Diagnosis of Pneumocystis carinii in sputum liquefied with the mucolytic agent dithiothreitol (sputasol).

Abstract

1. Light microscopic investigations : Sputasol treatment did not affect the staining properties of either the cyst wall or the parentheses-like structures by Gomori's methenamine silver nitrate (GMS) stain. Detection of Pneumocystis carinii was easier in the Sputasol-treated preparations because it was possible to prepare thin smears of the sediment, and because the cysts were concentrated. The amount of time needed for microscopic examination was reduced to the decreased amount of sediment in the Sputasol-treated samples. 2. Transmission electron microscope investigations : In the ultrastructure of P. carinii cysts stained with GMS stain, the heavier deposition of silver particles on the internally thickened parts of the cyst wall corresponded exactly with the distinctive appearance of the parentheses-like structures seen in light microscopic observations.