21

Which Strep. group is alpha-hemolytic?

Answer 21

S. pneumoniae

Question 22

Streptococcal pharyngitis

Answer 22

Streptococcus pyogenes

Differentiated by beta-hemolysis

Question 23

S. pyogenes components

Answer 23

M protein

Capsule

Question 24

M protein

Answer 24

Essential for virulence
Antiphagocytic

80 serotypes, not cross protective

Question 25

Capsule

Answer 25

Inhibits phagocytosis | Also a virulence factor, but not found in all strains

Question 26

Streptococcal pyrogenic exotoxins

Answer 26

Found in S. pyogenes Super Ags SPE-A, B, C, etc. (9 total)

Question 27

SPE effects on body

Answer 27

Fever Rash T-cell proliferation B-cell suppression

Question 28

SPE diseases

Answer 28

Scarlet fever Toxic shock Necrotizing fasciitis

Question 29

Which SPE disease is associated with strep throat?

Answer 29

Scarlet fever

Question 30

Blood agar

Answer 30

Used to culture bacteria RBCs are placed in the agar, hardens into a plate Typically use sheep RBCs Clearing on the plate = hemolysis

Question 31

Difficulty with rheumatic fever

Answer 31

Auto-Abs to Strep. pyogenes Organisms are gone, can't treat with antibiotics Once affected by this, susceptibility lasts for a lifetime; next time you get infection, the auto-Abs are produced

Question 32

Strep. pyogenes affect on the kidneys

Answer 32

Acute glomerulonephritis Ag-Ab complexes lodged in glomeruli Results in edema, HTN, hematuria, proteinuria, decreased serum complement levels

Question 33

Diptheria

Answer 33

Deadly, toxin mediated disease Mild sore throat, slight fever, high fatigue, malaise Dramatic neck swelling Whitish gray membrane

Question 34

Diphtheria organism

Answer 34

Corynebacterium diphtheriae

Question 35

Corynebacterium diphtheriae features

Answer 35

Gram positive, variable shape | Sessile, non-spore forming

Question 36

Diphtheria exotoxin

Answer 36

Lysogenized by bacteriophage

Question 37

Pathogenesis of diphtheria

Answer 37

Not invasive, toxins are absorbed into bloodstream | Gray-white membrane: clotted blood, epithelial cells, leukocyte infiltrate

Question 38

How is the diphtheria toxin released?

Answer 38

Inactive form | A and B subunit

Question 39

Diphtheria subunits

Answer 39

A - inactivates EF-2 to stop protein synthesis | B - binding to host

Question 40

Where are the B subunit receptors in the body?

Answer 40

Heart Kidneys Nerve cells