Electron-Microscopic Evidence on the Structure of Spirochætes

Bradfield, J. R. G.; Cater, D. B.

doi:10.1038/169944a0

Cited by 55 publications

(13 citation statements)

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“…Contraction of these filaments caused the cells to be helically shaped (42). Although they were partially correct in that B. burgdorferi does indeed have a rod-shaped cell cylinder, their overall proposal was incorrect: a given periplasmic flagellum is attached to only one end (2,5,7,43), and it rotates instead of contracts (4).…”

Section: Discussionmentioning

confidence: 99%

Borrelia burgdorferi periplasmic flagella have both skeletal and motility functions

Motaleb

Corum

Bono

et al. 2000

Proc. Natl. Acad. Sci. U.S.A.

202

304

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Bacterial shape usually is dictated by the peptidoglycan layer of the cell wall. In this paper, we show that the morphology of the Lyme disease spirochete Borrelia burgdorferi is the result of a complex interaction between the cell cylinder and the internal periplasmic flagella. B. burgdorferi has a bundle of 7-11 helically shaped periplasmic flagella attached at each end of the cell cylinder and has a flat-wave cell morphology. Backward moving, propagating waves enable these bacteria to swim in both low viscosity media and highly viscous gel-like media. Using targeted mutagenesis, we inactivated the gene encoding the major periplasmic flagellar filament protein FlaB. The resulting flaB mutants not only were nonmotile, but were rod-shaped. Western blot analysis indicated that FlaB was no longer synthesized, and electron microscopy revealed that the mutants were completely deficient in periplasmic flagella. Wild-type cells poisoned with the protonophore carbonyl cyanide-m-chlorophenylhydrazone retained their flat-wave morphology, indicating that the periplasmic flagella do not need to be energized for the cell to maintain this shape. Our results indicate that the periplasmic flagella of B. burgdorferi have a skeletal function. These organelles dynamically interact with the rodshaped cell cylinder to enable the cell to swim, and to confer in part its flat-wave morphology.spirochete ͉ Lyme disease ͉ allelic exchange ͉ morphology S pirochetes have a unique position among the bacteria. These motile bacteria are one of the few bacterial phyla that can be identified by both 16S ribosomal RNA sequence analysis and morphology (1). Outermost is a membrane sheath, and within this sheath are the cell cylinder and periplasmic flagella. A given periplasmic flagellum is attached subterminally at only one end of the cell cylinder, and it resides within the periplasmic space (2). Depending on the species, the cell morphology is either a helix, a flat wave, or an irregularly shaped helix (2-4). The size of the spirochete, the number of periplasmic flagella attached at each end, and whether the filaments overlap at the center of the cell varies from species to species (2, 5). This phylum contains many medically important bacteria including Treponema pallidum (syphilis), several Borrelia species (relapsing fever), Borrelia burgdorferi (Lyme disease), Leptospira interrogans (leptospirosis), Brachyspira sp. (human diarrheal disease, swine dysentery), and oral treponemes associated with periodontal disease (5-8).The periplasmic flagella of spirochetes have been characterized in detail. Genetic evidence, including targeted mutagenesis studies in Treponema denticola and Brachyspira hyodysenteriae, have shown that these organelles are directly involved in motility (9, 10) (C. Li and N.W.C., unpublished observations). By analyzing protruding periplasmic flagella from certain motility mutants of T. phagedenis, and from stationary-phase cells of several spirochete species, these organelles have been shown to rotate in a manner similar to th...

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Section: Discussionmentioning

confidence: 99%

Borrelia burgdorferi periplasmic flagella have both skeletal and motility functions

Motaleb

Corum

Bono

et al. 2000

Proc. Natl. Acad. Sci. U.S.A.

202

304

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“…The length of the treponemes measured along the axis of their helices is about 10-13 p in average (Figs. 1 ,2 ,3a,3b). The shortest and longest observed is 6 and 20 p , respectively.…”

Section: Observations On Negatively Stained Organisinsmentioning

confidence: 99%

ELECTRON MICROSCOPY OF TREPONEMA PALLIDUM NICHOLS

Jepsen

Hougen

Bikch-Andersen

1968

Acta Pathologica Microbiologica Scandinavica

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“…Bradfield & Cater, 1952 ;Swain, 1955) Leptospira and spirochaetes of the relapsing fever and Treponema pallidum groups lack flagella of the ordinary kind, though the fibrils which are seen when the organisms are broken up bear some resemblance to flagella and perhaps constitute intracellular locomotor apparatus. It was therefore of interest to see whether treatment which sufficed to deflagellate salmonella and other flagellated bacteria would affect the characteristic movements of such non-flagellated organisms.…”

Section: Efect Of Blendor Treatment On Motile Bacteria Of Non-jlagellmentioning

confidence: 99%

The Effect of Non-Lethal Deflagellation on Bacterial Motility and Observations on Flagellar Regeneration

Stocker

Campbell

1959

Journal of General Microbiology

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The flagellation and motility of Salmonella typhimurium were unaffected by proteolytic enzymes ; but when washed stationary-phase bacteria were briefly exposed to acid (e.g. pH 2.6 for 30 sec. at 43") the proportion of motile, and of flagellated, bacteria was decreased from more than 50 yo to less than 1 yo, with little or no decrease in viable count. When S. typhimurium or Vibrio metchnikowi grown on stiff agar were rubbed for several minutes on the agar, the proportion of motile and of flagellated bacteria was decreased from c. 90 yo (found in control bacteria, soaked off without rubbing) to c. 1 %, without decrease in viable count. High-speed stirring in a blendor also deflagellated and destroyed the motility of S. typhimurium in suspension, without killing the bacteria or retarding their growth. Blendor treatment sufficient to deflagellate s. typhimurium had no effect on the movements of certain non-flagellated motile organisms (Leptospira canicola, Treponema pallidum and T . duttoni), except when it caused gross morphological changes, attributed to cell damage. When log-phase broth cultures of S. typhimurium deflagellated in the blendor were incubated, bacteria with flagella (at first all short) and motile bacteria soon reappeared. At first many bacteria rotated; this suggests that flagella shorter than c. 0 . 3 ,~ cause rotational, but not translational, motility. The rate of increase of mean summed flagellar length/bacterium was compatible with the hypothesis that flagella are not (spontaneously) shed in broth cultures of S. typhimurium and that the rate of growth of flagella is unaffected by deflagellation. Up to one generation time after deflagellation the mean number of flagella/bacterium was, however, less than before deflagellation. It is inferred that in a log-phase culture about half the flagella present at any one moment are 'fully-grown', incapable of being regenerated when broken off. All the results obtained are compatible with the hypothesis that the motility of flagellated bacteria is due to active movement of their flagella.During work on the genetics of motility and flagellation in salmonella a nonlethal method of removing flagella from bacteria was needed. No satisfactory way of stripping selected individual bacteria of their flagella has been found, but it appeared that whole cultures might be deflagellated, without killing the bacteria, by several different methods. Such methods should provide a test of the hypothesis that the motility of flagellated bacteria results only from the active movement of their flagella, for total removal of the flagella would then necessarily result in loss of motility; whereas if normal motility in salmonella, etc., results from alterations of the shape of the bacterial body (Pijper, 1948(Pijper, , 1957, a treatment which removed all flagella might still leave motility unaffected. The effect of the application of similar treatment to motile bacteria which do not possess flagella (Leptospira, etc.) was also investigated, as a partial 'control' on the effects...

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Electron-Microscopic Evidence on the Structure of Spirochætes

Cited by 55 publications

References 1 publication

Borrelia burgdorferi periplasmic flagella have both skeletal and motility functions

Borrelia burgdorferi periplasmic flagella have both skeletal and motility functions

ELECTRON MICROSCOPY OF TREPONEMA PALLIDUM NICHOLS

The Effect of Non-Lethal Deflagellation on Bacterial Motility and Observations on Flagellar Regeneration

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