RTI VI

Question 1

summarize community-acquired pneumonia and hospital-acquired pneumonia

Answer 1

Question 2

list common typical causes of CAP

Answer 2

• Streptococcus pneumoniae
• H. influenzae
• Klebsiella
• Staph aureus

Question 3

name clinical features associated with typical CAP

Answer 3

• usually one lobe involved
• acute onset, increased fever, pleuritic chest pain, productive cough
• signs of consolidation:
  
  • dullness
  • vocal fremitus/resonance
  • egophony
  • whispered pectoriloquy
  • bronchial breath sounds
• Dx = CXR

Question 4

describe the appearance of S. pneumoniae on blood agar

Answer 4

Question 5

describe the appearance of S. pyogenes on blood agar

Answer 5

Question 6

_____ is the commonest cause of community-acquired pneumonia

Answer 6

S. pneumoniae is the commonest cause of community-acquired pneumonia

Question 7

describe the pathogenesis of Pneumococcal pneumonia

Answer 7

• capsule
• IgA protease
• pneumolysin
• autolysin
• transformation

Question 8

describe properties of pneumolysin

Answer 8

Question 9

describe the sputum seen in S. pneumoniae infection

Answer 9

rusty colored (reddish-brown)

Question 10

describe prevention of Pneumococcal pneumonia and the high risk populations it is indicated for

Answer 10

• “polyvalent” capsular polysaccharide vaccine
• immunizes against 23 of the most common serotypes
• high risk individuals:
  
  • age >65
  • chronic disease
  • HIV
  • alcoholism
  • splenectomy patients

Question 11

Klebsiella is a (G+ve/G-ve) ____ (shape)

Answer 11

Klebsiella is a G-ve bacillus

Question 12

Klebsiella has a large ____, which gives it a mucoid appearance

Answer 12

Klebsiella has a large polysaccharide capsule, which gives it a mucoid appearance

Question 13

Klebsiella causes ____ of lung tissue, due in part to response to _____

Answer 13

Klebsiella causes necrotization of lung tissue, due in part to response to endotoxin (LPS)

Question 14

name the at-risk individuals for Klebsiella infection

Answer 14

• CAP
  
  • alcoholics
  • diabetics
  • COPD
• HAP
  
  • ventilators
  • IV catheters

Question 15

describe the sputum seen in Klebsiella infection

Answer 15

“red currant jelly” sputum

Question 16

in Klebsiella pneumoniae, 2 high affinity ___ uptake systems: _____& _____ helps in bacterial growth

Answer 16

in Klebsiella pneumoniae , 2 high-affinity iron uptake systems: aerobactin & enterochelin helps in bacterial growth

Question 17

describe the role of the LPS in Klebsiella pneumoniae

Answer 17

• LPS (O antigen)
  
  • prevents ingestion by phagocytes, detection of somatic antigens by host’s antibodies
  • impedes complement (especially C3b); inhibits opsonization

Question 18

Klebsiella pneumoniae produces ____ which gives it ____ resistance

Answer 18

Klebsiella pneumoniae produces carbapenemase which gives it carbapenem resistance

Question 19

the ___ found in Klebsiella pneumoniae allows attachement to ____ and ____ formation

Answer 19

the pili (fimbriae) found in Klebsiella pneumoniae allows attachment to epithelium and biofilm formation

Question 20

describe the spread of Klebsiella pneumoniae

Answer 20

exposure to bacteria required, person to person via contamination of hands or environment (NOT spread through air)

Question 21

describe the Sketchy

Answer 21

Question 22

Pseudomonas sp. is found in _____

Answer 22

Pseudomonas sp. is found in still fresh water sources

Question 23

list the persons that are at highest risk for Pseduomnas infections

Answer 23

• particularly dangerous for persons with structural defects in body defenses:
  
  • burn victims
  • CF
  • HAP

Question 24

the most common infection caused by Pseudomonas sp. is _____

Answer 24

the most common infection caused by Pseudomonas sp. is otitis externa aka swimmer’s ear

Question 25

*Pseduomonas* are (G+ve/G-ve) ____ (shape)

Answer 25

*Pseduomonas* are **G-ve** **rods**

Question 26

describe the sputum color in *Pseudomonas* infections

Answer 26

**blue-green/yellow-green sputum**

Question 27

\_\_\_\_\_ and ____ are considered as *bona fide* CF pathogens

Answer 27

**Pseudomonas aeruginosa** and **Burkholderia cepacia** are considered as bona fide CF pathogens

Question 28

describe the Sketchy

Answer 28

Question 29

list the most common atypical causes of CAP

Answer 29

* most common "atypical" causes: * Mycoplasma pneumoniae * Chlamydophila pneumoniae * Legionella pneumophila

Question 30

\_\_\_\_ is the most common cause of atypical CAP

Answer 30

**Mycoplasma pneumoniae** is the most common cause of atypical CAP

Question 31

describe features related to Mycoplasma pneumoniae lack of cell wall

Answer 31

* due to lack of cell wall: * unreactive to Gram stain * extremely susceptible to desiccation and intrinsically resistant to B-lactam antibiotics

Question 32

describe where outbreaks of Mycoplasma pneumoniae commonly occur

Answer 32

* outbreaks lasting months occur in crowded institutional settings (military, colleges, prison, etc.)

Question 33

describe adhesion molecules found in Mycoplasma pneumoniae

Answer 33

* specialized attachment organelle (P1 adhesin and accessory proteins)

Question 34

Mycoplasma pneumoniae production of ____ mediates tissue destruction

Answer 34

Mycoplasma pneumoniae production of **H2O2** mediates tissue destruction

Question 35

Mycoplasma pneumoniae ____ leads to cytotoxic effect on the resp. epithelium during acute infection

Answer 35

Mycoplasma pneumoniae **community acquired resp. distress syndrome (CARDS)** leads to cytotoxic effect on the resp. epithelium during acute infection

Question 36

Mycoplasma pneumoniae attaches to and damages ____ at the base of ___ which causes prolonged paroxysmal cough and activates the immune system

Answer 36

Mycoplasma pneumoniae attaches to and damages **the respiratory epithelial cells** at the base of **cilia** which causes prolonged paroxysmal cough and activates the immune system

Question 37

describe the diagnosis of Mycoplasma pneumoniae

Answer 37

* serology: * serum cold agglutination * non-specific * negative result does not exclude infxn * \> 4-fold increase or decrease supports the diagnosis

Question 38

describe the Sketchy

Answer 38