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ARS Home » Research » Publications at this Location » Publication #212944
Title: Quantitative Assessment of Disinfectant Activity Against Listeria monocytogenes Biofilms Under Flow Conditions

Author
item Arnold, Judy
item KRAMER, S - STERILEX CORP
item ZAMBELLI-WEINER, A - STERILEX CORP

Submitted to: Association Official Analytical Chemists Annual Intrl Meeting & Exposition
Publication Type: Abstract Only
Publication Acceptance Date: 8/8/2007
Publication Date: 9/19/2007
Citation: Arnold, J.W., Kramer, S., Sambelli-Warner, A. 2007. Quantitative Assessment of Disinfectant Activity Against Listeria monocytogenes Biofilms Under Flow Conditions. Association Official Analytical Chemists Annual Intrl Meeting & Exposition. P-901, P. 28.

Interpretive Summary:

Technical Abstract: Listeria monocytogenes has a high mortality in humans and is responsible for most food recalls involving bacterial contamination. Our objective was to develop methods to quantitatively assess the pathogen under flow conditions to mimic wet food processing. A reactor was used to grow the bacteria on coupons. After 24 and 48 h, biofilm growth was scraped into trypticase soy broth, and the suspension was homogenized. An equal portion of coupons was measured for cell growth by APC and for biofilm production by a modified crystal violet assay. The assay resulted in different t groupings than the cell density. The density (log10cfu/ml) was 8.01 and 8.03, at 24 and 48 h. Assay results were variable, with std dev ranging from 0.156 to 0.394. This is the first use of the crystal violet assay for measurement of L. monocytogenes biofilms on stainless steel. The methods are applicable to other bacteria and substrata.