Which of the following statements best describes the laboratory diagnosis of Pneumocystis carinii?
|A||India ink stain of bronchoalveolar lavage material|
|B||KOH stain of lung biopsy tissue|
|C||Growth of the organism on Sabouraud agar|
|D||Methenamine silver stain of induced sputum|
a. Until, recently, Pneumocystis,an important opportunistic infection in AIDS patients, was classified as aprotozoan, but it is now regarded as an atypical fungus.
b. It attaches to lung cells (pneumocytes) and can give rise to a fatal pneumonia-like disease
c. Because Pneumocystis species are not able to be grown in the laboratory, staining procedures constitute the primary diagnostics techniques used.
d. This infection does not respond to traditional antifungal chemotherapy.
e. Being found primarily in the lungs in many normal individuals, disease occur in immunocompromised individuals, malnourished, severe COPD, and dissemination is rare.
Specimens of bronchoalveolar lavage, lung biopsy, or induced sputum are stained (Giemsa or methenamine silver, e.g.) and examined for cysts or trophozoites.
More sensitive than staining is antigen detection by direct fluorescent antibody test.