The two most common consequences resulting from aspiration are chemical pneumonitis and bacterial aspiration pneumonia. Both entities present with comparable clinical signs and symptoms. In the absence of a reliable clinical or biological marker to differentiate between these two conditions, most patients with suspected aspiration are treated empirically with antibiotics. De-escalation of initial antibiotic treatment is encouraged based on the results of microbiological results, usually performed before starting antimicrobial treatment. However, in most hospitals, 48-72h are required to obtain the results of microbiological cultures, and to de-escalate empirical large spectrum antibiotic treatment.

The use of the Unyvero®, a multiplex PCR-based testing system, for detection of respiratory bacterial pathogens would allow decreasing the percentage of patients with aspiration syndrome who will receive unappropriated antibiotic treatment at Day 3.

Inclusion Criteria:

• presence of risk factors for aspiration :
• known or likely swallowing dysfunction,
• altered consciousness,
• cardiac arrest,
• difficult intubation
• witnessed aspiration
• symptoms and signs suggestive of lower respiratory tract pathology
• temperature ≥38.5°C or <36°C
• leukocyte count ≥10 000/µL or <1500/µL
• purulent sputum or tracheal aspirate.
• new radiographic infiltrate on chest X-ray
• tracheal intubation and mechanical ventilation since less than 48 hours

Exclusion Criteria:

• pregnant women
• refuse to participate to the study
• no informed consent
• documented bacteremia
• septic shock
• severe immunosuppression: leukocytes<1000/L or neutrophils<500/L, chemotherapy during the last 3 months, organ transplant with chronic immunosuppressors use, HIV (CD4<50), and chronic corticosteroid use (>0.5 mg/kg day for at least one month during the last three months).
• moribund patients (SAPS II >90).