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ARS Home » Pacific West Area » Albany, California » Western Regional Research Center » Produce Safety and Microbiology Research » Research » Publications at this Location » Publication #374520

Research Project: Ecology and Detection of Human Pathogens in the Produce Production Continuum

Location: Produce Safety and Microbiology Research

Title: Strain specific response of Escherichia coli biofilms to chlorine dioxide

item Lacombe, Alison
item Wu, Vivian
item Bridges, David

Submitted to: International Association for Food Protection
Publication Type: Abstract Only
Publication Acceptance Date: 4/2/2020
Publication Date: N/A
Citation: N/A

Interpretive Summary: Chlorine dioxide is an important industrial sanitizer for food processing. It has known efficacy against pathogenic E. coli especially when it is encased in a biofilm. However, biofilms are very complex because their multidimensional nature. To further complicate matters, different strains of E. coli are less susceptible to sanitizers. This paper investigates the susceptibility of different strains of pathogenic E.coli individually and in combinations. The result of this study demonstrate that there are critical difference in strains when exposed to chlorine dioxide. These differences have serious implication for food safety.

Technical Abstract: Introduction: Chlorine dioxide (ClO2) is a standard sanitizer for foods and food contact surfaces. Aqueous ClO2 has proven efficacy against E. coli biofilms, which are a continuous source of contamination in the processing environment. However, little is known about E. coli’s behavior in biofilms and if generic serotypes are robust as other serotypes when treated with ClO2. Methods: This study investigated four STECs and one generic E. coli (E. coli O45 RM:13752; E. coli O157:H7 RM:18959; E. coli O157:H7 ATCC:43888 stx-; E. coli K-12 ATCC:13706; E. coli O145 RM:10808). The strains were inoculated individually or combined in a cocktail in a 24 well plate. After a 72-hour incubation at 25°C, planktonic cells were aspirated off, and the well was washed twice with peptone water (PW). The remaining biofilm was exposed to either distilled water (control) or 10ppm ClO2 for 10 minutes. After treatment, cells were enumerated on MacConkey's Sorbitol Agar.