The novel group of E. coli contains genes similar to those described in uropathogenic and avian pathogenic E. coli and enteropathogenic bacteria such as salmonella, cholera, bubonic plague.
As part of the study Kenneth Simpson and colleagues examined possible causes for the disease in patients with Crohn's restricted to the ileum and the colon versus healthy individuals.
Crohn's disease is a chronic, episodic, inflammatory condition of the gastrointestinal tract characterized by inflammation affecting the entire wall of the involved bowel and skip lesions (areas of inflammation with areas of normal lining in between).
It is a type of inflammatory bowel disease (IBD) and can affect any part of the gastrointestinal tract from mouth to anus; as a result, the symptoms of Crohn's disease vary between affected individuals.
"Given that only about 20 percent of fecal bacteria can be cultured, our group adopted a broad culture-independent approach to target specific subgroups of bacteria for quantitative in situ analysis and culture based characterization," Simpson said.
The study found an increased level of E. coli bacteria in more inflamed areas of the small intestines instead of MAP, a bacterium related to tubercle bacillus that has been more commonly associated with Crohn's.
"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. They suggest that an integrated approach that considers an individual's mucosa-associated flora in addition to disease phenotype and genotype may improve outcome," Simpson added.
The findings of the study were published in The ISME Journal: Multidisciplinary Journal of Microbial Ecology.