A 50-year-old man, a recent immigrant from Vietnam, is brought to the emergency room with a cough productive of bloody sputum. He first noticed a cough approximately 2 months ago, but there was not much sputum. In the past several days his sputum production has increased and become mixed with blood. He reports having lost approximately 15 lb in this time frame as well. He also notes that he’s had …drenching night sweats 2 or 3 nights a week for the past month. He has a 50-pack-year smoking history but no other medical history. He came to the United States from Vietnam 7 months ago. On examination, he is a thin, frail-appearing male. His vital signs are normal. His head and neck exam is normal. He has no palpable adenopathy in his neck or axilla. His lung exam is notable only for decreased breath sounds diffusely. A chest x-ray shows a cavitary infiltrate of the left upper lobe.

1: what type of organism is likely to be seen on a gram stain of a sputum sample?
A: gram positive
B: colorless “ghost” cells
C: gram negative
D: gram variable
E: more than one of these results

2: what staining technique is most commonly used to identify this organism?
A: gram stain
B: endospore stain
C: capsule stain
D: acid fast stain
E: flagellar stain

3: the most common method of transmission of this particular pathogen is via:
A: direct contact
B: fomite
C: droplet
D: vector
E: vehicle transmission
4: which organism is most likely to cause frankly bloody sputum?
A: streptococcus pneumonia
B: mycobacterium tuberculosis
C: klebsiella pneumonia
D: influenza virus
E: none of these

5: how is the organism responsible for the patient disease grown?
A: the footpad of the armadillo
B: anaerobically on nutrient broth agar
C: in 5% carbon dioxide at room temperature
D: in 5% carbon dioxide at 37 degrees on Lowenstein- Jensen medium
E: in culture of human macrophages

6: when would you start antimicrobial therapy for this patient?
A: after a culture has confirmed that he has TB
B: after a repeat PPD test that is positive
C: after acid fast bacteria were seen in his sputum
D: after the results of this HIV TEST, because this will affect the type of therapy he gets
E: no therapy is necessary as the immune response will certainly overcome the infection

7: what would the recommended therapy be?
A: penicillin and streptomycin
B: isoniazid alone
C: isoniazid plus ethambutol
D: isoniazid plus rifampin
E: isoniazid plus rifampin plus pyrazinamide

8: what is the pathogenesis of the lesion seen on the x-ray?
A: a granuloma with central (caseous) necrosis
B: an inflammatory response with edema fluid
C: nitrous oxide killing of the bacteria
D: one love completely filled with fluid
E: a tumor

9: what result would you expect based on the finding of acid fast bacteria from the PPD test and when?
A: redness and swelling (10mm) at the site of injection after 12 hours.
B: redness and swelling (10mm) at the site of injection after 24 hours.
C: redness and swelling (10mm) at the site of injection after 3 days.
D: redness and swelling (10mm) at the site of injection after 1 hour.
E: no reaction at the site of injection.