# Application of Real-Time PCR Syndromic Panel on Lower Respiratory Tract Samples: Potential Use for Antimicrobial De-Escalation

## TL;DR

This study shows that using a real-time PCR test on respiratory samples helps reduce unnecessary antibiotic use in pneumonia patients.

## Contribution

The study demonstrates the clinical utility of a molecular syndromic panel for antimicrobial de-escalation in pneumonia.

## Key findings

- Antimicrobial therapy was modified in 47.1% of patients after molecular testing.
- Unnecessary antibiotics were discontinued or avoided in 35% of patients.
- The molecular panel helped guide feasible de-escalation in clinical practice.

## Abstract

Molecular methods allow for a rapid identification of the main causative agents of pneumonia along with the most frequent resistance genes. Prolonged broad-spectrum antibiotic therapy without microbiological evidence of infection drives antimicrobial resistance. We evaluated if the result provided by the molecular method is helpful for antimicrobial de-escalation. All respiratory samples collected and directly processed via Real-Time PCR from patients with suspected pneumonia, of whom clinical data were available, were included in this study. In 82 patients out of a total of 174 (47.1%), antimicrobial therapy was modified after the molecular test, and in 28/82 (34.1%), antimicrobial de-escalation was carried out. Among the 92 patients in whom therapy was not modified, 33 (35.9%) were did not receive any antimicrobial therapy before the molecular test and no antibiotics were prescribed after the test. Therefore, in 61 (28 + 33) out of the 174 (35%) patients, unnecessary antimicrobials were discontinued or avoided. The syndromic panel used at our institution can be of help in better choosing when empiric antibiotic de-escalation therapy could be feasible.