Lethal burn-induced bacterial translocation: role of genetic resistance.

Since genetic factors may influence outcome after trauma or during infection, the current experiments were performed to examine the resistance of three genetically different mouse strains to burn-induced bacterial translocation. Outbred ICR, inbred Balb/c, and inbred C57/B1 mice, with a normal or disrupted (monoassociated with Escherichia coli C25) GI tract microflora, were subjected to sham or actual 25% body burns. In Balb/c, but not ICR mice, replacing the normal intestinal microflora with E. coli C25 converted the thermal injury from a nonlethal (0% mortality) to a lethal (68% mortality) injury. The increased mortality of the burned Balb/c mice monoassociated with E. coli C25 was associated with a higher incidence (p less than 0.05) and magnitude (p less than 0.05) of E. coli C25 translocation from the GI tract. The C57/B1 mice were intermediate between the Balb/c and ICR strains, in that C57/B1 mice monoassociated with E. coli C25 had a higher mortality and greater E. coli C25 translocation than mice with a normal microflora after thermal injury. Thus the composition of the intestinal microflora as well as the genetic background of the host influence the susceptibility of the host to burn-induced bacterial translocation and survival.