Scientific Abstract

Proposal No.  IBD-0032
Principal Investigator: Timothy Florin, MBBS
Applicant Organization: The University of Queensland (Brisbane, Australia)
Project Title: Mucosal bacterial pathogens in inflammatory bowel disease
Period of Award:  December 1, 2002 – February 28, 2005

The primary cause(s) of inflammatory bowel disease (IBD) remain unknown.  There is general agreement that bacterial products could drive the inflammation in IBD with an aberrant mucosal immune response to those bacterial products.  While any bacteria that colonize the mucosa may drive an inflammatory response in a predisposed host, we believe that the type of bacteria is important for IBD pathogenesis.  Past research has relied heavily on traditional culture-based methods mainly of feces, has failed to convincingly demonstrate specific IBD pathogens.  Our research is focused on mucosal-associated bacteria because these are the bacteria that interact with the mucosal immune system.

Our principal hypothesis is that there are specific mucosal bacteria associated with Crohn’s disease (CD) and ulcerative colitis (UC) (CDAB, UCAB).  We have already developed an accurate picture of the microbial ecology of mucosal bacteria in healthy humans by using the latest and appropriate molecular microbial ecology and microbiology methods.  We will identify qualitative and quantitative differences in CD and UC, which will lead on to the design of specific 16S targeted DNA probe/PCR primers for CDAB and UCAB sequences.  Our team includes expertise in clinical IBD, microbiology, and molecular microbial ecology.   Isolates or enrichment cultures should enable us to elucidate the biology of these mucosal bacteria with respect to mucolytic activity and effect on antigen presenting cells vs. IBD phenotype and genotype.  Isolation/enrichment of these bacteria could lead to the characterization of specific antibodies in serum, the development of diagnostic blood tests for IBD pathogens and antibiotic treatments for IBD, analogous to the testing for and treatment of Helicobacter pylori.  Our research could revolutionize the understanding and treatment of IBD.