Enterotoxigenic Intestinal Bacteria in Tropical Sprue

Bacterial growth was seen in cultures of fasting or postprandial midjejunal aspirates from 10 of 11 patients with tropical sprue; 2 of 4 healthy North Americans; and 7 of 9 Puerto Rican control subjects, 2 of whom had diarrhea. Aspirates from the patients with sprue had a significantly higher mean colony count and consisted predominantly of coliform organisms (Klebsiella pneumoniae in seven, Enterobacter cloacae in two, and Escherichia coli in one). Both symptomatic Puerto Rican control subjects also harbored coliforms. Representative strains of the predominant conforms isolated from each patient with sprue all produced an enterotoxin that evoked fluid secretion in the rabbit ileal-loop model, and their principal product of fermentation, ethanol, was present in aspirates from eight of nine patients tested. In contrast, the jejunal flora of the asymptomatic Puerto Ricans and North Americans consisted either of Gram-positive or obligatedly anaerobic bacteria, and none of these subjects had ethanol in their aspirate.