Microbial Detection in Community Acquired Pleural Space Infection Using the BioFire Joint Infection Panel and Individual PCR Assays

Objective New insights into community acquired pleural infection microbiology may enable development of more rapid and accessible diagnostics that can streamline treatment. This study systematically compared molecular approaches for pathogen detection in pleural fluid from patients with such infections. Considering the need for rapid results with minimum hands-on time and test complexity, off-label use of the cassette-based, random-access BIOFIRE® Joint Infection (JI) Panel (bioMérieux) with and without supplementary in-house PCRs was evaluated. Methods Pleural fluids from 162 subjects from the Mayo Clinic (Rochester, Minnesota) and Haukeland University Hospital (Bergen, Norway), where molecular tests are routinely used for analyzing pleural fluid, were studied. The performance of the BIOFIRE JI Panel was compared to 16S ribosomal RNA gene PCR followed by Sanger and next-generation sequencing (16S rRNA gene PCR/sequencing), an in-house PCR panel specifically designed for pleural space infections, and culture. Main Results The BIOFIRE JI Panel supplemented with three in-house PCRs targeting Fusobacterium nucleatum group, Streptococcus intermedius/constellatus and Aggregatibacter aphrophilus detected 96.8% of pleural infections, providing complete microbial profiles in 70.8%. In comparison, the detection rate of 16S rRNA gene PCR/sequencing was 92.2%, providing complete microbial profiles in 87.0%. Culture detected bacteria in only 31.9% of pleural fluids, providing complete microbial profiles in 15.3%. Conclusions These results underscore the importance of molecular approaches in diagnosing pleural space infections and demonstrate the feasibility of panel-based PCR-based diagnostics for these sometimes-complex infections. The BIOFIRE JI Panel, designed for testing synovial fluid, could be modified to provide a useful diagnostic for testing pleural fluid.