Reversible expression of flagella in Campylobacter jejuni

Campylobacter jejuni 81116 and A3249 undergo a bidirectional transition between flagellated (Fla+) and aflagellated (Fla-) phenotypes. When measured in culture medium, the Fla+----Fla- transition occurred at a rate of 3.1 X 10(-3) to 5.9 X 10(-3) per cell per generation, and the Fla- to Fla+ transition occurred at a rate of 4.0 X 10(-7) to 8.0 X 10(-7) per cell per generation. However, passage through a rabbit intestine markedly favored the Fla+ phenotype.