A. Microscopy

Question 1

• Acid-fast staining

—singly, in parallel bundles, or in globular masses.

Answer 1

Typical acid-fast bacilli

Question 2

Slit skin smear method.

• [1} the site tight.
• [2]
• [3} and collect material.
• [4}on slide.
• [5} and fix.

Answer 2

• Pinch
• Incise
• Scrape
• Smear
• Air-dry

Question 3

Nocardia in sputum.

A. Note the filamentous bacteria forming tree-like branches among the neutrophils the beaded appearance of the

Answer 3

rods

Question 4

Nocardia in sputum.

B. The same sputum stain with the modified (weaker) acid- fast method. Note the [?] with the same branching pattern as in A.

Answer 4

red filaments

Question 5

readily stain with aniline dyes and

by silver impregnation techniques

Answer 5

B. burgdorferi

Question 6

Microscopic visualization of [?] in tissues is too insensitive for most
stages of the disease because:
- Rare numbers of spirochetes are unevenly distributed in clinical
samples.
- Spirochete morphology is also variable and may be difficult to distinguish from host tissues in histologic sections.
- Highly nonspecific and may detect any type of bacterium.

Answer 6

B. burgdorferi