Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 2/18/2010
Publication Date: 7/17/2010
Citation: Netramai,S.,Rubino,M.,Auras,R.,Annous,B.,Matthews,K.2010.Efficacy of gaseous chlorine dioxide on inactivation of Escherichia coli O157:H7 on surfaces of artificially inoculated fresh-cut Romaine lettuce leaves [abstract].IFT.Chicago,IL.p.1. Interpretive Summary:
Technical Abstract: Efficacy of antimicrobial agents in inactivating pathogenic microorganisms on fresh and fresh-cut produce surfaces in limited by the accessibility of such agents to the produce surfaces where the microorganisms are residing. Other factors contribute to this problem include biofilm formation by the microorganisms within the inaccessible surface of the fresh produce. A biofilm is an aggregation of microorganisms encapsulated in a matrix of extracellular polymeric substances (EPS). It is an important survival mechanism for microorganisms, as the film creates a protected environment which allows the bacterial cells living within the biofilm to tolerate the harsh environment as well as the antimicrobial agents. Chlorine dioxide (ClO2) gas is one of the sanitizers reported to be able to reach such inaccessible sites on the produce surfaces and its ability to penetrate the biofilm protective layer which makes gives it a superior efficacy in inactivating bacterial cells in biofilm on produce surfaces. To study the antimicrobial effects of ClO2 gas on a biofilm, the surfaces of Romaine lettuce were inoculated with Escherichia coli O157:H7 and then were treated with 0.2 mg/L ClO2 for 15 min. The treatment gave up to 1.5 log reduction in pathogen population. The scanning electron microscope (SEM) pictures taken from both the untreated and ClO2-treated lettuce surfaces showed the noticeable reduction and damages to the biofilm structure following ClO2 treatment.