Scientific Abstract

Proposal No. IBD-0178
Principal Investigator:  Georgina L. Hold, Ph.D.
Applicant Organization:  University of Aberdeen (United Kingdom)
Project Title:  Assessment of non-pylori Helicobacter species in ulcerative colitis
Period of Award:  July 1, 2006 – October 31, 2010

We hypothesize that non-pylori Helicobacter species may play a role in the etiology of UC.

In order to test our hypothesis, we developed a fluorescent in-situ hybridization (FISH) assay that was capable of differentiating H. pylori from ‘other’ Helicobacter species. We designed a Helicobacter genus-specific 16S rDNA FISH probe and used it in conjunction with a previously published H. pylori species-specific probe. By using the two different probes we were able to detect and discard the presence of H. pylori and identify non-pylori Helicobacter in archival paraffin colonic tissue sections. We assessed the presence of non-pylori Helicobacter in 100 UC patients and 40 healthy controls. Healthy controls were asymptomatic subjects who underwent colonoscopy on account of bleeding, but who were found to have macroscopically and microscopically normal colons. A total of 552 specimen blocks from the 100 UC patients and 120 specimen blocks from healthy controls were examined in triplicate. The presence of non-pylori Helicobacter was detected in 31% of UC subjects in comparison to 22.5% of healthy controls.

Our preliminary results indicate that non-pylori Helicobacter species are commonly detected in UC patients, particularly in those with left-sided colitis. It is therefore important to further characterize the Helicobacter species present in UC patients and to determine their mode of interaction with the host. In order to do this it is imperative that a serious attempt is now made to culture non-pylori Helicobacter from patients with UC. It would therefore appear to be timely to instigate this research project focusing on enumeration of non-pylori Helicobacter from clinical UC samples. If isolation and culture of Helicobacter strains from these subjects is successful, numerous other studies could be instigated that would use these strains to I) generate infection studies, II) study host/microbial interactions, etc.

Our goals are: 1) to collect tissue biopsies from a group of subjects with active UC; 2) to confirm the presence of Helicobacter in tissue biopsies using well-defined molecular methods for the detection of Helicobacter; and 3) to attempt to culture Helicobacter from biopsies that are shown using the molecular methods to be Helicobacter positive.

It is hoped that our results will aid in the development of larger studies that could have an impact on the understanding of IBD and its future therapeutic management.