Case Report: Diagnosis and management of severe pneumonia caused by complex mixed infection with multidrug-resistant bacteria and fungi after liver retransplantation.

Background: Patients undergoing liver retransplantation remain in a prolonged immunosuppressed state and are at high risk for complex mixed infections caused by multidrug-resistant organisms (MDROs) and invasive fungi. Under such circumstances, accurately identifying the predominant pathogens and developing a treatment strategy that balances anti-infective therapy with organ function preservation remain major challenges in current clinical practice. Case presentation: This article reports the case of a 59-year-old male patient who developed severe pneumonia, septic shock, and multiple organ failure following liver retransplantation. Etiological investigations identified carbapenem-resistant Conclusions: For complex mixed infections following liver retransplantation, continuous evaluation of pathogen profiles, immune status, and organ function is critical for guiding individualized treatment strategies. This case highlights that, while potent targeted anti-infective therapy may be life-saving, close monitoring and prompt intervention for treatment-related adverse events and complications are equally essential to achieve a balance between therapeutic benefit and clinical risk under critical conditions.