Microbiological eradication of XDR Acinetobacter baumannii intra-abdominal infection using sulbactam-durobactam: clinical and microbiological outcomes amidst irreversible host comorbidities

Background The management of extensively drug-resistant (XDR) Acinetobacter baumannii (CRAB) in deep-seated infections remains a critical challenge, particularly when compounded by severe host comorbidities. Case presentation We report the case of a 63-year-old male with Stage IV rectal squamous cell carcinoma and Kennedy’s disease (spinal and bulbar muscular atrophy) who developed concurrent pulmonary and intra-abdominal infections with CRAB and carbapenem-resistant Pseudomonas aeruginosa (CRPA) following emergent colorectal surgery. After the failure of an initial salvage regimen comprising polymyxin B, minocycline, and ampicillin-sulbactam, therapy was escalated to sulbactam-durlobactam combined with imipenem-cilastatin. Results Microbiological cure was achieved within 14 days, confirmed by the sterilization of both bronchoalveolar lavage fluid and peritoneal drainage cultures. Despite successful source control and infection eradication, the patient could not be weaned from mechanical ventilation. The convergence of critical illness polyneuropathy/myopathy (CIP/CIM), pre-existing neuromuscular degeneration, and malignant cachexia resulted in fatal multiple organ dysfunction syndrome. Conclusion This case suggests the potential utility of sulbactam-durlobactam in combination with a carbapenem for complicated intra-abdominal infection (cIAI) caused by CRAB, highlighting a successful microbiological outcome. However, it also underscores that microbiological eradication does not invariably translate to clinical survival when overwhelming host factors and irreversible comorbidities dictate the ultimate prognosis.