Submitted to: Association Official Analytical Chemists Annual Intrl Meeting & Exposition
Publication Type: Abstract Only
Publication Acceptance Date: 7/29/2005
Publication Date: 9/13/2005
Citation: Arnold, J.W., Delaubenfels, E. 2005. Assessment of disinfectant activity against listeria monocytogenes by the aoac use-dilution method. Association Official Analytical Chemists Annual Intrl Meeting & Exposition. Interpretive Summary:
Technical Abstract: Effective intervention strategies are needed to reduce the risk of foodborne disease caused by bacterial pathogens, such as Listeria monocytogenes. L. monocytogenes causes 20 deaths per 100 cases, and was responsible for most food product recalls for pathogen contamination during the past 18 months. The procedures for testing disinfectant activity against bacteria are described in the Official Methods of Analysis of the Association of Official Analytical Chemists (AOAC) as use-dilution methods 955.14, 955.15, and 964.02. The methods are performed for surface disinfectant activity with three bacteria, Staphylococcus aureus, Salmonella cholerasuis, and Pseudomonas aeruginosa, used as test organisms. No standard methods are provided for L. monocytogenes. In this study, the use-dilution method was performed to measure the disinfectant activity of a quaternary ammonium compound with hydroperoxide ion against L. monocytogenes. Three broth culture and two plate media were tested for best growth, and brain heart infusion broth was selected for culture media. Aliquots of the test compound were placed into a series of test tubes. Stainless steel penicylinders were contaminated with L. monocytogenes and added separately to the tubes for five, ten, and 15 minutes. After exposure, the carriers were removed and placed into two series of D/E neutralization media. All tubes were incubated at 37°C for 48 hr and observed for growth. In three trials with two reps, the average phenol coefficient was 4.1. These technique-sensitive methods can provide quantitative data for comparison of disinfectant activity against L. monocytogenes.