Pneumonia

Question 1

How does pneumonia enter the respiratory tract?

Answer 1

Droplets – inhaled into lungs.

Aspiration - unable to protect airways from secretions by glottic closure and coughing.

Bacteremia

Question 2

Lung antimicrobial peptides

Answer 2

Lysozyme, lactoferrin, defensins, collectins

Question 3

Lung cells that interact with inhaled microbes

Answer 3

Alveolar macrophages
Dendritic cells
PMNs
NK cells

Question 4

Virulence factors of microorganisms that cause pneumonia have this in common

Answer 4

They inhibit host defenses in lung like mucus cilia elevator and activity of IgA.

Question 5

Chlamydophila pneumonia virulence factor

Answer 5

Ciliostatic factor

Question 6

Mycoplasma pneumoniae virulence factor

Answer 6

Can cut cilia

Question 7

Influenza lung virulence factor

Answer 7

Reduces tracheal mucus velocity

Question 8

Strep pneumo virulence factor?

Answer 8

Produces a protease that can split sIgA and has capsule to evade exocytosis

Question 9

What are factors that increase the inoculum of ingested bacteria?

Answer 9

Gastric dysfunction, gingival or sinus disease, achlorhydria, prolonged critical illness, endotrachial intubation/tracheotomy.

Question 10

Strep Pneumonia appearance

Answer 10

Gram positive diplococci/chains

Question 11

Strep pneumonia causes pneumonia what % of the time?

Answer 11

50% of pneumonias that require hospitalizations

Question 12

Where does strep pneumonia live?

Answer 12

Oropharynx in normal adults.

Question 13

Staph aureus appearance

Answer 13

Gram positive cocci in clusters

Question 14

Major settings of staph aureus pneumonia

Answer 14

Secondary complication of respiratory tract infection with influenza.

Hospitalized patient with impaired host defenses

Widespread dissemination through bloodstream.

Question 15

Hemophilus influenzae appearance

Answer 15

Small gram negative coccobacilli

Often conolize the nasopharynx of normal individuals and lower airways of patients with COPD

Question 16

Klebsiella pneumonia

Answer 16

Large gram negative bacillus normally found in GI tract. Often seen in the setting of underlying alcoholism

Can cause thick bloody mucoid sputum “currant jelly sputum”

Question 17

Pseudomonas Aeruginosa

Answer 17

Gram negative bacillus, wide variety of environmental sources
Primarily seen in patients who are debilitated, hospitalized, and often previously treated with antibiotics.

Question 18

legionella pneumophila

Answer 18

Gram negative bacillus, stains poorly and isn’t seen by usual staining methods. Can affect previously healthy individuals.

Question 19

Chlamydophila Pneumoniae

Answer 19

Obligate intracellular, not readily cultured. Causes 5-10% of pneumonia.

Question 20

Mycoplasma pneumoniae

Answer 20

Smallest freeliving organisms

Intermediate between viruses and bacteria (don’t have rigid cell walls, but dont require host machinery to replicate)

Common cause of walking pneumonia. Common in young adults.

Question 21

Pathology of pneumonia

Answer 21

Infection and inflammation of the distal pulmonary parenchyma. Influx of neutrophils, edema, erythrocytes, mononuclear cells, fibrin.