[ODP-050] Direct measurement of filamentous-shaped motility of clinically isolated Vibrio cholerae O1
Background: Vibrio cholerae serogroup O1 is known to transform from a comma-like shape to elongated filamentous cells under starvation and chemical stress conditions. Recently, we have found that V. cholerae O1 exhibits unique motility in its filamentous shape. This study aims to elucidate the unique movement pattern of V. cholerae O1.
Materials and methods: Two clinically isolated strains, V. cholerae O1 El Tor N16961 and V. cholerae O1 classical 569B were used. V. cholerae suspension was applied into a flow chamber, and cell movement was recorded. Individual swimming speeds and rotation rates of the bacterial cell were measured with oblique dark-field microscopy and analyzed using ImageJ, VBA-Macro, LabVIEW.
Results: To observe the motility of filamentous cells, we have established a method for inducing V. cholerae from a comma-like shape to a filamentous shape without the loss of motility. The filamentous cells elongated ten times as long as the comma-like cells. Furthermore, filamentous V. cholerae O1 showed a unique movement pattern different from that of comma-like cells. That is, it produced a strong torque (calculation) while moving at a relatively low speed (measured value) and was barely affected by the viscosity of the surrounding liquid. This study is thought to elucidate a novel movement mode and its mechanism, different from the well-known V. cholerae.