Session: Analytical Division Poster:

Biofilms are a leading cause of hospital acquired infections, which are often initiated on medical tubing (e.g. catheters) where microorganisms can easily attach and develop extracellular polymeric matrices (ECM). Understanding and quantifying biofilms are critical to drug development and patient care. However, current standard methods for their detection and quantification are limited by factors such as small-colony variants, non-culturable microorganisms and false positives resulting from the inability to differentiate between live and dead cells. In addition, methods are rarely performed together, resulting in incomplete analyses of cellular and extracellular components. There is little evidence of a comprehensive culture-independent method for the detection and quantification of biofilms on catheter surfaces. We propose an array of non-strain-specific methods for quantifying cellular and ECM components of biofilms attached to catheter surfaces by assessing total protein (modified Lowry), total biomass (quantitative polymerase chain reaction), cellular activity (ATP luminescence), and extracellular polymeric substances (Periodic Acid-Schiff). Four clinical isolates (Pseudomonas aeruginosa, Staphylococcus aureus, methicillin resistant-Staphylococcus aureus, Candida albicans) and two catheter types were tested. Results showed that each method was able to quantify cells and evaluate catheter performance. The reproducibility, broad strain-specificity culture independence, and high throughput capabilities of this approach makes it potentially valuable for the quality assessment of materials such as catheters, implants, intravenous fluid bags, and ventilators in clinical settings.

Brian McVerry

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