Background: Ventilator-associated pneumonia (VAP) is a common nosocomial infection in intensive care units (ICUs), associated with increased morbidity, mortality, and healthcare costs. The microbiological profile and antimicrobial resistance patterns of VAP vary across regions, necessitating local data for effective management. Objectives: To determine the microbiological profile of ventilator-associated pneumonia and to assess the antimicrobial susceptibility patterns of the isolated pathogens in a tertiary care hospital in North India. Methods: This prospective observational study was conducted in the ICU of a tertiary care hospital from August 2015 to December 2015. A total of 60 adult patients who were mechanically ventilated for more than 48 hours and clinically suspected of VAP were included. Respiratory samples were collected and processed using standard microbiological techniques. Identification of organisms and antimicrobial susceptibility testing were performed according to established guidelines. Data were analyzed using SPSS version 20.0, and statistical significance was set at p < 0.05. Results: The majority of patients were males in the age group of 41–60 years. Gram-negative organisms predominated, with Acinetobacter baumannii (33.3%) being the most common isolate, followed by Pseudomonas aeruginosa (23.3%) and Klebsiella pneumoniae (20.0%). Among Gram-positive organisms, Staphylococcus aureus accounted for 13.3% of cases, with a high proportion of methicillin-resistant strains (62.5%). High resistance rates were observed against ceftriaxone (76.9%) and ciprofloxacin (69.2%), while relatively lower resistance was noted with piperacillin-tazobactam (34.6%) and imipenem (30.8%). A significant association was found between prolonged duration of ventilation and the occurrence of multidrug-resistant organisms (p = 0.03). Conclusion: The study highlights the predominance of multidrug-resistant Gram-negative organisms in VAP and emphasizes the importance of continuous surveillance, rational antibiotic use, and stringent infection control practices. Institution-specific antibiograms are essential for guiding empirical therapy and improving patient outcomes.

Ventilator-associated pneumonia; Acinetobacter baumannii; antimicrobial resistance; ICU infections; multidrug-resistant organisms; India