A novel Campylobacter jejuni two-component regulatory system important for temperature-dependent growth and colonization.

Campylobacter jejuni colonizes the intestines of domestic and wild animals and is a common cause of human diarrheal disease. We identified a two-component regulatory system, designated the RacR-RacS (reduced ability to colonize) system, that is involved in a temperature-dependent signalling pathway. A mutation of the response regulator gene racR reduced the organism's ability to colonize the chicken intestinal tract and resulted in temperature-dependent changes in its protein profile and growth characteristics.