Gomez - Pulmonary Infections

Question 1

What two acute phase reactants indicate bacterial PNA over viral?

Answer 1

CRP

procalcitonin

Question 2

What are pts who have had splenectomies at risk for?

Answer 2

Increased risk of infection from encapsulated organisms

Question 3

What is the most common organism that causes pneumonia?

Answer 3

Strep pneumoniae

Question 4

What is the most common organism causing pneumonia in IV drug abusers?

Answer 4

Staph aureus

Question 5

What is the most common infectious agent found in pts with COPD?

What is the second most common?

Answer 5

1st: Haemophilus influenzae (Gram -)
2nd: Moraxella catarrhalis (Gram -)

Question 6

What type of organism must be covered for when treating suspected cases of Legionella?

Answer 6

Gram negative bacteria

Question 7

In what pt populations will you typically see pneumonia from Pseudomonas aeruginosa?

Answer 7

Pts w/ cystic fibrosis

Pts w/ neutropenia (i.e. on chemotherapy)

Question 8

What organism would you suspect if pt had pneumonia with presence of cold agglutinins?

Answer 8

Mycoplasma pneumoniae

Question 9

What is important to remember about organisms causing pneumonia in immunocompromised individuals?

Answer 9

They can get pneumonia from ALL OF THE COMMON organisms IN ADDITION TO the more rare organisms.

Question 10

Describe Strep pneumoniae

Answer 10

1 cause of bacterial pneumonia in adults

Gram(+) encapsulated diplococcus

α-hemolytic

Optochin sensitive

Question 11

Describe Haemophilus influenzae

Answer 11

Gram(-) coccobacilli

Capsule is major viral factor

H.iB is most common cause of bacterial meningitis in children 6mos-2yrs

Question 12

Describe Moraxella catarrhalis

Answer 12

Gram(-) diplococcus

Typically manifests as common cold, otitis media, sinusitis

Less commonly: bronchitis, laryngitis, pneumonia in children

Question 13

Describe Staphylococcus aureus

Answer 13

Gram(+) cocci in clusters

Catalase(+)

Coagulase(+)

In addition to skin infections, can cause pneumonia, meningitis, endocarditis, toxic shock syndrome

Some strains resistant to PCN and vanco

Question 14

Describe Legionella pneumophilia

Answer 14

Gram(-) bacilli

Grow in standing water

Causes lobar pneumonia with non-productive cough, fever, can lead to multi-organ failure and death

Question 15

Describe Klebsiella pneumoniae

Answer 15

Gram(-) encapsulated bacilli

Ferment lactose (red on MacConkey agar)

Most common cause of nosocomial respiratory tract infections

Causes hemorrhagic pneumonia w/ red jelly-colored sputum

Question 16

Describe Pseudomonas

Answer 16

Gram(-) rods

Oxidase(+)

Nonfermenter

Secretes antiphagocytic slime

Commonly present in lungs of pts w/ CF

Question 17

Describe Mycoplasma pneumoniae

Answer 17

Lack a cell wall

Causes atypical “walking” pneumonia

Associated with cold agglutinin (anti-I) production

Question 18

Describe Chlamydia ssp. with respect to respiratory disease

Answer 18

Gram(-) coccoid to rod

Produce infectious elementary bodies

Cannot produce ATP

• pneumoniae* strain causes atypical pneumonias (upper and lower)
• psittaci* strain causes bird fancier’s disease

Question 19

Describe Coxiella burnetti

Answer 19

Gram(-) intracellular parasite

Found in farm animals and their products (ex. milk)

Has an endospore-like state resistant to environmental insult

Causes Q fever

Question 20

Describe Bacillus anthracis

Answer 20

Gram(+) bacilli in chains

Question 21

Describe Yersinia pestis

Answer 21

Gram(-) coccobacilli

Non-lactose fermenter, but does ferment glucose

Question 22

Describe pneumonic plague

Answer 22

Occurs in crowded conditions

Spread by respiratory droplets

Shorter incubation period and greater mortality than bubonic

Question 23

Describe Mycobacteria

Answer 23

Gram ambiguous (cell wall is (+), but (-) by DNA)

Acid fast - use Ziehl-Neelsen stain to ID

Question 24

What is a Ghon complex?

Answer 24

Found in tuberculosis infection

Calcified parenchymal necrotic lesion and associated lymph node