Distribution and characterization of the Escherichia coli heat-stable enterotoxin (STa) receptor throughout the intestinal tract of newborn camels (Camelus dromedaries).

Heat-stable enterotoxin (STa) secretion from Enterotoxigenic Escherichia coli (ETEC) is crucial for the pathogenesis of diarrhea in both animal and human. The goal of this study was to investigate the distribution of the STa-specific receptors in the newborn camel's enterocytes and brush border membrane vesicles (BBMVs). Flow cytometric analysis was used to investigate the density of STa-receptors on enterocytes and BBMVs prepared from anterior jejunum, posterior jejunum, ileum, and colon. Strong density and affinity of STa-receptors was present on enterocytes and BBMVs of the ileum compared to that in the other intestinal segments. It was concluded that the ileum is the major target for STa action in newborn camels.