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Chapter 1
[119] and flow cell reactors have been adapted and fitted with a glass
chambers into the devices to facilitate real-time imaging [102]. This
method involves staining the bacterial cells with a fluorescent dye before
inoculating the reactor and assessing the accumulation of cells over time
using microscopy.
The Center for Disease Control and Prevention Biofilm Reactor (CBR) has
been extensively used in recent studies [117, 120-124]. This continuous
flow method was chosen for this research as it allows biofilm formation on
multiple surfaces simultaneously. The CBR also has the benefits of
incorporating sheer stress and examination of spatial growth (through
microscopy) and evaluation of viable cells (though plate counts). The CDC
reactor was the first model approved by the American Society for Testing
Materials (ASTM) for the development of biofilm on surfaces [117]. As of
2012, both the CDC biofilm reactor (ASTM standard number E2871-
12)[125] and the MBEC Assay (ASTM standard number E2799-12)[126]
have been approved by ASTM. The CBR is discussed in greater detail in
chapter two.
1.16. Biocides and Disinfectants
The term biocide is inclusive of a broad range of chemical agents such as
disinfectants, antiseptics, herbicides, preservatives, insecticides, fungicides,
enzymes and probiotic substances such as Lactobacillus species [127-128].
The term biocide does not generally include antibiotics [128-129] which
usually target a specific organism by use of a compound at a low
concentrations while biocides generally target all organisms through the
use of high concentration of the compound. A disinfectant can be classified
as a product that reduces the number of viable organisms on a surface
[129]. Because of extensive variability in tests it is difficult to develop a
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