title: Morphological analysis of the sheathed flagellum of Brucella melitensis.
abstract: BACKGROUND
  It was recently shown that B. melitensis is flagellated. However, the flagellar structure remains poorly described.
  
  
  RESULTS
  We analyzed the structure of the polar sheathed flagellum of B. melitensis by TEM analysis and demonstrated that the Ryu staining is a good method to quickly visualize the flagellum by optical microscopy. The TEM analysis demonstrated that an extension of the outer membrane surrounds a filament ending by a club-like structure. The ΔftcR, ΔfliF, ΔflgE and ΔfliC flagellar mutants still produce an empty sheath.
  
  
  CONCLUSIONS
  Our results demonstrate that the flagellum of B. melitensis has the characteristics of the sheathed flagella. Our results also suggest that the flagellar sheath production is not directly linked to the flagellar structure assembly and is not regulated by the FtcR master regulator.
authors.affiliation: Unité de Recherche en Biologie Moléculaire (URBM), Facultés Universitaires Notre-Dame de la Paix (FUNDP), 61 rue de Bruxelles, B-5000 Namur, Belgium. jean-jacques.letesson@fundp.ac.be.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Ferooz
authors.forename: Jean-Jacques
authors.initials: JJ
authors.lastname: Letesson