Inclusion Criteria:  All adult patients mechanically ventilated for at least 48 hours in Respiratory ICU were included in the study.  who had:  Clinically suspected VAP according to simplified Clinical Pulmonary Infectious Score exceeding 6.  Or new or extension of a radiological image with at least two of the following clinical criteria:  Body temperature ≥ 38.5 ° C or <36 ° C. Leukocytes> 10 * 103 / ml or <4 * 103/ ml or > 10% immature cells (in the absence of other known causes). Purulent tracheal secretions. Hypoxemia with PaO2 <60 mmHg or a PaO2 / FiO2 <300.  Exclusion Criteria:  Patients with diagnosis of community acquired pneumonia or hospital acquired pneumonia before starting of mechanical ventilation. Patients who are contraindicated for bronchoscopy