title: Exposure to high hydrostatic pressure rapidly selects for increased RpoS activity and general stress-resistance in Escherichia coli O157:H7.
abstract: Exposure to high hydrostatic pressure (HHP) is increasingly being used in food preservation as a non-thermal pasteurization process, and its further implementation necessitates a more thorough understanding of bacterial resistance development and intraspecies variability with regard to inactivation by HHP. In this report, we discovered that exposure to high hydrostatic pressure stress can rapidly select for strongly increased RpoS activity in a hypersensitive Escherichia coli O157:H7 strain (ATCC 43888), leading to a simultaneous increase in HHP and heat resistance. Moreover, the level of RpoS activity correlated well with the original hypersensitivity and the extent of acquired HHP resistance, and extremely HHP-resistant mutants of ATCC 43888 clearly incurred a number of additional RpoS-dependent phenotypes. These findings suggest that implementation of novel processing techniques in the food production chain can readily affect the physiology of food-borne pathogens.
authors.affiliation: Laboratory of Food Microbiology and Leuven Food Science and Nutrition Research Centre (LFoRCe), Department of Microbial and Molecular Systems (M(2)S), Faculty of Bioscience Engineering, KU Leuven, Kasteelpark Arenberg 22, B-3001 Leuven, Belgium.
authors.forename: Dietrich
authors.initials: D
authors.lastname: Vanlint
authors.forename: Nele
authors.initials: N
authors.lastname: Rutten
authors.forename: Sander K
authors.initials: SK
authors.lastname: Govers
authors.forename: Chris W
authors.initials: CW
authors.lastname: Michiels
authors.forename: Abram
authors.initials: A
authors.lastname: Aertsen
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D019453:Escherichia coli O157 / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D005519:Food Preservation / Q000379:methods*; D006358:Hot Temperature; D006874:Hydrostatic Pressure; D009154:Mutation; D012808:Sigma Factor / Q000235:genetics / Q000378:metabolism*; D013312:Stress, Physiological / Q000235:genetics / Q000502:physiology*
chemical_list: D001426:Bacterial Proteins; D012808:Sigma Factor; C069567:sigma factor KatF protein, Bacteria