L19

Question 1

True or False: Non-bacterial agents (viral) are responsible for majority of URI

Answer 1

True

Question 2

Bronchitis, Bronchiolitis, and Pneumonia are infections of the ___
A. URT
B. LRT

Answer 2

B. LRT

Question 3

True or False: Oral and nasal cavities have natural flora, but the URT is sterile

Answer 3

False - while oral/nasal cavities have NF, the LRT is sterile

Question 4

Which two pathogens can cause URT infection in the throat – specifically 1) Strep throat and 2) Diptheria?

Answer 4

1) Strep throat - S. pyogenes

2) Diptheria - Corynebacterium diptheria

Question 5

True or False: Pneumonia, Whooping Cough, and Tb or LRT infections

Answer 5

True

Question 6

True or False: Mycobacterium tuberculosis causes: TB or Chronic pneumonia

Answer 6

True

Question 7

Mycoplasma,
Ureaplasma, and Chlamydia, Legionella are all atypical pneumonias, which can cause __ infection
A. URT
B. LRT

Answer 7

B. LRT

Question 8

Bordetella pertussis can cause which LRT infection?
A. Pneumonia
B. Whooping Cough
C. Strep

Answer 8

B. Whooping Cough

Question 9

What is the #1 bacterial agent of pharyngitis?
A. Mycoplasma
B. Streptococcus pyogenes
C. Cutibacterium acnes
D. Strep aureus

Answer 9

B. Streptococcus pyogenes
- Group A Strep
- Gram-positive cocci, chains

Question 10

Which three adhesions (microbial surface components recognizing adhesive matrix molecules) are used by S. pyogenes for virulence?

Answer 10

1. M protein
2. Fibronectin and Collagen binding protein

Question 11

Which three strategies are used by S. pyogenes to evade host immune
response?

Answer 11

1. Capsule (contains HA)
2. M Protein (antigenic variation)
3. C5a Peptidase

Question 12

True or False: S. pyogenes uses toxins (SPE) and enzymes (e.g - Streptolysin S and O; Streptokinase)

Answer 12

True

Question 13

What is the function of Streptolysin S and O + Streptokinase in S. pyogenes?

Answer 13

Streptolysin S and O = Lyse RBC

Streptokinase = Activates plasminogen to plasmin to dissolve clots

Question 14

True or False: In addition to causing strep, S. pyogenes can cause Scarlet Fever + Necrotizing Fascitis

Answer 14

True

Question 15

What happens if you don’t treat pharyngitis (aka - secondary sequlae)?

Answer 15

1. Scarlet Fever - SPE
2. Rheumatic Fever
3. AGN

Question 16

If pharyngitis goes untreated, Rheumatic fever could develop, leading to “molecular mimicry” in which Abs for GAS cross-react
with the host ___ tissue

Answer 16

Cardiac

Question 17

Deposition of antigen-Abs for GAS in the
glomerular basement membrane activate
complement and induces inflammation. This can result when ___ is not treated

Answer 17

Pharyngitis

Question 18

Complications of S. pyogenes infection?

Answer 18

Question 19

S. pyogenes lab diagnosis?

Answer 19

Question 20

Chart

Answer 20

Question 21

True or False: Immunization is important for avoiding Corynebacterium infection

Answer 21

True

Question 22

True or False: Corynebacterium diptheria occurs in palisades and is a gram (+) pleomorphic rod

Answer 22

True

Question 23

C. diptheria uses an AB toxin. B binds to ___ while A is ___ portion/inactivates ___

Answer 23

receptor/heparin-binding epidermal GF (heart and nerves); enzymatic; EF-2

Question 24

True or False: C. diptheria uses toxin carried on a bacteriophage; regulated by iron

Answer 24

True

Question 25

Under what conditions will C. diptheria not transcribe toxin genes?

Answer 25

When there's enough Fe - Both Fe/DtxR will bind to toxin operator

Question 26

True or False: Under low Fe conditions, there is release of DtxR (diptheria toxin repressor) -- which allows for transcription of toxin gene

Answer 26

True

Question 27

Why is C. diptheriae infection associated with painful swallowing?

Answer 27

- Leads to pseudomembrane formation (bacteria, plasma cell, dead cells)

Question 28

Which test can be used to dx C. diptheria?

Answer 28

Elek Test

Question 29

True or False: In bronchiolitis, airway becomes obstructed from swelling of bronchiole walls

Answer 29

True

Question 30

Which gram (-) cococobacilli is the causative agent of Pertussis/Whooping cough? Where does it adhere?

Answer 30

Bordetella pertussis - Adheres to: ciliated epithelial cells in trachea

Question 31

True or False: Pertussis/Whopping Cough mostly affects trachea and bronchi

Answer 31

True

Question 32

What MOA is used by B. pertussis to cause airway swelling?

Answer 32

Makes A-B5 type toxin that binds to G-alpha inhibitory subunit Increases cAMP and mucous production, as well as death/sloughing of infected cells

Question 33

What is the most contagious stage of Pertussis? A. Common Cold B. Paroxysmal cough C. Convalescent stage

Answer 33

A. Common Cold

Question 34

Stages of Pertussis?

Answer 34

Common Cold, Paroxysmal Cough, and Convalescent Stage

Question 35

How do organisms enter lung to cause pneumonia?

Answer 35

1) Aspiration - S/K pneumo 2) Inhalation of aerosols 3) Hematogenous - S. aureus

Question 36

Pneumonia is associated with necrotic/apoptotic type _ cells

Answer 36

1

Question 37

Which two extracellular bacteria cause Typical pneumonia (lobar)?

Answer 37

K/S Pneumoniae

Question 38

Which two agents cause Host-compromised Pneumonia (cancer)?

Answer 38

Nocardia + P. aero

Question 39

Atypical (interstitial) pneumonia can be caused by which three agents?

Answer 39

1. Legionella 2. Mycoplasma 3. Chylamydia

Question 40

Chronic pneumonia is caused by which 2 anaerobes?

Answer 40

1) Fungi 2) M. tuberculosis

Question 41

Consolidation/Lobar Pneumonia is associated with which Gram positive bacteria?

Answer 41

S. pneumo

Question 42

Which gram (+) bacteria is the major cause of community-acquired pneumonia? Why are epidemics unlikely in this case?

Answer 42

S. pneumo - Due to aspiration (not contagious!)

Question 43

S. pneumo features?

Answer 43

Gram (+) Lancet shape Encapsulated diplococci Catalse/coag (-)

Question 44

What is major virulence factor used by S. pneumo?

Answer 44

Capsule polysaccharide - basis of vaccine

Question 45

Rusty colored sputum suggets ___ pneumonia

Answer 45

Lobar/Consolidation

Question 46

S. pneumo dx?

Answer 46

Question 47

True or False: Atypical Pneumonias are fastidious, grow slow, and lack peptidoglycan layer

Answer 47

True - also, most cause destruction of ciliated respiratory epithelium

Question 48

True or False: M. pneumo and U. urealyticum are extracellular pathogens while Chlamydia are obligate intracellular

Answer 48

True

Question 49

True or False: Only M. pneumo and C. pneumo are transmitted person to person -- U. urealyticum and C. trachomatasis are transmitted vertically

Answer 49

True

Question 50

True or False: M. tuberculosis is associated with chronic pneumonia

Answer 50

True - Note: AFB (+)

Question 51

True or False: M. tuberculosis do NOT have gram stain and do NOT grow on blood agar -- there cell contains mycolic acid

Answer 51

True

Question 52

True or False: Mycobacteria are often referred to as acid-fast bacilli (AFB)

Answer 52

True - rod shaped - resistant to decolorization by acid

Question 53

What primary stain can bind to mycolic acid in mycobacteria?

Answer 53

Carbolfuschin - decolor = acid OH - counter = meth blue

Question 54

Which two virulence factors are used by mycobacteria (M Tb)?

Answer 54

1. mycolic acid 2. cord factor - glycolipid found in cell wall

Question 55

True or False: M Tb is INTRACELLULAR BACTERIA + primary defense is cell mediated ( T cell )

Answer 55

True

Question 56

True or False: M Tb induces hypersensitivity + it can replicate/survive in macrophages (facultative intracellular)

Answer 56

True

Question 57

Blood sputum suggests __

Answer 57

Tb

Question 58

Tb dx?

Answer 58