Scientific Abstract

Proposal No. IBD-0273R
Principal Investigator:  Li Zhang, MBBS, Ph.D.
Applicant Organization:  The University of New South Wales (Sydney, Australia)
Project Title:  Investigation of the possible role of non-jejuni Campylobacter species in inflammatory bowel disease in adult population
Period of Award:  August 1, 2009 - January 31, 2011

Strong evidence from both animal and human studies indicates that a bacterial component is involved in the pathogenesis of inflammatory bowel disease (IBD). Recently, we detected a significantly higher prevalence of non-jejuni Campylobacter species in children with CD as compared with controls. Among the non-jejuni Campylobacter species detected, Campylobacter concisus was of particular interest as this organism was detected in the intestinal biopsies of 51% children with CD as compared with only 2% of controls.Using a whole cell lysate prepared from a C. concisus isolate cultured from a patient with CD as antigens, we have detectedsignificantly higher levels of antibodies to C. concisus in children with CD as compared to controls using ELISA.

To further investigate the clinical significance of non-jejuni Campylobacter species in human IBD, it is important to examine the prevalence of these bacterial species in an adult population, as well as to examine the immune responses towards non-jejuni Campylobacter species in patients with IBD controls. The specific aims of this project are:

1.      To determine the prevalence of non-jejuni Campylobacter species in adult patients with newly diagnosed IBD, relapsing IBD and controls 
2.      To detect the immune responses specific to C. concisus in the above patients and controls and to determine the immune reactive proteins 
3.      To investigate whether anti-inflammatory and antibiotic therapies currently used in the treatment of IBD can eradicate non-jejuni Campylobacter species
4.      To investigate the susceptibility of isolated non-jejuni Campylobacter species to a range of antibiotics

The proposed project will provide novel information regarding the potential bacterial etiology of human IBD. Furthermore, if the association between non-jejuni Campylobacter species and IBD, which we have discovered in pediatric population, is also found in adult population, an effective antibiotic therapy can be developed and used for the treatment of IBD.