8. Atypical Pneumonias

Question 1

Genus of cell wall deficient bacteria

Answer 1

Mycoplasma

Question 2

Aspergillus wet prep stain

Answer 2

Lactophenol Cotton Blue stain

Question 3

Old and current method of M. pneumoniae lab detection

Answer 3

Past: complement fixation (CF)

Current: ELISA

Question 4

Difference between ZN and Kinyoun stain?

Answer 4

ZN = requires heat

Kinyoun = cold method of ZN w/ higher phenol and basic fuchsin concentration

Question 5

Requires cell lines to culture

Answer 5

Chlamydophila pneumoniae

Question 6

Most common method of diagnosing M. pneumoniae

Answer 6

ELISA

Question 7

Primary stain, decolourizer, and counterstain for Kinyoun acid fast?

Answer 7

Primary = carbol fuchsin

Decolourizer = 3% acid-alcohol

Counter = methylene blue or brilliant green

Question 8

3 second line M. tuberculosis drugs

Answer 8

Kanamycin
Amikacin
Capreomycin (injectable)

Question 9

Which organism? Buffered charcoal yeast extract agar

Answer 9

Legionella pneumoniae

Question 10

Counterstain for acid-fast stains

Answer 10

Methylene blue or Brilliant Green

Question 11

No culture options currently exist for this organism

Answer 11

Pneumocystis jiroveci

Question 12

Mycoplasma pneumoniae atmospheric requirements

Answer 12

Increased moisture but NOT increased CO2

Question 13

This organism can target any organ system; most serious infections seen in the elderly, smokers, alcoholics

Answer 13

Legionella pneumophila

Question 14

3 types of specimens that may be sent for Aspergillus culture

Answer 14

• Sputum
• BAL
• Lung biopsy

Question 15

How does the lab detect M. tuberculosis

Answer 15

Acid-Fast stain

Question 16

2 culture media for M. tuberculosis

Answer 16

Lowenstein-Jensen

Middlebrook

Question 17

Organism found in hospital showerheads

Answer 17

Aspergillus spp.

Question 18

How are potential Legionella specimens treated prior to media inoculation to reduce normal URT colonizers

Answer 18

Heat or acid treatment

Question 19

Which organism? SP4 broth and agar

Answer 19

Mycoplasma pneumoniae

Question 20

Often implicated in “walking pneumonia”

Answer 20

Mycoplasma pneumoniae

Question 21

Organism w/ intrinsic resistance to penicillins, cephalosporins, aminoglycosides

Answer 21

Legionella pneumophila

Question 22

Thin, faint gnb that may be missed in direct smears

Answer 22

Legionella

Question 23

Fluorescent acid-fast stain that attaches to the mycolic acid on cell walls

Answer 23

Traunt

Question 24

Which organism? Cell culture w/ HeLA229 cells

Answer 24

Clamydophila pneumoniae

Question 25

5 first line M. tuberculosis drugs

Answer 25

Isoniazid = INH
Rifampin
Pyrazinamide = PZA
Ethambutol - loss of colour vision
Streptomycin - ototoxic

Question 26

Treatment may be switched to this antibiotic once C. pneumoniae is confirmed to be the causative agent

Answer 26

Doxycycline

Question 27

What colour do AFB organisms appear as?

Answer 27

Dark pink/red

Question 28

Organism w/ microscopic fried egg colony appearance

Answer 28

Mycoplasma pneumoniae

Question 29

Organism that may be detected by fungi-fluor (Cellufluor) or Calcofluor White WITHOUT KOH

Answer 29

Pneumocystis jiroveci

Question 30

Unlike other pneumonias, infection by this organism rarely develops serious complications

Answer 30

Mycoplasma pneumoniae

Question 31

How are M. tuberculosis sputums processed?

also applies to urines, skin specimens

Answer 31

Liquefactionated and decontaminated (to kill most bacteria that aren’t M. tuberculosis)

Question 32

Not often implicated in human disease; species are usually inhibited at 37C

Answer 32

Penicillium

Question 33

Which organism? Lowenstein-Jensen media

Answer 33

Mycobacterium tuberculosis

Question 34

Most often used as a first line antifungal

Answer 34

Voriconazole

Question 35

Typical abx treatment for Legionella

Answer 35

Macrolides (erythromycin, clarithromycin, azithromycin)

Question 36

Abx to treat Legionella?

Answer 36

Macrolides or fluoroquinolones

Question 37

Will NOT grow on BAP/CHOC but will grow on BCYE

Answer 37

Legionella pneumophila

Question 38

Used extensively as a last resort drug in “extensively drug resistant TB” (XDRTB)

Answer 38

Cycloserin

Question 39

Once a rare form of pneumonia in neonates but now it’s almost exclusively found in the immunocompromised

Answer 39

Pneumocystis pneumonia (PCP)

Question 40

Aspergillus specimens may be examined by this direct exam method

Answer 40

KOH prep w/ calcofluor white stain

Look for fungal elements

Question 41

How are M. pneumoniae specimens prepared for media inoculation?

Answer 41

Filtered to eliminate competing yeast and bacteria

Question 42

AKA Traunt acid-fast stain

Answer 42

Auramine-Rhodamine

Question 43

Difference between Legionnaire’s disease and Pontiac fever?

Answer 43

Legionnarie’s = a pneumonia

Pontiac fever = a systemic infection, non-pneumonic

Question 44

____________ are found in no more than 50% of M. pneumoniae infections

Answer 44

Cold agglutinins

Question 45

Atmosphere required for M. tuberculosis

Answer 45

10% CO2

Question 46

2 forms of legionellosis

Answer 46

• Legionnaire’s disease
• Pontiac fever

Are actually 2 forms of legionellosis

Question 47

Media for this organism must contain glucose and/or arginine, serum for cholesterol, and antibiotics to prevent overgrowth by other bacteria

Answer 47

Mycoplasma pneumoniae

Question 48

3 components of the Lactophenol Cotton Blue stain and their purposes

Answer 48

Phenol - kills live organisms

Lactic acid - preserves fungal structures

Cotton Blue Stain - stains chitin in fungal cell walls

Question 49

M. pneumoniae is the only mycoplasma that is positive for this specific identification test

Answer 49

Hemadsorption

Question 50

Associated with water and water systems, is chlorine resistant, survives a variety of temps

Answer 50

Legionella pneumophila

Question 51

Infective and replicative form of Chlamydophila

Answer 51

Infective = elementary body (EB)

Replicative = reticulate body (RB)