title: Inactivation of Escherichia coli O157:H7 in biofilm on food-contact surfaces by sequential treatments of aqueous chlorine dioxide and drying.
abstract: We investigated the efficacy of sequential treatments of aqueous chlorine and chlorine dioxide and drying in killing Escherichia coli O157:H7 in biofilms formed on stainless steel, glass, plastic, and wooden surfaces. Cells attached to and formed a biofilm on wooden surfaces at significantly (P ≤ 0.05) higher levels compared with other surface types. The lethal activities of sodium hypochlorite (NaOCl) and aqueous chlorine dioxide (ClO₂) against E. coli O157:H7 in a biofilm on various food-contact surfaces were compared. Chlorine dioxide generally showed greater lethal activity than NaOCl against E. coli O157:H7 in a biofilm on the same type of surface. The resistance of E. coli O157:H7 to both sanitizers increased in the order of wood>plastic>glass>stainless steel. The synergistic lethal effects of sequential ClO₂ and drying treatments on E. coli O157:H7 in a biofilm on wooden surfaces were evaluated. When wooden surfaces harboring E. coli O157:H7 biofilm were treated with ClO₂ (200 μg/ml, 10 min), rinsed with water, and subsequently dried at 43% relative humidity and 22 °C, the number of E. coli O157:H7 on the surface decreased by an additional 6.4 CFU/coupon within 6 h of drying. However, when the wooden surface was treated with water or NaOCl and dried under the same conditions, the pathogen decreased by only 0.4 or 1.0 log CFU/coupon, respectively, after 12 h of drying. This indicates that ClO₂ treatment of food-contact surfaces results in residual lethality to E. coli O157:H7 during the drying process. These observations will be useful when selecting an appropriate type of food-contact surfaces, determining a proper sanitizer for decontamination, and designing an effective sanitization program to eliminate E. coli O157:H7 on food-contact surfaces in food processing, distribution, and preparation environments.
authors.affiliation: Department of Biotechnology, Korea University, Anam-dong, Sungbuk-ku, Seoul 136-701, Republic of Korea.
authors.forename: Jihyun
authors.initials: J
authors.lastname: Bang
authors.affiliation: Department of Biotechnology, Korea University, Anam-dong, Sungbuk-ku, Seoul 136-701, Republic of Korea.
authors.forename: Ayoung
authors.initials: A
authors.lastname: Hong
authors.affiliation: Division of Human Environmental Sciences, Wonkwang University, Shinyong-dong, Iksan, Jeonbuk 570-749, Republic of Korea.
authors.forename: Hoikyung
authors.initials: H
authors.lastname: Kim
authors.affiliation: Center for Food Safety and Department of Food Science and Technology, University of Georgia, 1109 Experiment Street, Griffin, GA 30223-2797, USA.
authors.forename: Larry R
authors.initials: LR
authors.lastname: Beuchat
authors.affiliation: Department of Biotechnology, Korea University, Anam-dong, Sungbuk-ku, Seoul 136-701, Republic of Korea.
authors.forename: Min Suk
authors.initials: MS
authors.lastname: Rhee
authors.affiliation: BK 21 Plus Graduate Program, Department of Animal Science and Institute Agricultural Science and Technology, Chonbuk National University, Jeonju 561-756, Republic of Korea.
authors.forename: Younghoon
authors.initials: Y
authors.lastname: Kim
authors.affiliation: Department of Biotechnology, Korea University, Anam-dong, Sungbuk-ku, Seoul 136-701, Republic of Korea. Electronic address: escheri@korea.ac.kr.
authors.forename: Jee-Hoon
authors.initials: JH
authors.lastname: Ryu
mesh_terms: D000890:Anti-Infective Agents / Q000494:pharmacology; D018441:Biofilms / Q000187:drug effects*; D017606:Chlorine Compounds / Q000494:pharmacology*; D015169:Colony Count, Microbial; D003890:Desiccation; D004926:Escherichia coli / Q000187:drug effects; D019453:Escherichia coli O157 / Q000187:drug effects*; D005511:Food Handling / Q000295:instrumentation*; D005516:Food Microbiology / Q000379:methods*; D005898:Glass; D050296:Microbial Viability / Q000187:drug effects*; D010087:Oxides / Q000494:pharmacology*; D010969:Plastics; D012973:Sodium Hypochlorite / Q000494:pharmacology; D013193:Stainless Steel; D014867:Water; D014934:Wood / Q000382:microbiology
chemical_list: D000890:Anti-Infective Agents; D017606:Chlorine Compounds; D010087:Oxides; D010969:Plastics; D014867:Water; D013193:Stainless Steel; C025109:chlorine dioxide; D012973:Sodium Hypochlorite
keywords: Biofilm; Chlorine dioxide; Drying; Escherichia coli O157:H7; Food-contact surface