A team of Cornell scientists has discovered that intestinal inflammation in patients with Crohn's disease may be associated with a novel group of E. coli bacteria with genes similar to bacteria that cause diseases ranging from salmonella to cholera and even bubonic plague.

The team -- which includes scientists from Cornell's College of Veterinary Medicine, College of Agriculture and Life Sciences, and Weill Cornell Medical College -- published the findings in the July 12 issue of The ISME (International Society for Microbial Ecology) Journal: Multidisciplinary Journal of Microbial Ecology.

Mycobacterium avium paratuberculosis (MAP) bacteria have long been suspected to play a pivotal role in the development of Crohn's disease -- an incurable disorder that most commonly causes inflammation in the ileum, the lower part of the small intestine -- but the mechanisms that drive the inflammatory response have remained elusive.

The researchers compared the intestines of healthy individuals with the intestines of patients with Crohn's restricted to the ileum and the colon. They found an increased level of E. coli in more inflamed areas of the small intestines instead of MAP bacteria.

"Our findings raise the possibility that a novel group of E. coli contains opportunistic pathogens that may be causally related to chronic intestinal inflammation in susceptible individuals," said Kenneth Simpson, professor of small animal medicine at the College of Veterinary Medicine and the paper's senior author. "They suggest that an integrated approach that considers an individual's mucosa-associated flora in addition to disease phenotype and genotype may improve outcome," he said.

Crohn's disease affects 1 in 1,000 people in Europe and North America.

The study was supported by Cornell's intercampus collaboration seed grant program.