P2-150 Effectiveness of Chemical Intervention Treatments against Escherichia coli O157:H7, Non-O157 STEC, Listeria monocytogenes, and Salmonella

Tuesday, July 30, 2013
Exhibit Hall (Charlotte Convention Center)
Amanda Svoboda, Iowa State University, Ames, IA
Aubrey Mendonca, Iowa State University, Ames, IA
Angela Shaw, Iowa State University, Ames, IA
Introduction: A recent increase in consumption of fruits and vegetables has been associated with an increased number of foodborne illness outbreaks linked to these products.  As a result, safe and effective sanitizing interventions must be identified for the treatment of produce to destroy foodborne pathogens within the industry.      

Purpose: In this study, experiments were conducted to determine the effectiveness of six different categories of chemical intervention treatments against foodborne pathogens in broth. Chemical interventions tested included sodium hypochlorite, hydrogen peroxide, liquid chlorine dioxide, peroxyacetic acid/hydrogen peroxide combinations, organic acid combinations, and quaternary ammonium. 

Methods: The chemical products were tested against: Escherichia coli O157:H7, Listeria monocytogenes, Salmonella, and a cocktail of non-O157 STEC (O26, O45, O103, O111, O121, and O145) in broth. Treatments were applied to suspensions of each pathogen at various concentrations, and log reductions were determined.

Results: There were significant differences observed between treatments (P<0.05).  The most effective categories of sanitizers were hydrogen peroxide, liquid chlorine dioxide and peroxyacetic acid/hydrogen peroxide with 8-9 log CFU/ml reductions for E. coli O157:H7, Listeria monocytogenes, Salmonella, and non-O157 STEC.  The sodium hypochlorite and quaternary ammonium products resulted in 4-6 log CFU/ml reductions depending on the foodborne pathogen.  The organic acid combination product was least effective with reductions of 3-5 log CFU/ml depending on the foodborne pathogen. 

Significance: Based on study results, we determine that hydrogen peroxide, liquid chlorine dioxide and peroxyacetic acid/hydrogen peroxide products were most effective against the foodborne pathogens of concern within broth. The information from this study will be utilized by researchers to conduct further analysis on the effect of chemical treatments against foodborne pathogens on whole fruit. This study also may be of interest to public health personnel and the fruits and vegetable industry, for the control of these pathogens in the food supply.