Effect of different regimens of gut decontamination on bacterial translocation and mortality in experimental acute pancreatitis

Objective: To assess the effect of four regimens of antibiotics (compared with a control regimen of distilled water) given orally on gut decontamination, bacterial translocation, and mortality in acute necrotising pancreatitis in mice. Design: Randomised experimental study. Setting: University hospitals, USA and Italy. Materials: 150 young Swiss Webster mice. Intervention: All mice were fed a diet deficient in choline and supplemented with ethionine. They were then randomised to be given by gavage (36 hours after starting the diet): distilled water (controls, group 1); aztreonam alone (group 2); neomycin, erythromycin, metronidazole (group 3); polymyxin B and amikacin (group 4); polymyxin B, amikacin, amphotericin B (group 5). 20 Mice in each group were treated for 10 days, and the remaining 10 in each group were killed after 3 days. Main outcome measures: Survival, and qualitative and quantitative cultures of the liver, lungs, pancreas and caecum. Results: The best survival rate during the first 7 days was in group 5, but by day 10 there was no difference among the groups. All the antibiotic regimens reduced the number of bacteria in the caecum and all but aztreonam alone (group 2) reduced the rate of translocation of both Gram negative and Gram positive bacteria to all organs studied. Translocation of yeast occurred in those animals in groups 2, 3, and 4 in which there was overgrowth of fungi in the caecum. Conclusion: Gram negative and Gram positive organisms and fungi may have an important role in infective morbidity and mortality in acute pancreatitis, and selective decontamination with polymyxin B, amikacin, amphotericin B reduced the incidence of translocation related infections and early mortality in mice with acute necrotising pancreatitis.