Antimicrobial and Antibacterial Agents

Objective: To define the most common pathogens in patients with pleural empyema and find the specific antibiotics in order to treat patients more effectively.

Method: In this prospective analytic study all patients who admitted in Dr. Masih Daneshvari Hospital with the confirmed diagnosis of pleural empyema from April 2017 to 2018 were enrolled to our study. Sample of pleural fluid was sent to laboratory for Gram staining and aerobic and also anaerobic culture.

Results: 48 patients with pleural empyema including 40 men and 8 women with the mean age of 43.29 years (range of 5 to77) were studied. Cultures were positive in 6 patients (12.5%); a total of 4 microorganisms were isolated. Aerobic Gram-negative organisms were the most common bacteria in positive culture effusions (66.66%). In this study there were only 6 patients with positive cultures (12.5%), Two patients had Pseudomonas aeruginosa, Acinetobacter baumannii was cultured in two patients, Enterococcus sp., in one

patient and Streptococcus non group was cultured in one patient. Nine patients had positive Gram stain but there was not any growth in their cultures (all of them had rare Gram-positive cocci and two of them also had rare Gram-negative bacilli). The rest of the patients (33/48-68.75%) had negative Gram stain and cultures.

Conclusion: The number of patients who had positive culture was less than expected. We think that there might be a problem in sample collecting, sample transferring, culture providing or the improper usage of broad spectrum antibiotics before referring to hospital and taking the samples.