Vibrio cholerae Flagellar Synthesis and Virulence

Vibrio cholerae is a Gram-negative bacterium with a single sheathed polar flagellum (Fig. 1.). V. cholerae causes the severe diarrheal disease cholera in humans when it colonizes the small intestine and expresses various virulence factors, including cholera toxin (CT) and toxin coregulated pilus (TCP). V. cholerae is also a natural inhabitant of the marine environment, where it forms biofilms on chitinous surfaces. Motility contributes to both aspects of the V. cholerae lifecycle. The flagellum facilitates chemotactic-directed movement toward the preferred colonization site within the intestine (Camilli and Mekalanos 1995; Butler and Camilli 2004), and also contributes to biofilm formation within the environment (Watnick and Kolter 1999). V. cholerae strains defective for motility are less virulent than motile strains (Guentzel and Berry 1975; Freter and O'Brien 1981; Richardson 1991). As flagellar synthesis, motility, and chemotaxis have become better understood in V. cholerae, it has also become clear that motility is intimately integrated into all aspects of the lifestyle of this bacterium.