title: Role of cellulose in protecting Shiga toxin-producing Escherichia coli against osmotic and chlorine stress.
abstract: This study was undertaken to determine the role of cellulose in protecting Shiga toxin-producing Escherichia coli (STEC) against osmotic and chlorine treatments. STEC cells producing cellulose (19B and 49B) and their respective cellulose-deficient counterparts (19D or 49D) were subjected to osmotic (1, 2, and 3 M NaCl) or chlorine (25, 50, and 100 μg/ml sodium hypochlorite) treatments. The survival of STEC cells was determined at different treatment intervals. Populations of 19B cells were significantly higher (P < 0.05) than those of 19D cells at all sampling intervals for the chlorine treatments, at 24- to 48-h intervals for the 1 M NaCl treatment, and at 9- to 48-h intervals for the 2 M NaCl treatment. Significant differences in populations of 49B and 49D cells were observed after 9, 36, and 48 h of treatment with 2 M NaCl and after 3, 12, 36, and 48 h of treatment with 3 M NaCl (P < 0.05). Populations of 49B cells were higher than those of 49D cells (P < 0.05) also after 5 to 10 min of treatment with 50 μg/ml sodium hypochlorite and 3 to 10 min of treatment with 100 μg/ml sodium hypochlorite. The protective effects conferred by cellulose may explain the greater survival of cellulose-producing STEC under adverse environmental conditions.
authors.affiliation: Department of Food Science and Technology, University of Georgia, Griffin, Georgia 30223, USA.
authors.forename: Byong K
authors.initials: BK
authors.lastname: Yoo
authors.forename: Jinru
authors.initials: J
authors.lastname: Chen
mesh_terms: D002482:Cellulose / Q000096:biosynthesis; D002713:Chlorine / Q000494:pharmacology*; D015169:Colony Count, Microbial; D004305:Dose-Response Relationship, Drug; D005516:Food Microbiology; D050296:Microbial Viability; D009995:Osmosis / Q000187:drug effects; D054323:Shiga-Toxigenic Escherichia coli / Q000254:growth & development* / Q000378:metabolism; D012965:Sodium Chloride / Q000494:pharmacology*; D013312:Stress, Physiological / Q000187:drug effects; D013997:Time Factors
chemical_list: D012965:Sodium Chloride; D002713:Chlorine; D002482:Cellulose