Combination of a multiplex pneumonia panel and Gram staining for antimicrobial selection to treat lower respiratory tract infection.

Aim: This study aimed to examine the utility of simultaneously performed the Film Array pneumonia panels (pneumonia panels) and Gram staining with the same specimens and evaluate their effect on antimicrobial selection.

Methods: This prospective study, conducted from April 2022 to January 2023, enrolled adult patients with pneumonia, including those with ventilator-associated pneumonia (VAP). Specimens obtained at the time of sputum culture were tested using Gram staining and the pneumonia panel. The patients' characteristics and pneumonia panel results were assessed. We also evaluated the selection of antimicrobial agents for drug-resistant bacteria detected by the pneumonia panel.

Results: This study comprised 39 patients: 25 patients (64.1%) underwent intubation, including 7 (17.9%) patients with VAP. Most tests were performed at the time of admission, while some were performed during hospitalization. Good quality sputum was obtained from intubated patients. The pneumonia panel detected drug-resistant bacteria in 12 cases. Six patients required antimicrobial escalation, while the antimicrobial regimen remained unchanged for 2 patients in whom Pseudomonas aeruginosa was detected and had already received meropenem. The attending physician did not change the antimicrobials, considering the results of Gram staining and the patient's general condition in 4 patients.

Conclusions: The pneumonia panel might be useful for detecting drug-resistant organisms at an early stage. It may be important to take the Gram staining results and the patient's condition into account with pneumonia panel for appropriate antibiotic prescription.