Pneumocystis carinii Identified by Gram Stain of Lung Imprints

Excerpt

Because Pneumocystis carinii cannot be readily cultivated and because reliable serologic techniques are unavailable, the diagnosis of P. carinii pneumonia continues to depend on detecting the organisms in pulmonary secretions or lung tissue (1). Almost always, an invasive diagnostic procedure is necessary, and diagnostic samples are obtained by bronchoscopy, transbronchial biopsy, transthoracic aspiration, or open lung biopsy, the precise procedure being determined by the patient's clinical status and the expertise available at the institution. It is generally believed that P. carinii can only be recognized if special stains such as methenamine silver (2), toluidine blue (3), or Gram Weigert (4)