Inoculation of pleural fluid in blood culture bottles could be a routine practice in pleural infection

Abstract

Background Worldwide, pleural infections are becoming more common. Overuse of empirical antibiotics has been linked to longer hospital stays and higher death rates, causing the emergence of antibiotic-resistant pathogens. So, proper care requires the identification of the pathogenic bacteria using pleural fluid culture. In addition to normal culture, pleural fluid inoculation in blood culture bottles enhances the proportion of patients with detectable infections in less time. Aim To assess whether inoculating pleural fluid into a blood culture bottle will increase the yield of isolated pathogens compared to routine culture techniques in evaluating pleural infection. Also, to compare the time of pathogen detection when comparing the detection by blood culture bottle versus the routine microbiological culture technique. Recognize the distribution of isolated bacteria from our center and their susceptibility profile to different antibiotics and predict the most effective empirical antibiotics. Patients and methods Cross-sectional analytical prospective study conducted at the Department of Pulmonology and Clinical Pathology in Cairo University Hospitals. It included 70 patients with infected pleural effusion. Under ultrasound supervision, pleural fluid was extracted and transported to the laboratory for routine microbiological culture. At the same time, an automated blood culture bottle was inoculated with 5–10 ml to be incubated. All the detected pathogens were identified and tested for antimicrobial susceptibility according to CLSI. Results The mean age of our patients was 47.1 ± 15.6 years. Empyema was documented in 16 (22.9%) of our patients, whereas 54 (77.1%) had exudative pleural effusion. Positive aerobic infection in blood culture bottle was seen in 37 patients, compared to 21 patients in direct pleural culture. A statistically significant difference was found between the culture positive rate in aerobic blood culture bottles and direct pleural culture (P=0.001). Conclusion Blood culture bottle inoculation of infected pleural fluid increases the sensitivity of microbial yield in a shorter time than standard culture.