Objective To evaluate the clinical efficacy and safety of sulbactam-durlobactam in the treatment of pulmonary infection caused by extensively drug-resistant Acinetobacter baumannii (XDR-AB) after liver transplantation.

Methods A retrospective analysis was performed on the data of 3 liver transplant recipients admitted to the First Affiliated Hospital of Xi'an Jiaotong University from May to December 2025, who developed postoperative XDR-AB pulmonary infection and received sulbactam-durlobactam-based anti-infective therapy. Clinical data, clinical efficacy, microbiological response, safety and outcomes were analyzed.

Results All isolated strains were XDR-AB producing OXA-23 carbapenemase, and in vitro antimicrobial susceptibility testing showed sensitivity to sulbactam-durlobactam. After treatment with sulbactam-durlobactam, all 3 recipients achieved clinical cure and microbiological eradication, with a treatment course of 6-8 days and pathogen clearance time of 3-6 days. Septic shock was effectively controlled in all recipients, who were successfully weaned from mechanical ventilation, and oxygenation index and organ function scores were significantly improved. No definite nephrotoxicity or other severe adverse reactions related to sulbactam-durlobactam were observed during treatment, and the 30-day all-cause fatality was 0. Two critically ill recipients achieved rapid microbiological clearance after combined nebulized phage therapy.

Conclusions Sulbactam-durlobactam-based regimen shows favorable efficacy and safety in liver transplant recipients with postoperative XDR-AB pulmonary infection, and has a promising clinical application prospect.