Development of a new Acinetobacter baumannii pneumonia rabbit model for the preclinical evaluation of future anti-infective strategies

Carbapenem-resistant Acinetobacter baumannii (CRAB) is a growing cause of hospital-acquired pneumonia (HAP). Preclinical large models are needed to predict the efficacy and resistance profile of anti-infectives and mimic human treatment. An experimental pneumonia model was developed in immunocompromised rabbits, receiving a 48-hour human-simulated regimen. The efficacy of meropenem, rifampin, or a combination of both was assessed in rabbits infected with the ATCC 17978 reference strain or CRAB Turc 2 clinical strain. Meropenem showed a strong pulmonary bacterial reduction, while high rifampin dosage led to high-level resistant mutants in 80%–100% of animals. The model represents an innovative tool for evaluating new or existing therapies and providing data on resistance pharmacodynamic targets.