Pleural fluid PCR method for detection of Staphylococcus aureus, Streptococcus pneumoniae and Haemophilus influenzae
G Eda Utine1, Ahmet Pinar, Uğur Ozçelik
1Department of Pediatrics, Division of Chest Diseases, Hacettepe University, Faculty of Medicine, Sihhiye/Ankara, Turkey. geutine@hacettepe.edu.tr
Background:
Parapneumonic effusions cause significant morbidity and mortality despite current developments in diagnostic and therapeutic approaches. Causative microorganisms may remain unidentified in a significant number of patients by cultures and Gram smears. Polymerase chain reaction (PCR) is a molecular technique for the detection of causative bacteria; however, its efficiency in pleural fluids is less known.
Objectives:
The present study was performed to compare the efficiency of PCR in the detection of the three most common organisms (Staphylococcus aureus, Streptococcus pneumoniae and Haemophilus influenzae) with conventional methods.
Methods:
Twenty-eight consecutive patients with parapneumonic pleural effusions were studied. On admission, pleural fluid samples were obtained for Gram staining, routine culture and PCR analysis for S. aureus, S. pneumoniae and H. influenzae.
Results:
PCR analysis allowed detection of 11 microorganisms in 10 patients (35.7%), whereas pleural fluid cultures detected the etiological agent in only 2 (7.1%). S. pneumoniae was the most frequent agent.
Conclusions:
Pleural fluid cultures may have low diagnostic yields, partly due to prior antibiotic use. Pleural fluid PCR analysis may improve the etiologic diagnosis in parapneumonic pleural effusions, with technical advances leading to higher yields than obtained in this study.
Insights
Polymerase chain reaction (PCR) significantly improves the detection of bacteria in parapneumonic effusions compared to traditional cultures. This molecular method offers higher yields for identifying causative agents in pleural fluid infections.
Area of Science:
- Infectious Diseases
- Microbiology
- Pulmonary Medicine
Background:
- Parapneumonic effusions are a significant cause of illness and death.
- Conventional diagnostic methods like Gram stains and cultures often fail to identify causative microorganisms.
- Polymerase chain reaction (PCR) is a sensitive molecular technique with less understood efficacy in pleural fluid analysis.
Purpose of the Study:
- To evaluate the diagnostic efficiency of PCR for common pathogens in parapneumonic effusions.
- To compare PCR performance against conventional methods (Gram stain, culture) for Staphylococcus aureus, Streptococcus pneumoniae, and Haemophilus influenzae.
Main Methods:
- Analysis of pleural fluid samples from 28 patients with parapneumonic effusions.
- Samples underwent Gram staining, routine culture, and PCR for S. aureus, S. pneumoniae, and H. influenzae.
Main Results:
- PCR detected microorganisms in 10 patients (35.7%), identifying 11 pathogens.
- Conventional cultures identified the etiological agent in only 2 patients (7.1%).
- Streptococcus pneumoniae was identified as the most frequent causative agent.
Conclusions:
- Low diagnostic yields of pleural fluid cultures may be attributed to factors like prior antibiotic administration.
- Pleural fluid PCR analysis demonstrates potential to enhance etiologic diagnosis in parapneumonic effusions.
- Further technical advancements in PCR could lead to even higher detection rates.
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