title: Role of the macrophage in the translocation of intestinal bacteria.
abstract: To clarify the role of the macrophage in the translocation of intestinal bacteria, groups (n = 10) of Swiss Webster mice (Immunocompetent) and C3H/HeJ mice (macrophage defective) were given bacitracin/streptomycin in their drinking water to eliminate the majority of the intestinal microflora. These mice were then "monoassociated" with a streptomycin-resistant strain of Escherichia coli. Forty-eight hours later, E coli was present in all animals at a concentration of 10(11)/g of cecum. In four separate experiments, E coli was recovered from 100% of the mesenteric lymph nodes (MLNs) of the immunocompetent Swiss Webster mice and from 10%, 40%, 30%, and 50% of the MLNs of macrophage-defective C3H/HeJ mice. Swiss Webster mice were then similarly monoassociated by antibiotic decontamination followed by administration of antibiotic-resistant, fluorescein-labeled E coli in their drinking water; cohort groups of mice were given fluorescein-labeled latex beads (1 micron in diameter) in their drinking water. Two, four, and 11 days later, the MLNs were removed and single cell suspensions were analyzed in the fluorescence-activated cell sorter. The fluorescein label was detected exclusively in the macrophage (esterase-positive) population. These results support the hypothesis that intestinal macrophages may play a key role in the transport of intestinal particles (including bacteria) into extraintestinal sites.
mesh_terms: D000818:Animals; D018407:Bacterial Physiological Phenomena; D002432:Cecum / Q000382:microbiology; D004926:Escherichia coli / Q000502:physiology; D005260:Female; D005452:Fluoresceins; D006801:Humans; D007422:Intestines / Q000382:microbiology*; D008198:Lymph Nodes / Q000382:microbiology; D008264:Macrophages / Q000502:physiology*; D051379:Mice; D008809:Mice, Inbred C3H; D010865:Pilot Projects; D013997:Time Factors
chemical_list: D005452:Fluoresceins