Background: Low respiratory tract infections (LRTIs) are common and serious nosocomial infections in ICUs and are responsible for longer hospital stay, higher costs, and greater mortality. Accurate and timely microbiologic diagnostic approaches for LRTIs are urgently needed to guide targeted therapeutic choices and reduce the impact of ineffective empiric antibiotic regimens and the overuse of antibiotics. We carried out a multicentric study aimed to evaluate the performance of the Investigational Use Only (IUO) BIOFIRE® FILMARRAY® Pneumonia Panel (PNplus Panel). This syndromic panel allows the rapid detection (about 1 hour), directly from respiratory samples, of 34 targets for the most common bacterial, viral, and atypical bacterial pathogens responsible for LRTIs.
Materials/methods: The study was performed on 475 low respiratory samples (sputum, BAS, BAL and ETA) from 8 microbiology laboratories in Italy. All samples were simultaneously analysed with PNplus Panel and the standard of care (SoC) consisting in culture for bacteria detection and sometimes in other molecular methods for virus/atypical bacteria detection.
Results: Three samples resulted invalid by PNplus Panel and were excluded from the analysis. A total of 52 samples resulted negative for both PNplus Panel and SoC. From the 420 remaining samples, 745, 84 and 15 bacterial, viral, and atypical bacterial target identifications were obtained, respectively. Correspondences between PNplus Panel and SoC were as follow: 468 bacterial targets were identified by both PNplus Panel and SoC, 251 by PNplus Panel only, and 26 just by SoC; 19 viral targets were detected by both methods, 63 by PNplus Panel only (not always investigated by SoC) and 2 solely by SoC; 11 atypical bacterial targets, were identified by both methods, 3 just by PNplus Panel and 1 was revealed by SoC only.
Conclusions: PNplus Panel showed excellent performances in detecting almost all the main respiratory pathogens and in revealing additional pathogens. Therefore, PNplus Panel is a promising test for the rapid microbiological diagnosis of respiratory infections and could have a positive impact on patient outcome and antibiotic stewardship. The absence of some targets in the panel and the epicritical value of PNplus Panel additional detections should be considered.