Frequency and time course of pancreatic and extrapancreatic bacterial infection in experimental acute pancreatitis in rats.

BACKGROUND: Infectious complications in severe pancreatitis are the main factors determining clinical course and outcome. The taurocholate model for acute necrotizing pancreatitis was evaluated for frequency and time course of pancreatic and extrapancreatic bacterial infection.
METHODS: Sixty-five male Wistar rats were divided into 5 groups of 13 animals each. Specimens for bacteriologic examination were taken, and pancreatitis was induced by intraductal infusion of 3% taurocholate under sterile conditions. Animals were killed 8, 16, 24, or 32 hours thereafter, and bacteriologic examination was performed. A control group of animals with intraductal infusion of 0.9% saline solution were killed after 32 hours.
RESULTS: There was no significant pancreatic infection in the control group and in the 8-hour group (1 of 13 rats). Sixteen and 24 hours after induction of pancreatitis, infection and inflammation of the pancreas were found in 77% (10 of 13 rats), and after 32 hours pancreatic infection occurred in 69% (9 of 13 rats). Extrapancreatic bacterial infection after 16 hours occurred in the liver (62%), spleen (62%), and mesenteric lymph nodes (46%). Bacteria infecting the pancreas reflected the bacterial spectrum of the large bowel and terminal ileum before induction of pancreatitis (Escherichia coli [77%], Proteus [43%], Enterococcus [37%], and Staphylococcus [23%]).
CONCLUSIONS: Pancreatic infection is an early and frequent finding in the taurocholate model of acute necrotizing pancreatitis. Infection occurs between 8 and 16 hours after induction of pancreatitis. The source of infecting bacteria seems to be the large bowel or the terminal ileum. We present a useful model of severe pancreatitis in which to study bacterial translocation, the further route of spread, and therapeutic approaches.