Case Report: Early documented infected pancreatic necrosis due to carbapenem-resistant Acinetobacter baumannii and concurrent Enterococcus faecium bacteremia: a salvage regimen with sulbactam-durlobactam and tigecycline

Objective To report an early documented case of culture-proven infected pancreatic necrosis (IPN) caused by carbapenem-resistant Acinetobacter baumannii (CRAB) with concurrent Enterococcus faecium bacteremia, and to describe a salvage regimen combining sulbactam-durlobactam (SUL-DUR) with tigecycline. Methods The clinical data, laboratory findings, and treatment course of the patient were retrospectively described, with a review of the relevant literature. Results A 51-year-old male with severe acute pancreatitis (SAP) developed persistent organ failure, abdominal compartment syndrome, and acute kidney injury requiring continuous renal replacement therapy (CRRT). On day 5, blood cultures grew enterococci (both E. faecalis and E. faecium from a single set), and the patient’s refractory clinical status prompted anti-enterococcal therapy. On day 7, percutaneous drainage first documented IPN caused by CRAB, followed by CRAB bloodstream infection. Because E. faecium is intrinsically resistant to all carbapenems, a carbapenem could not be added as the partner drug for SUL-DUR. Instead, we used SUL-DUR (1 g/1 g q8h, adjusted for CRRT) together with tigecycline. On day 13, after 4 days of SUL-DUR treatment (initiated on day 9), the patient showed clinical improvement and microbiological clearance. On day 19, after completing a 10-day course of SUL-DUR with persistent clinical improvement and two consecutive negative blood cultures, the agent was discontinued. The patient also required neuromuscular blockade for refractory abdominal compartment syndrome and delayed laparoscopic necrosectomy. He was discharged on day 75 in stable condition. Conclusion IPN can be confirmed within the first week of SAP in patients with persistent organ failure and sustained intra-abdominal hypertension, especially in the presence of multidrug-resistant organism colonization. For polymicrobial infections with CRAB and intrinsically carbapenem-resistant E. faecium , the combination of SUL-DUR and tigecycline is a rational alternative when a carbapenem cannot be used.