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.
Highlights
Human intestinal spirochetosis (HIS) refers to the colonization of spirochetal bacteria in the human intestinal tract, Brachyspira species in the colorectum [1-3]
Since the introduction of the name Brachyspira aalborgi by Hovind-Hougen et al in 1982 [2], two main lineages of Brachyspira species, B. aalborgi and B. pilosicoli, have so far been identified by phylogenetic analysis of bacterial 16S rRNA gene, among which B. aalborgi accounts for the majority of cases in humans [2,3]
Other studies reported coincident diagnosis of HIS and adenomatous polyps or carcinomas without specifying whether the spirochetes were present on the surface of dysplastic epithelia or were only seen on the surface of nondysplastic colonocytes surrounding the adenomas or adenocarcinomas [3,10]
Summary
Human intestinal spirochetosis (HIS) refers to the colonization of spirochetal bacteria in the human intestinal tract, Brachyspira species in the colorectum [1-3]. Several other studies contrasted this finding by showing that spirochetes were present on the dysplastic epithelia of tubular and villous adenomas (VA) [7-9]. Other studies reported coincident diagnosis of HIS and adenomatous polyps or carcinomas without specifying whether the spirochetes were present on the surface of dysplastic epithelia or were only seen on the surface of nondysplastic colonocytes surrounding the adenomas or adenocarcinomas [3,10]. These conflicting observations imply a more complex interaction between epithelial cells and spirochetes. TA: tubular adenoma; HIS: human intestinal spirochetosis; IHC: immunohistochemical stain
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
