Implications of back-and-forth motion and powerful propulsion for spirochetal invasion

Abstract

The spirochete Leptospira spp. can move in liquid and on a solid surface with two periplasmic flagella (PFs), and the motility is essential virulence factor for the pathogenic species. Although the fact that mammals are infected with the spirochete through wounded dermis imply the importance of behaviors on the boundary with such viscoelastic milieu, how the leptospiral pathogenicity involves motility remains unclear. We used the glass chamber containing a gel area adjoining the leptospiral suspension to resemble host dermis exposed to contaminated water and analyzed the motility of individual cells at the liquid-gel border. Insertion of one end of the cell body to the gel increased switching of the swimming direction. We also measured the swimming force of Leptospira by trapping single cells using optical tweezer, showing that they can produce ~17 pN, which is ~30 times of the swimming force of Escherichia coli. The force-speed relationship suggested the load-dependent force enhancement and showed that the power (the work per unit time) for the propulsion is ~3.1×10 -16 W, which is two-order larger than the propulsive power of E. coli. Powerful, efficient propulsion of Leptospira with back-andforth movements enabling them to explore invasion routes could facilitate percutaneous infection.

Dynamics of Borrelia Burgdorferi Invasion and Intravasation in a Tissue Engineered Dermal Microvessel Model

“…These results are consistent with the hypothesis that Bb and other spirochetes (e.g. Leptospira) use back-and-forth motion as a trial and error method to circumvent obstacles in tissues (32,50). We found no directional bias in the migration of Bb (Fig.…”

Disassembly of the apical junctional complex during the transmigration of Leptospira interrogans across polarized renal proximal tubule epithelial cells

“…However, we could not rule out the role of other Rho regulatory proteins such as p120‐catenin which is altered in L. interrogans ‐ infected RPTECs (Schackmann, Tenhagen, van de Ven, & Derksen, 2013) (Figure 8). Moreover, the tight interactions of L. interrogans with the plasma membrane and efficient propulsion of L. interrogans using back ‐and forth movements can facilitate their invasion through AJCs and apply an additional mechanical force to enhance AJC disassembly (Abe, Kuribayashi, Takabe, & Nakamura, 2020).…”

3D cryo-EM imaging of bacterial flagella: Novel structural and mechanistic insights into cell motility

“…Although such endoflagella are very similar to typical exoflagella regarding their architecture and protein composition, the fact that they evolved as an entirely periplasmic machine is driving an ongoing shift of the accepted bacterial motility paradigm. Even though further research is needed to fully elucidate the endoflagellar motility mechanism, it seems clear that their role involves a form of "dragging" the bacterial cell body and influencing cell morphology (24,25). Accordingly, Spirochetes possess flagellar motors that can exert the highest 41)).…”