Stress Response and Regulatory Networks in Bacterial Foodborne Pathogens

A key effort in the Food safety Lab is to develop a better understanding of stress response systems and regulatory networks in bacterial pathogens and to translate this knowledge into improved control strategies for foodborne pathogens. Foodborne pathogens have to be able to adapt to diverse environmental and stress conditions during foodborne transmission, including food associated stresses (low pH, salt, low temperature) and host associated stresses (e.g., low pH in the stomach, oxidative stress). Our research not only provides a better understanding of the mechanisms used by bacteria to adapt to stressful and rapidly changing environments, but also provides knowledge that can be used to develop better prevention and therapeutic approaches, including better growth inhibitors and growth inhibitor combinations that can be used in foods. Current research focuses specifically on developing on improved understanding of regulatory networks and stress response systems in Listeria monocytogenes and to translating this knowledge into improved control strategies and therapeutics.

Relevant Key Publications:

  1. Oliver, H. F., R. H. Orsi, M. Wiedmann, and K. J. Boor. 2010. Listeria monocytogenes sB has a small core regulon and a conserved role in virulence, but differential contributions to stress tolerance, across a diverse collection of strains. Appl. Environ. Micro. 76:4216-4232.
  2. Oliver, H. F., R. H. Orsi, L. Ponnala, U. Keich, W. Wang, Q. Sun, S. W. Cartinhour, M. J. Filiatrault, M. Wiedmann, and K. J. Boor. 2009. Deep RNA sequencing of L. monocytogenes reveals overlapping and extensive stationary phase and sigma B-dependent transcriptomes, including multiple highly transcribed noncoding RNAs. BMC Genomics 10(1):641
  3. Ivy, R. A., Chan, Y. C., Bowen, B. M., Boor, K. J., and Wiedmann, M. 2010. Growth temperature-dependent contributions of response regulators, sB, PrfA, and motility factors to Listeria monocytogenes invasion of Caco-2 cells. Foodborne Pathog Dis. 7: 1337-1349
  4. Chaturongakul, S., S. Raengpradub, M. E. Palmer, T. M. Bergholz, R. H. Orsi, Y. Hu, J. Ollinger, M. Wiedmann, and K. J. Boor. 2010. Transcriptomic and phenotypic analyses identify coregulated, overlapping regulons among PrfA, CtsR, HrcA and the alternative sigma factors σB, σC, σH, and σL in Listeria monocytogenes.  Appl. Environ. Micro. 77:187-200
  5. Nielsen, J.S., M. Halberg Larsen; E. M. Sternkopf Lillebæk, T. M. Bergholz; M. H. G. Christiansen, K. J. Boor, M. Wiedmann, and B. H. Kallipolitis. 2011. A small RNA controls expression of the chitinase ChiA in Listeria monocytogenes.  PLoS ONE 6:e19019
  6. Stasiewicz, M. J., M. Wiedmann, and T. M. Bergholz. 2011. The transcriptional response of Listeria monocytogenes during adaptation to lactate and diacetate includes synergistic changes that increase fermentative acetoin production. Appl. Environ. Microbiol. 77: 5294-5306
  7. Stasiewicz, M. J., M. Wiedmann, and T. M. Bergholz. 2011. The transcriptional response of Listeria monocytogenes during adaptation to lactate and diacetate includes synergistic changes that increase fermentative acetoin production. Appl. Environ. Microbiol. 77: 5294-5306.
  8. Palmer, M. E., S. Chaturongakul, M. Wiedmann, and K. J. Boor. 2011. The Listeria monocytogenes sB Regulon and its Virulence-Associated Functions are Inhibited by a Small Molecule. mBio 2(6). pii: e00241-11
  9. Bergholz, T., B. Bowen, M. Wiedmann, and K. Boor. 2012. Listeria monocytogenes shows temperature dependent and independent responses to salt stress, including responses that induce cross-protection to other stresses. Appl. Environ. Micro. 78: 2602-2612.
  10. Ivy, R., M. Wiedmann, and K. J. Boor. 2012. Listeria monocytogenes grown at 7°C shows Reduced Acid Survival and an Altered Transcriptional Response to Acid Shock Compared to L. monocytogenes grown at 37°C. Appl. Environ. Micro. 78:3824-3836.
  11. Ringus, D. L., A. Gaballa, J. D. Helmann, M. Wiedmann, and K. J. Boor. 2013. Fluoro-phenyl-styrene-sulfonamide, a novel inhibitor of σB, activity, prevents the activation of σB, by environmental and energy stresses in Bacillus subtilis. Journal of Bacteriology: 195: 2509-2517.
  12. Tang, S., M. J. Stasiewicz, M. Wiedmann, K. J. Boor, and T. M. Bergholz. 2013. Efficacy of different antimicrobials on inhibition of Listeria monocytogenes growth in laboratory medium and on cold-smoked salmon. Int. J. Food Microbiol. 165:265-275
  13. Bergholz, T., S. Tang, M. Wiedmann, and K. J. Boor. 2013. Nisin resistance of Listeria monocytogenes is increased by exposure to salt Stress and is mediated via LiaR. Appl. Environ. Micro. 79:5682-5688.
  14. Denes, T. and M. Wiedmann. 2014. Environmental responses and phage susceptibility in foodborne pathogens: Implications for Improving Applications in Food Safety. Current Opinion in Biotechnology 26: 45–49.
  15. Guldimann, C., K. J. Boor, M. Wiedmann, and V. Guariglia-Oropeza. 2015. Resilience in the face of uncertainty: sigma B fine-tunes gene expression to support homeostasis in Gram-positive bacteria. Appl. Environ. Micro (accepted 05/15/2016; AEM00714-16R1).
  16. Tang, S. R. Orsi, H. den Bakker, M. Wiedmann, K. Boor, and T. Bergholz. 2015. Transcriptomic analysis of Listeria monocytogenes Adaptation to Growth on Vacuum-Packed Cold Smoked Salmon. Appl. Environ. Micro. 81:6812-6824.
  17. Orsi, R. H., T. M. Bergholz, M. Wiedmann and K. J Boor. 2015. The Listeria monocytogenes strain 10403S BioCyc database. Database (Oxford) Vol. 2015: Mar 28; 2015. pii: bav027. doi: 10.1093/database/bav027.
  18. Liu, Y., R. H. Orsi; K. J. Boor, M. Wiedmann, and V. Guariglia-Oropeza. 2016. An advanced Bioinformatics Approach for Analyzing RNAseq Data Reveals Sigma H-dependent Regulation of Competence Genes in Listeria monocytogenes. BMC Genomics 17:115.