title: Heat shock and cold shock treatments affect the survival of Listeria monocytogenes and Salmonella Typhimurium exposed to disinfectants.
abstract: The foodborne pathogens Listeria monocytogenes and Salmonella Typhimurium were subjected to heat shock at 48°C for 10 and 30 min, respectively, and then cold shocked at 15°C for 3 h. The effect of these shocks on the viability of test organisms exposed to chlorine  dioxide and quaternary ammonium compounds was then determined. After exposure to the disinfectants, the viable population of each test organism, regardless of heat shock or cold shock treatment, decreased as the exposure period was extended. Both heat shock and cold shock treatments reduced  the susceptibility of L. monocytogenes to both disinfectants at 25°C. However, for Salmonella Typhimurium, exposure to the chlorine dioxide disinfectant or quaternary ammonium compounds at 25°C significantly reduced (P < 0.05) survival of heat-shocked cells  but significantly increased (P < 0.05) survival of cold-shocked cells compared with control cells. Survival of both L. monocytogenes and Salmonella Typhimurium generally was reduced after exposure to disinfectants at 40°C compared with 25°C.
authors.affiliation: Graduate Institute of Food Science and Technology, National Taiwan University, Taipei, Taiwan.
authors.forename: Meng-Hsuan
authors.initials: MH
authors.lastname: Lin
authors.forename: Ming-Lun
authors.initials: ML
authors.lastname: Chiang
authors.forename: Chorng-Liang
authors.initials: CL
authors.lastname: Pan
authors.forename: Cheng-Chun
authors.initials: CC
authors.lastname: Chou
mesh_terms: D003080:Cold Temperature; D015169:Colony Count, Microbial; D003257:Consumer Product Safety; D004202:Disinfectants / Q000494:pharmacology*; D005506:Food Contamination / Q000517:prevention & control; D005516:Food Microbiology; D006358:Hot Temperature; D006801:Humans; D008089:Listeria monocytogenes / Q000187:drug effects / Q000502:physiology*; D050296:Microbial Viability; D012486:Salmonella typhimurium / Q000187:drug effects / Q000502:physiology*
chemical_list: D004202:Disinfectants