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Role of the alternative sigma factors sigmaE and sigmaS in survival of Salmonella enterica serovar Typhimurium during starvation, refrigeration and osmotic shock.
Microbiology (Reading). 2007 Jan; 153(Pt 1):263-9.M

Abstract

The ability of Salmonella enterica serovar Typhimurium to survive environmental stress requires specific, coordinated, responses, which induce resistance to the stress condition. This study investigated the relative contribution of sigmaE and sigmaS, the sigma factors regulating extracytoplasmic and general stress response functions, respectively, to survival at low temperature and also in media of differing osmotic strength, conditions relevant to food preservation. To determine if low-temperature storage is a signal for sigmaE- and sigmaS-mediated survival, the ability of S. Typhimurium rpoE, rpoS and rpoE/rpoS mutants to survive in a saline starvation-survival model at a refrigeration temperature (4.5 degrees C) was examined. Under these conditions, the rpoE mutant was significantly (P<0.05) compromised compared to the parent and to an rpoS mutant. The double mutant in rpoE and rpoS displayed a cumulative defect in survival. In hyperosmotic environments (low aw) containing 6 % NaCl and at refrigeration temperature, both sigma factors were important for maximum survival but sigmaS played the dominant role. Analysis of the metabolic activity of starved populations at 4.5 and 37 degrees C revealed significantly (P<0.001) elevated electron-transport system activity in mutants in rpoE and rpoS, indicating a role for sigmaE- and sigmaS-regulated genes in maintaining energy homeostasis. Together these data demonstrate that sigmaE and sigmaS are important for survival of S. Typhimurium in conditions encountered during food processing and that the relative contribution of sigmaE and sigmaS is critically dependent on the precise nature of the stress.

Authors+Show Affiliations

Division of Veterinary Pathology, Infection and Immunity, School of Clinical Veterinary Science, University of Bristol, Langford, Bristol BS40 5DU, UK.No affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

17185555

Citation

McMeechan, Alisdair, et al. "Role of the Alternative Sigma Factors sigmaE and sigmaS in Survival of Salmonella Enterica Serovar Typhimurium During Starvation, Refrigeration and Osmotic Shock." Microbiology (Reading, England), vol. 153, no. Pt 1, 2007, pp. 263-9.
McMeechan A, Roberts M, Cogan TA, et al. Role of the alternative sigma factors sigmaE and sigmaS in survival of Salmonella enterica serovar Typhimurium during starvation, refrigeration and osmotic shock. Microbiology (Reading). 2007;153(Pt 1):263-9.
McMeechan, A., Roberts, M., Cogan, T. A., Jørgensen, F., Stevenson, A., Lewis, C., Rowley, G., & Humphrey, T. J. (2007). Role of the alternative sigma factors sigmaE and sigmaS in survival of Salmonella enterica serovar Typhimurium during starvation, refrigeration and osmotic shock. Microbiology (Reading, England), 153(Pt 1), 263-9.
McMeechan A, et al. Role of the Alternative Sigma Factors sigmaE and sigmaS in Survival of Salmonella Enterica Serovar Typhimurium During Starvation, Refrigeration and Osmotic Shock. Microbiology (Reading). 2007;153(Pt 1):263-9. PubMed PMID: 17185555.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Role of the alternative sigma factors sigmaE and sigmaS in survival of Salmonella enterica serovar Typhimurium during starvation, refrigeration and osmotic shock. AU - McMeechan,Alisdair, AU - Roberts,Mark, AU - Cogan,Tristan A, AU - Jørgensen,Frieda, AU - Stevenson,Andrew, AU - Lewis,Claire, AU - Rowley,Gary, AU - Humphrey,Tom J, PY - 2006/12/23/pubmed PY - 2007/2/24/medline PY - 2006/12/23/entrez SP - 263 EP - 9 JF - Microbiology (Reading, England) JO - Microbiology (Reading) VL - 153 IS - Pt 1 N2 - The ability of Salmonella enterica serovar Typhimurium to survive environmental stress requires specific, coordinated, responses, which induce resistance to the stress condition. This study investigated the relative contribution of sigmaE and sigmaS, the sigma factors regulating extracytoplasmic and general stress response functions, respectively, to survival at low temperature and also in media of differing osmotic strength, conditions relevant to food preservation. To determine if low-temperature storage is a signal for sigmaE- and sigmaS-mediated survival, the ability of S. Typhimurium rpoE, rpoS and rpoE/rpoS mutants to survive in a saline starvation-survival model at a refrigeration temperature (4.5 degrees C) was examined. Under these conditions, the rpoE mutant was significantly (P<0.05) compromised compared to the parent and to an rpoS mutant. The double mutant in rpoE and rpoS displayed a cumulative defect in survival. In hyperosmotic environments (low aw) containing 6 % NaCl and at refrigeration temperature, both sigma factors were important for maximum survival but sigmaS played the dominant role. Analysis of the metabolic activity of starved populations at 4.5 and 37 degrees C revealed significantly (P<0.001) elevated electron-transport system activity in mutants in rpoE and rpoS, indicating a role for sigmaE- and sigmaS-regulated genes in maintaining energy homeostasis. Together these data demonstrate that sigmaE and sigmaS are important for survival of S. Typhimurium in conditions encountered during food processing and that the relative contribution of sigmaE and sigmaS is critically dependent on the precise nature of the stress. SN - 1350-0872 UR - https://www.unboundmedicine.com/medline/citation/17185555/Role_of_the_alternative_sigma_factors_sigmaE_and_sigmaS_in_survival_of_Salmonella_enterica_serovar_Typhimurium_during_starvation_refrigeration_and_osmotic_shock_ L2 - http://mic.microbiologyresearch.org/pubmed/content/journal/micro/10.1099/mic.0.29235-0 DB - PRIME DP - Unbound Medicine ER -