title: Alternative sigma factor σE has an important role in stress tolerance of Yersinia pseudotuberculosis IP32953.
abstract: Yersinia pseudotuberculosis is an important pathogen that probably survives well in the modern food chain. However, little is known about the mechanisms that allow the growth of this pathogen in foods under stress conditions. The expression of rpoE encoding σ(E) was defined by quantitative real-time reverse transcription-PCR. Expression of rpoE was induced at 3°C, 37°C, and 42°C, under exposure to 3% NaCl, 3% ethanol, or high and low pH, in relation to its expression at the optimum growth temperature of 28°C of Y. pseudotuberculosis. Mutation of rpoE either impaired or abolished growth under stresses caused by low or high temperature, low pH, and ethanol. In addition, the growth temperature range of the mutant was significantly diminished compared to that of the wild-type strain IP32953. The results were confirmed with complementation of the mutant. Thus, σ(E) plays a significant role in the stress tolerance of Y. pseudotuberculosis IP32953 and probably contributes to the survival of this pathogen in the food chain.
authors.affiliation: Department of Food Hygiene and Environmental Health, Faculty of Veterinary Medicine, University of Helsinki, Helsinki, Finland.
authors.forename: Eveliina
authors.initials: E
authors.lastname: Palonen
authors.forename: Miia
authors.initials: M
authors.lastname: Lindström
authors.forename: Panu
authors.initials: P
authors.lastname: Somervuo
authors.forename: Hannu
authors.initials: H
authors.lastname: Korkeala
mesh_terms: D000431:Ethanol / Q000378:metabolism; D005516:Food Microbiology; D017353:Gene Deletion; D020869:Gene Expression Profiling; D015964:Gene Expression Regulation, Bacterial; D005816:Genetic Complementation Test; D006863:Hydrogen-Ion Concentration; D050296:Microbial Viability / Q000187:drug effects / Q000528:radiation effects; D060888:Real-Time Polymerase Chain Reaction; D012808:Sigma Factor / Q000235:genetics / Q000378:metabolism*; D012965:Sodium Chloride / Q000378:metabolism; D013312:Stress, Physiological; D013696:Temperature; D015011:Yersinia pseudotuberculosis / Q000187:drug effects / Q000235:genetics / Q000502:physiology* / Q000528:radiation effects
chemical_list: D012808:Sigma Factor; C063202:sporulation-specific sigma factors; D000431:Ethanol; D012965:Sodium Chloride