PMCCPMCCPMCC

Search tips
Search criteria 

Advanced

 
Logo of iaiPermissionsJournals.ASM.orgJournalIAI ArticleJournal InfoAuthorsReviewers
 
Infect Immun. Mar 1993; 61(3): 955–965.
PMCID: PMC302825
Ultrastructural analysis of attachment to and penetration of capillaries in the murine pons, midbrain, thalamus, and hypothalamus by Nocardia asteroides.
B L Beaman and S A Ogata
Department of Medical Microbiology and Immunology, University of California School of Medicine, Davis 95616.
Abstract
The attachment to and penetration of endothelial cells in the pons and midbrain (especially the substantia nigra) regions of the brains of BALB/c mice by log-phase Nocardia asteroides GUH-2 cells were determined by both scanning and transmission electron microscopic analysis. Within 15 min after exposure, the nocardiae attached to the surface of the endothelial cell membrane. This attachment occurred primarily at the growing tip of the nocardial filament, and the outermost layer of the nocardial cell wall had regions (electron-dense areas) that bound firmly to the cytoplasmic membrane of the host cell. There appeared to be specificity for this binding localized within the capillaries and arterioles because some regions had large numbers of bacteria bound, whereas adjacent areas had no bacterial cells. Nocardial filaments that attached by the apex induced a cuplike deformation of the endothelial cell membrane. This was followed by a rapid penetration of the endothelial cell so that within 25 min many of the bacteria were internalized within the host cell. These internalized bacteria remained within vesicles, and there was no ultrastructural evidence of damage to the nocardial cell during this process. Heat-killed GUH-2 cells still attached to endothelial surfaces (at a reduced frequency), but they did not penetrate into the endothelial cell. These data suggest that brain-invasive nocardiae possess both an adhesin for attachment to the membrane of endothelial cells and an invasion factor that promotes nocardial penetration of these cells.
Full text
Full text is available as a scanned copy of the original print version. Get a printable copy (PDF file) of the complete article (6.6M), or click on a page image below to browse page by page.
Articles from Infection and Immunity are provided here courtesy of
American Society for Microbiology (ASM)