Frederick A. Klipstein

Enterotoxigenic Intestinal Bacteria in Tropical Sprue: II. Effect of the bacteria and their enterotoxins on intestinal structure

Randomly selected strains of the predominant coliform bacteria, three serotypes of Klebsiella pneumoniae and a strain of Enterobacter cloacae , isolated from each of 4 Puerto Ricans with tropical sprue, were examined for their effect on intestinal structure in the ileal loop model of 34 rabbits. The viable bacteria did not evoke a fluid response, invade the mucosa, or cause changes in villus architecture, but they did result in the formation of a luminal exudate consisting of mucin, necrotic epithelial cells, bacteria, and epithelial cell enzymes. Cell-free broth filtrates of bacterial growth of all four strains produced an increasingly positive fluid response from 2 to 18 hr and progressively more severe structural changes which consisted of shortening and blunting of the villi, infiltration predominantly by mononuclear cells, and submucosal congestion. Equally hyperosmolar control preparations of broth medium without bacterial growth and cell-free broth filtrates of a nontoxigenic strain of Escherichia coli failed to induce these abnormalities. These observations indicate that the coliform bacteria tested elaborate a toxic product, presumably an enterotoxin, which produces structural and functional changes of the intestinal mucosa resembling those present in tropical sprue.

Intestinal structure and function in neoplastic disease.

Intestinal structure and function have been evaluated in 24 patients who had neoplastic disease arising outside the gastrointestinal tract. The gross appearance of the jejunal mucosa was normal in all 18 biopsy specimens obtained; on histologic examination, villous structure was normal in 15 and slightly blunted in 3, one of which showed synechia formation, and another increased lymphocytic infiltration of the lamina propria. Fecal fat excretion was normal in 20, and borderline in 1 patient. The urinary excretion of xylose was subnormal in 14 subjects; however, peak serum concentrations were normal in all 24. The absorption of folic acid was normal in 19, and borderline in 3 patients. The urinary excretion of60CoB12 was subnormal in 12 of 18 persons tested. These observations indicate that, with the possible exception of vitamin B12 absorption, abnormalities of small intestinal structure and function are rare in persons with extragastrointestinal neoplasms. Weight loss in these individuals could be accounted for by reduced caloric intake, secondary to anorexia in nearly all instances.