Objective: Pneumocystis jirovecii is among the important causative agents of pneumonia especially in immunocompromised individuals. In our study, we aimed to evaluate the etiology of pneumonia using bronchoalveolar lavage samples in terms of Pneumocystis pneumonia (PCP) and to identify other underlying agents.

Method: We analyzed bronchoalveolar lavage samples by May Grünwald/Giemsa, modified toluidine blue, immunofluorescent antibody staining and real-time polymerase chain reaction method, and investigated their roles in the diagnosis of PCP. Appropriate methods were also used to identify bacteria, fungi, Mycobacterium tuberculosis and Cytomegalovirus.

Results: In this study,100 patients (32 females and 68 males) aged between 18-90 (mean age 53.02) years were included in the study.. In 17 patients any underlying disease was not detected, and bronchoscopy was performed only with a preliminary diagnosis of pneumonia, and in only one patient pmeuımocystitis pneumonia-positivity was detected by real-time polymerase chain reaction method. When all patients were evaluated, an infectious agent was found in 33% of them.

Conclusion: As a result, in this study PCP rate was found to be low with staining methods and real-time polymerase chain reaction. Higher rates can be obtained in studies with greater number of patients. However, bronchoalveolar lavage samples are important in identifying etiology in patients with poor general condition.