Escherichia coli is the most commonly isolated organism in infected pancreatic necrosis due to its predominance as a gut flora and its translocation from the intestines to the necrotic pancreatic tissue. The pancreas, when necrotic, provides a favorable environment for these gram-negative enteric bacteria to proliferate. Early identification and targeted antibiotic therapy against E. coli are crucial to reduce morbidity. Surgical debridement or minimally invasive drainage is often needed once infection is established. Understanding the microbial profile guides appropriate antimicrobial coverage in managing infected pancreatic necrosis.

Reference: Sabiston Textbook of Surgery, 21st Edition.