EN
Campylobacter spp, gramnegative microorganisms, are currently recognized as a major cause of human acute bacterial enteritis. This bacterium frequently promotes a commensal lifestyle in the gastrointestinal tracts of many animals including birds. The main route of human infections is through improperly handled or undercooked poultry meat. This review article intends to present up-to-date research regarding knowledge of how the bacterium establishes commensalism. To date only a few genes that apparently contribute to avian-gut colonization have been identified by standard genetic techniques such as isogenic mutant construction by gene replacement methodology. The post-genomic era has resulted in new instruments for analyzing virulence and commensalism-related mechanisms. The review outlines some currently conducted Campylobacter transcriptome and proteome analyses aimed at the explanation of the adaptation of the bacterium to different environments. The last part of the review concentrates on mechanisms which regulate the chicken gut colonization process, mainly the new, recently described, two-component signal transduction systems.