Dr Thomas Kirn and colleagues investigated a hypothesis, to identify a single protein required for efficient intestinal colonization.
Many bacteria that cause diseases must be able to survive inside and outside the host.
Attachment to and colonization of abiotic or biotic surfaces is a common mechanism by which various microorganisms enhance their ability to survive in diverse environments.
Vibrio cholerae is a Gram-negative aquatic bacillus that is often found in the environment attached to the chitinous exoskeletons of zooplankton.
The researchers note previous suggestions that attachment to zooplankton enhances environmental survival of Vibrio spp.
| Some serogroups of V cholerae cause the diarrhoeal disease cholera|
The survival is enhanced probably by the attachment providing both a source of carbon and nitrogen and protection from numerous environmental challenges.
The research team report that, on ingestion by humans, some serogroups of V cholerae cause the diarrhoeal disease cholera.
The pathophysiology of cholera is a result of the effects of cholera toxin on intestinal epithelial cells.
For sufficient quantities of cholera toxin to reach the intestinal epithelium and to produce clinical symptoms, colonization of the small bowel must occur.
Most V cholerae do not colonize humans, but all probably require strategies for survival in the environment.
The team considered that colonization factors selected for in the environment may be the same as those required for intestinal colonization of humans.
Dr Kirn's team concludes, “In support of this hypothesis, here we have identified a single protein required for efficient intestinal colonization that mediates attachment to both zooplankton and human epithelial cells by binding to a sugar present on both surfaces.”