Skip directly to search Skip directly to A to Z list Skip directly to site content
CDC Home
For questions about DPDx, contact us

DPDx is an education resource designed for health professionals and laboratory scientists. For an overview including prevention and control visit


[Pneumocystis jirovecii]

Laboratory Diagnosis

The specific diagnosis is based on identification of P. jirovecii in bronchopulmonary secretions obtained as induced sputum or bronchoalveolar lavage (BAL) material. In situations where these two techniques cannot be used, transbronchial biopsy or open lung biopsy may prove necessary. Microscopic identification of P. jiroveci trophozoites and cysts is performed with stains that demonstrate either the nuclei of trophozoites and intracystic stages (such as Giemsa) or the cyst walls (such as the silver stains). In addition, immunofluorescence microscopy using monoclonal antibodies can identify the organisms with higher sensitivity than conventional microscopy.

Molecular Diagnosis

Molecular diagnosis of Pneumocystis jirovecii.

Agarose gel (2%) analysis of PCR-amplified products from DNA extracted from a broncho alveolar lavage (BAL) diagnostic specimen of a patient with pulmonary symptoms.

Molecular methods for detection of P. jirovecii have shown very high sensitivity and specificity and constitute the gold standard for detection of this pathogen.

Agarose gel (2%) analysis of PCR-amplified products from DNA extracted from a bronchoalveolar lavage (BAL) diagnostic specimen of a patient with pulmonary symptoms.

  • Lane S: Molecular base pair standard (100-bp ladder). Black arrows show the size of standard bands.
  • Lane 1: Single step PCR amplification with the pAZ102-E/pAZ102-H primer pair1 - diagnostic band size: 346 bp.
  • Lane 2: Nested PCR amplification with the ITS nested PCR primers, 1724F/ITS2R (first round) and ITS1F/ITS2R1 (second round)2 - diagnostic band size: 550 bp.
  1. Wakefield AE, Pixley FJ, Banerji S, Sinclair K, Miller RF, Moxon ER, Hopkin JM. Amplification of mitochondrial ribosomal RNA sequences from Pneumocystis carinii of rat and human origin. Mol Biochem Parasitol 1990;43:69-76.
  2. Lu JJ, Chen CH, Bartlett MS, Smith JW, Lee CH. Comparison of six different PCR methods for detection of Pneumocystis carinii. J Clin Microbiol 1995;33:2785-2788.

Back to Top

For questions about DPDx, contact us
  • Page last reviewed November 29, 2013
  • Page last updated November 29, 2013
  • Content source: Global Health - Division of Parasitic Diseases and Malaria
  • Notice: Linking to a non-federal site does not constitute an endorsement by HHS, CDC or any of its employees of the sponsors or the information and products presented on the site. The U.S. Government's Official Web PortalDepartment of Health and Human Services
Centers for Disease Control and Prevention   1600 Clifton Road Atlanta, GA 30329-4027, USA
800-CDC-INFO (800-232-4636) TTY: (888) 232-6348 - Contact CDC–INFO