title: Effect of slightly acidic electrolyzed water for inactivating Escherichia coli O157:H7 and Staphylococcus aureus analyzed by transmission electron microscopy.
abstract: The use of different available chlorine concentrations (ACCs) of slightly acidic electrolyzed water (SAEW; 0.5 to 30 mg/liter), different treatment times, and different temperatures for inactivating Escherichia coli O157:H7 and Staphylococcus aureus was evaluated. The morphology of both pathogens also was analyzed with transmission electron microscopy. A 3-min treatment with SAEW (pH 6.0 to 6.5) at ACCs of 2 mg/liter for E. coli O157:H7 and 8 mg/liter for S. aureus resulted in 100% inactivation of two cultures (7.92- to 8.75-log reduction) at 25°C. The bactericidal activity of SAEW was independent of the treatment time and temperature at a higher ACC (P > 0.05). E. coli O157:H7 was much more sensitive than S. aureus to SAEW. The morphological damage to E. coli O157:H7 cells by SAEW was significantly greater than that to S. aureus cells. At an ACC as high as 30 mg/liter, E. coli O157:H7 cells were damaged, but S. aureus cells retained their structure and no cell wall damage or shrinkage was observed. SAEW with a near neutral pH may be a promising disinfectant for inactivation of foodborne pathogens.
authors.affiliation: The Key Laboratory of Bio-environmental Engineering, China Agricultural University, P.O. Box 67, Beijing 100083, People's Republic of China.
authors.forename: Songjian
authors.initials: S
authors.lastname: Nan
authors.forename: L I
authors.initials: LI
authors.lastname: Yongyu
authors.forename: L I
authors.initials: LI
authors.lastname: Baoming
authors.forename: Chaoyuan
authors.initials: C
authors.lastname: Wang
authors.forename: Xiaodong
authors.initials: X
authors.lastname: Cui
authors.forename: Wei
authors.initials: W
authors.lastname: Cao
mesh_terms: D003257:Consumer Product Safety; D004202:Disinfectants / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D019453:Escherichia coli O157 / Q000187:drug effects* / Q000648:ultrastructure; D005506:Food Contamination / Q000032:analysis / Q000517:prevention & control; D006861:Hydrogen Peroxide / Q000494:pharmacology*; D046529:Microscopy, Electron, Transmission; D013211:Staphylococcus aureus / Q000187:drug effects* / Q000648:ultrastructure; D013696:Temperature; D013997:Time Factors
chemical_list: D004202:Disinfectants; C118085:superoxidized water; D006861:Hydrogen Peroxide