C. Winters et al., SOME OBSERVATIONS ON THE STRUCTURE OF ENCRUSTING BIOFILMS OF PROTEUS-MIRABILIS ON URETHRAL CATHETERS, Cells and materials, 5(3), 1995, pp. 245-253
Citations number
30
Categorie Soggetti
Cell Biology","Medicine, Research & Experimental","Materials Science, Biomaterials
A physical model of the bladder has been used to study the process of
urinary catheter encrustation. Techniques have been devised for the pr
eparation of sections through these encrustations in situ on the lumin
al surfaces of catheters and for mapping the distribution of calcium a
nd magnesium in the biofilms. Transmission electron microscopy on thes
e sections showed struvite-like crystals lying in the matrix and in di
rect contact with the catheter surface. Calcium phosphate (''bioapatit
e'') was distributed throughout the film and many of these amorphous p
articles appear to have cells at their cores. Freeze-substituted secti
ons of biofilms also showed electron dense materials around cell-like
shapes and X-ray mapping and X-ray scanning transmission microscopy on
the catheter biofilms also indicate that mineralization-occurs around
the bacterial cells. These observations suggest that in catheterized
bladders infected by Proteus mirabilis, bacteria and crystals formed i
n the urine, adhere to the catheter. Further colonization and growth o
f the cells on the catheter and crystal surfaces produces the alkaline
biofilm which provides the conditions for continued encrustation. The
binding of crystals directly onto the catheter and the subsequent bac
terial colonization of these crystals has implications for attempts to
prevent encrustation by manufacturing catheters from biomaterials imp
regnated or coated with antibacterials.