Bacterial motility is a critical virulence factor of many pathogenic species [5, 6]. Likewise, motility in pathogenic leptospires is a
key determinant of infectivity and host dissemination [7, 8]. The
swimming motility is believed to be reliable strategy to invade host
animals through lesions on the skin or membrane mucosa and
reaches specific organs. Also, after attaching to surfaces of host
cells, leptospires could use crawling to penetrate between cells of
the tissues. To understand the mechanism of motility of Leptospira,
many mutants lacking flagella or deficient in motility have been
investigated [7–12]. “Motile fraction” and “swimming velocity”
are measured primarily in motility assays of such mutants, though,
in some cases, the cell-body rotation rate would be another kinematic parameter for more accurate characterization of the leptospiral motility.
1.2 Motility
Parameters
To clarify significance of the measurement of the cell-body rotation,
representative parameters related to the Leptospira motility are
overviewed below.
Fig. 1 Schematic diagram of the structure of Leptospira. (a) A longitudinal
section. The area surrounded by a dashed square is the enlarged in (b),
explaining the arrangement of membranes. (c) A cross section at the position
indicated by a dashed line in a. (d) A basal motor and a filament of the
periplasmic flagellum
140
Shuichi Nakamura
key determinant of infectivity and host dissemination [7, 8]. The
swimming motility is believed to be reliable strategy to invade host
animals through lesions on the skin or membrane mucosa and
reaches specific organs. Also, after attaching to surfaces of host
cells, leptospires could use crawling to penetrate between cells of
the tissues. To understand the mechanism of motility of Leptospira,
many mutants lacking flagella or deficient in motility have been
investigated [7–12]. “Motile fraction” and “swimming velocity”
are measured primarily in motility assays of such mutants, though,
in some cases, the cell-body rotation rate would be another kinematic parameter for more accurate characterization of the leptospiral motility.
1.2 Motility
Parameters
To clarify significance of the measurement of the cell-body rotation,
representative parameters related to the Leptospira motility are
overviewed below.
Fig. 1 Schematic diagram of the structure of Leptospira. (a) A longitudinal
section. The area surrounded by a dashed square is the enlarged in (b),
explaining the arrangement of membranes. (c) A cross section at the position
indicated by a dashed line in a. (d) A basal motor and a filament of the
periplasmic flagellum
140
Shuichi Nakamura