Objective: Despite the current use of effective antibiotics and vaccines, community-acquired pneumonia is still an infection with high morbidity and mortality. Therefore, identifying common pathogens is of epidemiological importance.

The aim of our study is to examine the distribution of bacterial agents in patients with pre-diagnosis of lower respiratory tract infection who applied to various outpatient clinics and services of our hospital over a threeyear period.

Methods: The results of the samples taken from patients presenting with respiratory tract infection complaints and sent for the study of the respiratory tract bacterial agents panel were retrospectively examined from the hospital information management system between 01.04.2021–31.03.2024 in Necmettin Erbakan University Medical Microbiology Laboratory. Respiratory tract samples were investigated using a commercial kit by multiplex real-time polymerase chain reaction (PCR) method for the detection of bacterial agents.

Results: In our study, the rate of detecting bacterial agents in at least one sample was 46.7%. The incidence of the causative agent is respectively S. pneumoniae (35.4%), H. influenzae (20.1%), M. catarrhalis (14.2%) and L. pneumophila (4%). No positivity was detected in Mycoplasma pneumoniae, Chlamydia pneumoniae bacteria. M. catarrhalis was found to be significantly more common in patients with a lower age group (p=0.017). There was no significant seasonality in bacteria other than M. catarrhalis (p=0.0011).

Conclusion: Traditional methods such as culture and serology are not always sufficient to detect respiratory pathogens. The common use of multiplex PCR is beneficial because it detects polymicrobial agents and atypical bacteria and provides rapid and reliable results.