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Global genome response of Escherichia coli O157:H7 Sakai during dynamic changes in growth kinetics induced by an abrupt temperature downshift


King, T and Kocharunchitt, C and Gobius, K and Bowman, JP and Ross, T, Global genome response of Escherichia coli O157:H7 Sakai during dynamic changes in growth kinetics induced by an abrupt temperature downshift, PLoS One, 9, (6) Article e99627. ISSN 1932-6203 (2014) [Refereed Article]


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Licensed under Creative Commons Attribution 3.0 Unported (CC BY 3.0)

DOI: doi:10.1371/journal.pone.0099627


Escherichia coli O157:H7 is a mesophilic food-borne pathogen. We investigated the growth kinetics of E. coli O157:H7 Sakai during an abrupt temperature downshift from 35C to either 20C, 17C, 14C or 10C; as well as the molecular mechanisms enabling growth after cold stress upon an abrupt downshift from 35C to 14C in an integrated transcriptomic and proteomic analysis. All downshifts caused a lag period of growth before growth resumed at a rate typical of the post-shift temperature. Lag and generation time increased with the magnitude of the shift or with the final temperature, while relative lag time displayed little variation across the test range. Analysis of time-dependent molecular changes revealed, in keeping with a decreased growth rate at lower temperature, repression of genes and proteins involved in DNA replication, protein synthesis and carbohydrate catabolism. Consistent with cold-induced remodelling of the bacterial cell envelope, alterations occurred in the expression of genes and proteins involved in transport and binding. The RpoS regulon exhibited sustained induction confirming its importance in adaptation and growth at 14C. The RpoE regulon was transiently induced, indicating a potential role for this extracytoplasmic stress response system in the early phase of low temperature adaptation during lag phase. Interestingly, genes previously reported to be amongst the most highly up-regulated under oxidative stress were consistently down-regulated. This comprehensive analysis provides insight into the molecular mechanisms operating during adaptation of E. coli to growth at low temperature and is relevant to its physiological state during chilling in foods, such as carcasses.

Item Details

Item Type:Refereed Article
Keywords:E. coli, temperature downshift, proteomics, transcriptomics, stress response
Research Division:Biological Sciences
Research Group:Microbiology
Research Field:Bacteriology
Objective Division:Expanding Knowledge
Objective Group:Expanding knowledge
Objective Field:Expanding knowledge in the biological sciences
UTAS Author:Kocharunchitt, C (Mr Chawalit Kocharunchitt)
UTAS Author:Bowman, JP (Associate Professor John Bowman)
UTAS Author:Ross, T (Professor Tom Ross)
ID Code:97070
Year Published:2014
Web of Science® Times Cited:11
Deposited By:Tasmanian Institute of Agriculture
Deposited On:2014-12-02
Last Modified:2017-11-06
Downloads:240 View Download Statistics

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