THE PRIMARY SITE OF BACTERIAL TRANSLOCATION

Objective: To establish the primary anatomic site of bacterial translocation in the intestinal tract. Design: Prospective randomized experimental trials. Setting: Laboratory. Materials: Hartley guinea pigs. Interventions: In guinea pigs, 10-cm closed loops of upper jejunum, distal ileum, or proximal colon were created. The animals then received intraluminal injections of Escherichia coli labeled with radioactive carbon (C-14) before a 50% full-thickness burn was inflicted. Four hours after the burn injury, the animals were killed, and the intestinal loops, mesenteric lymph nodes, spleen, liver, and lung were harvested. Intestinal loops were irrigated and then treated with ethylenedinitroilotetraacetic acid to separate the enterocytes and colonocytes from the lamina propria. Radionuclide counts were determined in the effluents, the enterocytes (or colonocytes), lamina propria, and other organs. Colony-forming units of E coli were also determined in mesenteric lymph nodes, spleen, liver, and lung. Measurements and Main Results: No significant 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 counts in the mesenteric lymph nodes, liver, spleen, and lung related to the type of loop, but more viable bacteria were recovered when bacteria 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.