title: Motility is crucial for the infectious life cycle of Borrelia burgdorferi.
abstract: The Lyme disease spirochete, Borrelia burgdorferi, exists in a zoonotic cycle involving an arthropod tick and mammalian host. Dissemination of the organism within and between these hosts depends upon the spirochete's ability to traverse through complex tissues. Additionally, the spirochete outruns the host immune cells while migrating through the dermis, suggesting the importance of B. burgdorferi motility in evading host clearance. B. burgdorferi's periplasmic flagellar filaments are composed primarily of a major protein, FlaB, and minor protein, FlaA. By constructing a flaB mutant that is nonmotile, we investigated for the first time the absolute requirement for motility in the mouse-tick life cycle of B. burgdorferi. We found that whereas wild-type cells are motile and have a flat-wave morphology, mutant cells were nonmotile and rod shaped. These mutants were unable to establish infection in C3H/HeN mice via either needle injection or tick bite. In addition, these mutants had decreased viability in fed ticks. Our studies provide substantial evidence that the periplasmic flagella, and consequently motility, are critical not only for optimal survival in ticks but also for infection of the mammalian host by the arthropod tick vector.
authors.affiliation: Department of Microbiology and Immunology, Brody School of Medicine, East Carolina University, Greenville, North Carolina, USA.
authors.forename: Syed Z
authors.initials: SZ
authors.lastname: Sultan
authors.forename: Akarsh
authors.initials: A
authors.lastname: Manne
authors.forename: Philip E
authors.initials: PE
authors.lastname: Stewart
authors.forename: Aaron
authors.initials: A
authors.lastname: Bestor
authors.forename: Patricia A
authors.initials: PA
authors.lastname: Rosa
authors.forename: Nyles W
authors.initials: NW
authors.lastname: Charon
authors.forename: M A
authors.initials: MA
authors.lastname: Motaleb
mesh_terms: D000818:Animals; D001096:Arachnid Vectors / Q000382:microbiology*; D025065:Borrelia burgdorferi / Q000166:cytology / Q000235:genetics / Q000502:physiology*; D005408:Flagellin / Q000235:genetics / Q000378:metabolism; D018884:Ixodes / Q000382:microbiology*; D008193:Lyme Disease / Q000382:microbiology* / Q000635:transmission; D051379:Mice; D008809:Mice, Inbred C3H; D009068:Movement / Q000502:physiology*; D009154:Mutation; D009758:Nymph / Q000382:microbiology
chemical_list: D005408:Flagellin; C416532:flaB flagellin