# The Resistance Paradox in COVID-19 Ventilator-Associated Pneumonia: A Retrospective Study on Rapid Molecular Stewardship

## TL;DR

This study found that ventilator-associated pneumonia in COVID-19 patients shows higher antibiotic resistance and benefits from faster molecular testing.

## Contribution

The study identifies a distinct antimicrobial resistance profile in VAP-COVID and evaluates rapid molecular diagnostics for faster results.

## Key findings

- VAP-COVID patients had higher resistance to carbapenems and fluoroquinolones compared to non-COVID-VAP patients.
- POC-PCR significantly reduced diagnostic turnaround time compared to standard culture methods.
- VAP-COVID patients had lower pleural effusion and higher neutrophil-to-lymphocyte ratios.

## Abstract

Background/Objectives: The COVID-19 pandemic complicated the diagnosis of Ventilator-Associated Pneumonia (VAP), leading to empiric antibiotic overuse due to the difficulty in distinguishing viral progression from bacterial superinfection. However, it remains unclear whether COVID-19-associated VAP displays a distinct antimicrobial resistance profile compared to classical VAP. Methods: This monocentric, retrospective cohort study primarily investigated differences in clinical phenotypes and antibiotic resistance profiles between patients with VAP-COVID (n = 26) and non-COVID-VAP (n = 26). Logistic regression was used to identify factors associated with the COVID-19 phenotype and predictors of antimicrobial resistance. As a secondary objective, we evaluated the diagnostic efficacy of a multiplex Point-of-Care PCR (POC-PCR) system (n = 22) compared to standard culture (n = 26) regarding turnaround time and resistance detection. Results: Patients with VAP-COVID exhibited significantly higher resistance rates to carbapenems (76.9% vs. 50%, p = 0.04) and fluoroquinolones (88.5% vs. 61.5%, p = 0.02) despite fewer traditional risk factors at admission. The clinical profile of the VAP-COVID group was distinguished by a significantly lower incidence of parapneumonic pleural effusion (19.2% vs. 84.6%, p < 0.001) and a higher median Neutrophil-to-Lymphocyte Ratio (41.36 vs. 9.63, p < 0.001). Regarding diagnostic speed, POC-PCR significantly reduced the time to result validation compared to standard culture (~1 h vs. ~62.5 h, p < 0.001). Conclusions: VAP in COVID-19 patients presents a distinct microbiological profile characterized by higher antimicrobial resistance. In this context, the integration of rapid molecular diagnostics may support earlier microbiological guidance compared to standard methods.