Giemsa staining for cysts and trophozoites of Pneumocystis carinii
1Department of Infectious Diseases and Microbiology, Westmead Hospital, Australia.
Abstract:
Although Giemsa staining has been routinely used for the detection of trophozoites and intracystic bodies in smears of bronchoalveolar lavage fluid (BAL) from patients with Pneumocystis carinii pneumonia, it does not normally stain the cyst wall. For detection of the cysts other stains such as toluidine Blue 'O' and methenamine silver must be used as well. Sulphation of smears before staining with Giemsa allows cysts to be visualised, thus enabling a single stain to be used to show all the stages of BAL or sputum, which is particularly useful, considering the increase in the prevalence of P carinii pneumonia in conjunction with the spread of AIDS.
Insights
Giemsa staining can now visualize Pneumocystis pneumonia cysts in bronchoalveolar lavage fluid. Sulphation before Giemsa staining enables a single-stain method for all Pneumocystis parasite stages.
Area of Science:
- Medical diagnostics
- Microbiology
- Pathology
Background:
- Giemsa staining is standard for Pneumocystis carinii pneumonia (PCP) detection in bronchoalveolar lavage (BAL) fluid.
- Giemsa staining typically does not visualize the Pneumocystis cyst wall.
- Detecting Pneumocystis cysts often requires additional stains like toluidine Blue 'O' or methenamine silver.
Purpose of the Study:
- To improve Pneumocystis carinii pneumonia diagnosis by modifying Giemsa staining.
- To enable visualization of Pneumocystis cysts using a single staining technique.
Main Methods:
- Smears of bronchoalveolar lavage fluid were treated with sulphation prior to Giemsa staining.
- Evaluated the effectiveness of the modified Giemsa stain for visualizing all Pneumocystis parasite stages, including cysts.
Main Results:
- Sulphation of smears before Giemsa staining allowed for the visualization of Pneumocystis cysts.
- The modified Giemsa stain successfully demonstrated all stages of Pneumocystis in BAL and sputum samples.
Conclusions:
- Sulphation pretreatment enables Giemsa staining to detect Pneumocystis cysts, simplifying diagnostic procedures.
- This single-stain method is particularly valuable given the rising prevalence of Pneumocystis carinii pneumonia associated with AIDS.
