Abstract
Tapping mode atomic force microscopy (AFM) in solution was used to analyze the role of the internally located periplasmic flagella (PFs) of the Lyme disease spirochete Borrelia burgdorferi in withstanding externally applied cellular stresses. By systematically imaging immobilized spirochetes with increasing tapping forces, we found that mutants that lack PFs are more readily compressed and damaged by the imaging process compared to wild-type cells. This finding suggest that the PFs, aside from being essential for motility and involved in cell shape, play a cytoskeletal role in dissipating energy and maintaining cellular integrity in the presence of external stress.
Highlights
Spirochetes comprise a unique phylum of motile bacteria distinguished by cell morphology, as their cell bodies have either a helical or flat-wave morphology depending on the species
To determine the potential role of the PFs on the ability of spirochetes to withstand external stresses, the application of consistent, well-defined external forces was necessary, which can be achieved by careful application of tapping mode atomic force microscopy (AFM) in solution
Due to experimental limitations imposed by the Scanning probe acceleration microscopy (SPAM) technique used to determine tip/sample forces, images were captured of 10 × 2.5 μm regions of the surface that contained portions of several spirochetes rather than entire cells
Summary
Spirochetes comprise a unique phylum of motile bacteria distinguished by cell morphology, as their cell bodies have either a helical or flat-wave morphology depending on the species. Spirochetes consist of a cell cylinder and periplasmic flagella (PFs) that are contained within an outer membrane (Fig 1) [1,2,3,4,5]. The PFs are structurally similar to the flagella of other bacteria [6], as each consists of a basal body-motor complex, hook, and filament (see recent reviews on spirochete structure and motility [1,3,4,7,8,9]). Being located in the periplasmic space between the protoplasmic cell cylinder and outer membrane, the flagella of spirochetes are isolated from the surrounding environment. The hook structure of the spirochete hooks are unique, as the proteins that comprise the hook form high molecular weight complexes that are stabilized by covalent cross-linking [7,11,12,13]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
