Human Intestinal Spirochetosis Incompatible With Dysplastic Adenomatous Epithelium

Abstract

Human intestinal spirochetosis (HIS) refers to the colonization of spirochetal bacteria in the human intestinal tract. HIS caused by Brachyspira spp. has been recognized for decades, but their pathological and clinical significance is largely unclear. The coincidence of dysplasia in adenoma or adenocarcinoma and HIS is very rare, and whether spirochetes can colonize on dysplastic epithelium remains controversial. Here, we report a case that showed abrupt abolition of mucosal surface fringe formation on a tubular adenoma (TA) and increased cytoplasmic MUC1 expression in the dysplastic epithelial cells compared with adjacent nondysplastic colonocytes. The findings support the hypothesis that the epithelial colonization of spirochetes is significantly reduced by dysplasia likely due to loss of microvilli, and an increase of epithelial MUC1 expression might contribute to reduced spirochetal colonization in colonic mucosa.

Identification of Terminal βGlcNAc on Brachyspira Species in Human Intestinal Spirochetosis

“…Some reports indicate that the degree of HIS attachment does not change in TA lesion sites, [11][12][13] whereas some reports indicate a decrease in the amount of HIS attachment in TAs. [14][15][16] Electron microscopic analysis suggests that HIS becomes entrapped between the microvilli of the colonic surface epithelium, and the shortened and obscured microvilli in TAs are thought to inhibit HIS attachment. 14,15 Higher rates of HIS infection have been reported in Japanese patients with SSL.…”