THE PRIMARY SITE OF BACTERIAL TRANSLOCATION

Objective: To establish the primary anatomic site of bacterial translo cation in the intestinal tract. Design: Prospective randomized experim ental trials. Setting: Laboratory. Materials: Hartley guinea pigs. Int erventions: In guinea pigs, 10-cm closed loops of upper jejunum, dista l ileum, or proximal colon were created. The animals then received int raluminal injections of Escherichia coli labeled with radioactive carb on (C-14) before a 50% full-thickness burn was inflicted. Four hours a fter the burn injury, the animals were killed, and the intestinal loop s, mesenteric lymph nodes, spleen, liver, and lung were harvested. Int estinal loops were irrigated and then treated with ethylenedinitroilot etraacetic acid to separate the enterocytes and colonocytes from the l amina propria. Radionuclide counts were determined in the effluents, t he enterocytes (or colonocytes), lamina propria, and other organs. Col ony-forming units of E coli were also determined in mesenteric lymph n odes, spleen, liver, and lung. Measurements and Main Results: No signi ficant differences were noted in the radionuclide counts in the lamina propria and epithelial cell fraction related to the type of loop. In addition, no significant differences were noted in the radionuclide co unts in the mesenteric lymph nodes, liver, spleen, and lung related to the type of loop, but more viable bacteria were recovered when bacter ia were injected into the jejunal loop. Conclusions: Translocation of bacteria occurred with similar intensity throughout the gut, but more bacteria were killed in the process of translocation across the lower part of the intestinal tract.