These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Analysis of outer membrane ultrastructure of pathogenic Treponema and Borrelia species by freeze-fracture electron microscopy.
    Author: Walker EM, Borenstein LA, Blanco DR, Miller JN, Lovett MA.
    Journal: J Bacteriol; 1991 Sep; 173(17):5585-8. PubMed ID: 1885536.
    Abstract:
    We analyzed the outer membrane (OM) ultrastructure of four pathogenic members of the family Spirochaetaceae by freeze fracture. The OM of Treponema pallidum subsp. pertenue contained a low intramembranous particle concentration, indicating that it contains few OM transmembrane proteins. The concave OM fracture faces of Treponema hyodysenteriae and Borrelia burgdorferi contained dense populations of particles, typical of gram-negative organisms. A relatively low concentration of particles which were evenly divided between a small and a large species was present in the concave OM fracture face of Borrelia hermsii; the convex OM fracture face contained only small particles. As for gram-negative bacteria, the convex OM fracture face particle concentrations of these pathogens were low. These spirochetes cleaved preferentially within the OM, in contrast to typical gram-negative bacteria, which tend to fracture within the inner membrane. The OM ultrastructure of T. pallidum subsp. pertenue provides an explanation for the lack of antigenicity of the treponemal surface and may reflect a mechanism by which this pathogen evades the host immune response.
    [Abstract] [Full Text] [Related] [New Search]