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Cells and Materials

Biofilm

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Full-Text Articles in Biomedical Engineering and Bioengineering

Biofilms In Dental Unit Waterlines: Ultrastructural And Cytochemical Analysis, J. Barbeau, C. Avezard, E. Faucher, S. Zalzal, A. P. Prévost Jan 1997

Biofilms In Dental Unit Waterlines: Ultrastructural And Cytochemical Analysis, J. Barbeau, C. Avezard, E. Faucher, S. Zalzal, A. P. Prévost

Cells and Materials

Dental unit waterlines are heavily colonized by bacteria which contaminate the water used to perform intra-oral, and sometimes invasive, procedures. There is little information on the nature of the biofilm colonizing the flexible plastic tubing used to supply water to the different handpieces. We have therefore undertaken quantitative microbial analysis and ultrastructural studies of these biofilms by direct counting with the epifluorescent filter technique and by transmission and scanning electron microscopy after staining with ruthenium red and periodic acid-thiosemicarbazide-silver proteinate to visualize the composition and the distribution of exopolysaccharides and intracellular polysaccharides. The biofilm was revealed as a non-uniform structure …


Laboratory Growth Systems In Biofilm Research, Julian W. T. Wimpenny Jan 1996

Laboratory Growth Systems In Biofilm Research, Julian W. T. Wimpenny

Cells and Materials

The huge variety of ecosystems that we collectively refer to as "biofilm" is reflected by the numerous different systems available to grow them in the laboratory. The relationship between in situ systems, microcosms and laboratory models is defined and discussed. The first two represent holistic approaches designed to assess the structure and function of particular biofilms: the last is analytical and reductionist, aiming to isolate specific functions of biofilms in order to understand properties that can apply to biofilm in general. Properties of a model can be completely understood whilst this is unlikely with natural ecosystems because of the possibility …


Biofilm Mediated Calculus Formation In The Urinary Tract, Robert J. C. Mclean, David J. Stickler, J. Curtis Nickel Jan 1996

Biofilm Mediated Calculus Formation In The Urinary Tract, Robert J. C. Mclean, David J. Stickler, J. Curtis Nickel

Cells and Materials

Mineralization and subsequent calculus formation is a common complication of biofilm infections. In the urinary tract, these infected calculi often arise from infections by urease-producing bacteria. Ammonia, liberated by bacterial urease activity, increases urine pH, resulting in the precipitation of Ca and Mg as carbonateapatite {Ca10(PO4,CO3)6(OH,CO3)2} and struvite (NH4MgP04·6H2O). These minerals become entrapped in the organic matrix which surrounds the infecting organisms and ultimately grow into mature calculi. When the causative organisms grow on urinary catheters and stents, the resulting mineralization can …