AimsTo elucidate an entry site of staphylococcal enterotoxin A (SEA), which is a major toxin for staphylococcal foodborne poisoning, into gastrointestinal tissue using a house musk shrew model. Methods and ResultsHouse musk shrews were per orally administered with recombinant SEA and localization of SEA in gastrointestinal tissues was investigated by immunohistochemistry and immunoelectron microscopy 30min after administration. SEA was detected in a subset of intestinal epithelial cells and lamina propria in the villi of jejunum and ileum. This observation was also found in gastrointestinal loops. Morphological characteristics of the SEA-immunopositive cells indicated that goblet cells are an entry site of SEA.SEA entered mucus-expelling goblet cells and the induction of mucus secretion by alyll isothiocyanate resulted in an intensive SEA signal. These results suggest that mucus secretion by goblet cells is important for the translocation of SEA. ConclusionsSEA can translocate across intestinal epithelia via mucus-expelling goblet cells. Significance and Impacts of the StudyAn entry site of SEA during translocation across the gastrointestinal mucosal barrier was investigated. This study was the first to demonstrate the significance of goblet cells as an entry site of this bacterial toxin.