DNA rearrangements in the flagellin locus of an flaA mutant of Campylobacter jejuni during colonization of chicken ceca

Campylobacter jejuni is an enteropathogen for humans but commensal for chic kens. In both hosts, the flagella and motility are important colonization f actors. The flagellin gene is duplicated in Campylobacter, but only one fla gellin gene, flaA, is sufficient for motility. We found that, during coloni zation of the chicken intestine, a nonmotile flaA mutant of C. jejuni under went rearrangements within its flagellin locus, thereby regaining its motil ity and colonization capacity. In contrast, in vitro motile revertants isol ated from liquid culture showed different flagellin DNA rearrangements than after reversion in the chicken.