[Pneumocystis carinii--diagnosis based on DNA amplification technique]
Jolanta Powierska-Czarny1, Eugenia Gospodarek, Mieczysława Czerwionka-Szaflarska
1Zakład Mikrobiologii AM w Bydgoszczy. jolantapowierska@o2.pl
Abstract:
Pneumocystis carinii f. sp. hominis is an important cause morbidity and morality, causing P. carinii pneumonia (PCP) in AIDS and other immunocompromised patients. Long thought of as protozoan, molecular analysis of the ribosomal gene locus first demonstrated that P. carinii is a member of the fungal kingdom. Currently P. carinii is considered to be fungus likely to Ascomycetes, based on its ultrastructure, certain elements of its cellular biology, and nucleotide sequences of main genetic loci. The standard method for diagnosis P. carinii is microscopic examination of stained (immunofluorescent or conventional tinctorial) invasive specimens: BAL (bronchoalveolar lavage), lung biopsy or induced sputum with sensitivity varying range from <50% to >90%. Molecular detection system have the potential to provide a higher degree of sensitivity than microscopic method. PCR technique have been applied to lower respiratory tract clinical specimens and recently to non-invasive oral washes as well. Because P. carinii infection can be rapidly progressive and success of therapy dependent to the time of the initial therapy, early diagnosis and treatment is essential.
Insights
Pneumocystis carinii pneumonia (PCP) is a serious fungal infection in immunocompromised individuals. Molecular methods show promise for earlier and more sensitive diagnosis than traditional microscopy.
Area of Science:
- Mycology
- Infectious Diseases
- Molecular Biology
Background:
- Pneumocystis carinii f. sp. hominis causes Pneumocystis pneumonia (PCP) in immunocompromised patients.
- Initially classified as a protozoan, molecular data reclassified P. carinii as a fungus, likely an Ascomycete.
- PCP is a significant cause of morbidity and mortality in patients with AIDS and other immune deficiencies.
Purpose of the Study:
- To review the diagnostic methods for P. carinii pneumonia.
- To highlight the potential of molecular detection systems for improved sensitivity.
- To emphasize the importance of early diagnosis and treatment for P. carinii infection.
Main Methods:
- Microscopic examination of stained invasive specimens (BAL, lung biopsy, induced sputum).
- Molecular detection techniques, including Polymerase Chain Reaction (PCR).
- Application of PCR to lower respiratory tract specimens and non-invasive oral washes.
Main Results:
- Microscopic diagnosis sensitivity varies widely (<50% to >90%).
- Molecular detection systems offer potential for higher sensitivity than microscopy.
- PCR has been successfully applied to various clinical specimens, including oral washes.
Conclusions:
- Pneumocystis carinii is a fungus, not a protozoan.
- Early diagnosis of P. carinii pneumonia is crucial for effective treatment.
- Molecular diagnostic tools, like PCR, may improve early detection rates.
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