Twitching motility is a form of solid surface translocation which occurs in a wide range of bacteria and which is dependent on the presence of functional type IV fimbriae or pili. A detailed examination of twitching motility in under optimal conditions was carried out. Under these conditions (at the smooth surface formed between semi-solid growth media and plastic or glass surfaces) twitching motility is extremely rapid, leading to an overall radial rate of colony expansion of 06 mm h or greater. The zones of colony expansion due to twitching motility are very thin and are best visualized by staining. These zones exhibit concentric rings in which there is a high density of microcolonies, which may reflect periods of expansion and consolidation/cell division. Video microscopic analysis showed that twitching motility involves the initial formation of large projections or rafts of aggregated cells which move away from the colony edge. Behind the rafts, individual cells move rapidly up and down trails which thin and branch out, ultimately forming a fine lattice-like network of cells. The bacteria in the lattice network then appear to settle and divide to fill out the colonized space. Our observations redefine twitching motility as a rapid, highly organized mechanism of bacterial translocation by which can disperse itself over large areas to colonize new territories. It is also now clear, both morphologically and genetically, that twitching motility and social gliding motility, such as occurs in , are essentially the same process.


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  1. Alm, R. A. & Mattick, J. S. (1995). Identification of a gene, pilV, required for type 4 fimbrial biogenesis in Pseudomonas aeruginosa whose product possesses a prepilin-like leader sequence. Mol Microbiol 16, 485-496.[CrossRef] [Google Scholar]
  2. Alm, R. A. & Mattick, J. S. (1997). Genes involved in the biogenesis and function of type-4 fimbriae in Pseudomonas aeruginosa. Gene 192, 89-98.[CrossRef] [Google Scholar]
  3. Barnett, T. C., Kirov, S. M., Strom, M. S. & Sanderson, K. (1997).Aeromonas spp. possess at least two distinct type IV pilus families. Microb Pathog 23, 241-247.[CrossRef] [Google Scholar]
  4. Berg, H. C. & Turner, L. (1995). Cells of Escherichia coli swim either end forward. Proc Natl Acad Sci USA 92, 477-479.[CrossRef] [Google Scholar]
  5. Bradley, D. E. (1972a). Evidence for the retraction of Pseudomonas aeruginosa RNA phage pili. Biochem Biophys Res Commun 47, 142-149.[CrossRef] [Google Scholar]
  6. Bradley, D. E. (1972b). Shortening of Pseudomonas aeruginosa pili after RNA-phage adsorption. J Gen Microbiol 72, 303-319.[CrossRef] [Google Scholar]
  7. Bradley, D. E. (1974). The adsorption of Pseudomonas aeruginosa pilus-dependent bacteriophages to a host mutant with nonretractile pili. Virology 58, 149-163.[CrossRef] [Google Scholar]
  8. Bradley, D. E. (1980). A function of Pseudomonas aeruginosa PAO pili: twitching motility. Can J Microbiol 26, 146-154.[CrossRef] [Google Scholar]
  9. Chi, E., Mehl, T., Nunn, D. & Lory, S. (1991). Interaction of Pseudomonas aeruginosa with A549 pneumocyte cells. Infect Immun 59, 822-828. [Google Scholar]
  10. Comolli, J. C., Hauser, A. R., Waite, L., Whitchurch, C. B., Mattick, J. S. & Engel, J. N. (1999).Pseudomonas aeruginosa gene products PilT and PilU are required for cytotoxicity in vitro and virulence in a mouse model of acute pneumonia. Infect Immun 67, 3625-3630. [Google Scholar]
  11. Dalrymple, B. & Mattick, J. S. (1987). An analysis of the organization and evolution of type 4 fimbrial (MePhe) subunit proteins. J Mol Evol 25, 261-269.[CrossRef] [Google Scholar]
  12. Darzins, A. (1993). The pilG gene product, required for Pseudomonas aeruginosa pilus production and twitching motility, is homologous to the enteric, single-domain response regulator CheY. J Bacteriol 175, 5934-5944. [Google Scholar]
  13. Darzins, A. (1994). Characterization of a Pseudomonas aeruginosa gene cluster involved in pilus biosynthesis and twitching motility: sequence similarity to the chemotaxis proteins of enterics and the gliding bacterium Myxococcus xanthus. Mol Microbiol 11, 137-153.[CrossRef] [Google Scholar]
  14. Darzins, A. (1995). The Pseudomonas aeruginosapilK gene encodes a chemotactic methyltransferase (CheR) homologue that is translationally regulated. Mol Microbiol 15, 703-717. [Google Scholar]
  15. Dorr, J., Hurek, T. & Reinhold-Hurek, B. (1998). Type IV pili are involved in plant–microbe and fungus–microbe interactions. Mol Microbiol 30, 7-17.[CrossRef] [Google Scholar]
  16. Farinha, M. A., Conway, B. D., Glasier, L. M. G., Ellert, N. W., Irvin, R. T., Sherburne, R. & Paranchych, W. (1994). Alteration of the pilin adhesin of Pseudomonas aeruginosa PAO results in normal pilus biogenesis but a loss of adherence to human pneumocyte cells and decreased virulence in mice. Infect Immun 62, 4118-4123. [Google Scholar]
  17. Forest, K. T. & Tainer, J. A. (1997). Type-4 pilus-structure: outside to inside and top to bottom – a minireview. Gene 192, 165-169.[CrossRef] [Google Scholar]
  18. Govan, J. & Deretic, V. (1996). Microbial pathogenesis in cystic fibrosis: mucoid Pseudomonas aeruginosa and Burkholderia cepacia. Microbiol Rev 60, 539-574. [Google Scholar]
  19. Hazlett, L. D., Moon, M. M., Singh, A., Berk, R. S. & Rudner, X. L. (1991). Analysis of adhesion, piliation, protease production and ocular infectivity of several P. aeruginosa strains. Curr Eye Res 10, 351-362.[CrossRef] [Google Scholar]
  20. Henrichsen, J. (1972). Bacterial surface translocation: a survey and a classification. Bacteriol Rev 36, 478-503. [Google Scholar]
  21. Henrichsen, J. (1975). The occurrence of twitching motility among Gram-negative bacteria. Acta Pathol Microbiol Scand Sect B 83, 171-178. [Google Scholar]
  22. Henrichsen, J. (1983). Twitching motility. Annu Rev Microbiol 37, 81-93.[CrossRef] [Google Scholar]
  23. Henrichsen, J. & Blom, J. (1975). Examination of fimbriation of some gram-negative rods with and without twitching and gliding motility. Acta Pathol Microbiol Scand Sect B 83, 161-170. [Google Scholar]
  24. Hobbs, M. & Mattick, J. S. (1993). Common components in the assembly of type 4 fimbriae, DNA transfer systems, filamentous phage and protein secretion apparatus; a general system for the formation of surface-associated protein complexes. Mol Microbiol 10, 233-243.[CrossRef] [Google Scholar]
  25. Hobbs, M., Collie, E. S. R., Free, P. D., Livingston, S. P. & Mattick, J. S. (1993). PilS and PilR, a two-component transcriptional regulatory system controlling transcription of type 4 fimbriae in Pseudomonas aeruginosa. Mol Microbiol 7, 669-682.[CrossRef] [Google Scholar]
  26. Hodgkin, J. & Kaiser, D. (1979). Genetics of gliding motility in Myxococcus xanthus (Myxobacterials): Two gene systems control movement. Mol Gen Genet 171, 177-191.[CrossRef] [Google Scholar]
  27. Kaiser, D. (1979). Social gliding is correlated with the presence of pili in Myxococcus xanthus. Proc Natl Acad Sci USA 76, 5952-5956.[CrossRef] [Google Scholar]
  28. Lautrop, H. (1961).Bacterium anitratum transferred to the genus Cytophaga. Int Bull Bacteriol Nomencl Taxon 11, 107-108. [Google Scholar]
  29. Liles, M. R., Viswanathan, V. K. & Cianciotto, N. P. (1998). Identification and temperature regulation of Legionella pneumophila genes involved in type IV pilus biogenesis and type II protein secretion. Infect Immun 66, 1776-1782. [Google Scholar]
  30. McBride, M. J., Weinberg, R. A. & Zusman, D. R. (1989). ‘‘Frizzy’’ aggregation genes of the gliding bacterium Myxococcus xanthus show sequence similarities to the chemotaxis genes of enteric bacteria. Proc Natl Acad Sci USA 86, 424-428.[CrossRef] [Google Scholar]
  31. McCleary, W. R. & Zusman, D. R. (1990). FrzE of Myxococcus xanthus is homologous to both CheA and CheY of Salmonella typhimurium. Proc Natl Acad Sci USA 87, 5898-5902.[CrossRef] [Google Scholar]
  32. McMichael, J. C. (1992). Bacterial differentiation within Moraxella bovis colonies growing at the interface of the agar medium with the Petri dish. J Gen Microbiol 138, 2687-2695.[CrossRef] [Google Scholar]
  33. Mattick, J. S. & Alm, R. A. (1995). Common architecture of type 4 fimbriae and complexes involved in macromolecular traffic. Trends Microbiol 3, 411-413.[CrossRef] [Google Scholar]
  34. Mattick, J. S., Bills, M. M., Anderson, B. J., Dalrymple, B., Mott, M. R. & Egerton, J. R. (1987). Morphogenetic expression of Bacteroides nodosus fimbriae in Pseudomonas aeruginosa. J Bacteriol 169, 33-41. [Google Scholar]
  35. Mattick, J. S., Hobbs, M., Cox, P. T. & Dalrymple, B. P. (1993). Molecular biology of the fimbriae of Dichelobacter (prev. Bacteroides) nodosus. In Genetics and Molecular Biology of Anaerobic Bacteria, pp. 517-545. Edited by M. Sebald. New York: Springer.
  36. O’Toole, G. A. & Kolter, R. (1998). Flagellar and twitching motility are necessary for Pseudomonas aeruginosa biofilm development. Mol Microbiol 30, 295-304.[CrossRef] [Google Scholar]
  37. Ottow, J. C. G. (1975). Ecology, physiology and genetics of fimbriae and pili. Annu Rev Microbiol 29, 79-108.[CrossRef] [Google Scholar]
  38. Parge, H. E., Forest, K. T., Hickey, M. J., Christensen, D. A., Getzoff, E. D. & Tainer, J. A. (1995). Structure of the fibre-forming protein pilin at 2·6 Å resolution. Nature 378, 32-38.[CrossRef] [Google Scholar]
  39. Rodriguez-Soto, J. P. & Kaiser, D. (1997). Identification and localization of the Tgl protein, which is required for Myxococcus xanthus social motility. J Bacteriol 179, 4372-4381. [Google Scholar]
  40. Roine, E., Raineri, D. M., Romantschuk, M., Wilson, M. & Nunn, D. N. (1998). Characterization of type IV pilus genes in Pseudomonas syringae pv. tomato DC3000. Mol Plant Microbe Interact 11, 1048-1056.[CrossRef] [Google Scholar]
  41. Rothbard, J. B., Fernandez, R., Wang, L., Teng, N. N. H. & Schoolnik, G. K. (1985). Antibodies to peptides corresponding to a conserved sequence of gonococcal pilins block bacterial adhesion. Proc Natl Acad Sci USA 82, 915-919.[CrossRef] [Google Scholar]
  42. Ruehl, W. W., Marrs, C., Beard, M. K., Shokooki, V., Hinojoza, J. R., Banks, S., Bieber, D. & Mattick, J. S. (1993). Q pili enhance the attachment of Moraxella bovis to bovine corneas in vitro. Mol Microbiol 7, 285-288.[CrossRef] [Google Scholar]
  43. Sambrook, J., Fritsch, E. F. & Maniatis, T. (1989).Molecular Cloning: a Laboratory Manual, 2nd edn. Cold Spring Harbor, NY: Cold Spring Harbor Laboratory.
  44. Shi, W., Ngok, F. K. & Zusman, D. R. (1996). Cell density regulates cellular reversal frequency in Myxococcus xanthus. Proc Natl Acad Sci USA 93, 4142-4146.[CrossRef] [Google Scholar]
  45. Stone, B. J. & Abu Kwaik, Y. (1998). Expression of multiple pili by Legionella pneumophila: identification and characterization of a type IV pilin gene and its role in adherence to mammalian and protozoan cells. Infect Immun 66, 1768-1775. [Google Scholar]
  46. Todd, W. J., Wray, G. P. & Hitchcock, P. J. (1984). Arrangement of pili in colonies of Neisseria gonorrhoeae. J Bacteriol 159, 312-320. [Google Scholar]
  47. Wall, D. & Kaiser, D. (1998). Alignment enhances the cell-to-cell transfer of pilus phenotype. Proc Natl Acad Sci USA 95, 3054-3058.[CrossRef] [Google Scholar]
  48. Wall, D., Wu, S. S. & Kaiser, D. (1998). Contact stimulation of Tgl and type IV pili in Myxococcus xanthus. J Bacteriol 180, 759-761. [Google Scholar]
  49. Wall, D., Kolenbrander, P. E. & Kaiser, D. (1999). The Myxococcus xanthuspilQ (sglA) gene encodes a secretin homolog required for type IV pilus biogenesis, social motility, and development. J Bacteriol 181, 24-33. [Google Scholar]
  50. Watson, A. A., Alm, R. A. & Mattick, J. S. (1996a). Identification of a gene, pilF, that is required for type 4 fimbrial biogenesis and twitching motility in Pseudomonas aeruginosa. Gene 180, 49-56.[CrossRef] [Google Scholar]
  51. Watson, A. A., Mattick, J. S. & Alm, R. A. (1996b). Functional expression of heterologous type 4 fimbriae in Pseudomonas aeruginosa. Gene 175, 143-150.[CrossRef] [Google Scholar]
  52. Whitchurch, C. B., Alm, R. A. & Mattick, J. S. (1996). Co-ordinate regulation of fimbrial function and alginate production in Pseudomonas aeruginosa. Proc Natl Acad Sci USA 93, 9839-9843.[CrossRef] [Google Scholar]
  53. Wu, S. S. & Kaiser, D. (1995). Genetic and functional evidence that type IV pili are required for social gliding motility in Myxococcus xanthus. Mol Microbiol 18, 547-558.[CrossRef] [Google Scholar]
  54. Wu, S. S. & Kaiser, D. (1997). Regulation of expression of the pilA gene in Myxococcus xanthus. J Bacteriol 179, 7748-7758. [Google Scholar]
  55. Wu, S. S., Wu, J. & Kaiser, D. (1997). The Myxococcus xanthuspilT locus is required for social gliding motility although pili are still produced. Mol Microbiol 23, 109-121.[CrossRef] [Google Scholar]

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