Bacterial translocation in D-galactosamine-treated rats in a burn model

Bacteria and endotoxins can pass through the gut barrier under certain conditions. This process of bacterial translocation (BT) may occur after thermal injury in animals and is thought to play a role in the pathogenesis of septic complications in severely burned patients. The current study was performed to determine the role of endotoxin-related cytokines in the pathogenesis of burn-induced BT. Wistar rats were used in which enhanced sensitivity to TNF/LPS reactions was achieved by treatment with galactosamine (GalN). The GI tracts of these rats were antibiotic decontaminated with oral bacitracin and neomycin and were colonized with a neomycin resistant (NR)-Escherichia coli strain. The rats were divided into four groups, 30 per cent TBSA scald with GalN (Burn+GalN) pretreatment; 30 per cent TBSA scald without GalN (Burn); or sham injury with (GalN) and without GalN (Sham) pretreatment. On day 2, the animals were killed and liver, spleen, lung, heart and the peritoneal cavity were cultured. Blood samples were taken and the concentrations of LPS, TNF, IL-6 and ALAT were determined. Mortality was significantly increased in the Burn+GalN group compared to the other groups. In all groups, the incidences of BT were increased compared to the sham-treated group, although BT was most pronounced in the Burn+GalN group. In the latter group it was accompanied by highly elevated IL-6 and ALAT levels. The results of this study suggest that endotoxin mediators like TNF and IL-6 could play a role in the phenomenon of BT and that the function of the liver is an important clearing mechanism.