Salmonella typhi infection in walled-off pancreatic necrosis following recurrent acute pancreatitis: a rare case report and review of pathogenesis

Abstract

Infected pancreatic necrosis is a serious complication of acute pancreatitis, typically caused by enteric Gram-negative organisms. The isolation of atypical pathogens, particularly Salmonella enterica serovar Typhi, from pancreatic collections is exceedingly rare and poses diagnostic and therapeutic challenges. A 28-year-old male with alcohol-related recurrent acute pancreatitis presented with abdominal pain, vomiting, and high-grade fever. He had been initially managed at an outside facility and was referred approximately four weeks after symptom onset with clinical deterioration. Imaging revealed a large necrotic pancreatic collection involving the body and tail, with internal debris and features suggestive of infection. The computed tomography severity index (CTSI) was 8/10, and the collection was classified as infected walled-off necrosis. Given persistent sepsis and unfavorable anatomy for endoscopic drainage, a minimally invasive step-up approach was adopted, and CT-guided percutaneous catheter drainage (PCD) was performed. Microbiological analysis of the drained fluid revealed growth of Salmonella enterica serovar Typhi, sensitive to third-generation cephalosporins and azithromycin but resistant to fluoroquinolones. Blood cultures were not obtained at initial presentation. Targeted intravenous antibiotic therapy was initiated based on culture sensitivity, resulting in progressive clinical improvement. The patient stabilized with resolution of fever and reduction in drain output and was discharged with the catheter in situ for follow-up. The presence of Salmonella typhi in pancreatic necrosis is rare, with only a limited number of cases reported in the literature. Possible mechanisms include hematogenous dissemination during transient bacteremia and bacterial translocation in the setting of necrotic pancreatic tissue. This case highlights the importance of differentiating true infection from contamination and underscores the role of culture-directed therapy. It also reinforces the effectiveness of a tailored, minimally invasive step-up approach in managing infected walled-off necrosis. Atypical pathogens such as Salmonella typhi may rarely complicate pancreatic necrosis and should be considered in patients with persistent sepsis. Integration of microbiological data with clinical and radiological findings is essential for accurate diagnosis and targeted management. Early recognition and individualized intervention strategies can significantly improve patient outcomes.