Skip to main page content
Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2013 Sep 4;8(9):e73603.
doi: 10.1371/journal.pone.0073603. eCollection 2013.

Characterisation of the Transcriptomes of Genetically Diverse Listeria Monocytogenes Exposed to Hyperosmotic and Low Temperature Conditions Reveal Global Stress-Adaptation Mechanisms

Affiliations
Free PMC article

Characterisation of the Transcriptomes of Genetically Diverse Listeria Monocytogenes Exposed to Hyperosmotic and Low Temperature Conditions Reveal Global Stress-Adaptation Mechanisms

Juliana Durack et al. PLoS One. .
Free PMC article

Abstract

The ability of Listeria monocytogenes to adapt to various food and food- processing environments has been attributed to its robustness, persistence and prevalence in the food supply chain. To improve the present understanding of molecular mechanisms involved in hyperosmotic and low-temperature stress adaptation of L. monocytogenes, we undertook transcriptomics analysis on three strains adapted to sub-lethal levels of these stress stimuli and assessed functional gene response. Adaptation to hyperosmotic and cold-temperature stress has revealed many parallels in terms of gene expression profiles in strains possessing different levels of stress tolerance. Gene sets associated with ribosomes and translation, transcription, cell division as well as fatty acid biosynthesis and peptide transport showed activation in cells adapted to either cold or hyperosmotic stress. Repression of genes associated with carbohydrate metabolism and transport as well as flagella was evident in stressed cells, likely linked to activation of CodY regulon and consequential cellular energy conservation.

Conflict of interest statement

Competing Interests: The authors have declared that no competing interests exist.

Figures

Figure 1
Figure 1. Histogram showing distribution of a mean generation time within bootstrap replicates based on the origin of isolate of Listeria monocytogenes strains exposed to either a.) 12.5% NaCl or b.) cold 4°C temperature in BHIB.
Figure 2
Figure 2. Heat map showing statistical trends for up-regulated functionally defined sets of genes in strains of L. monocytogenes exposed to either sub-lethal level of NaCl or cold stresses.
T-test based procedure was used to score the changes in expression of each functional gene set, statistically significant T-values (as determined by a two-tailed P-value) are expressed from -5 (shown in green) to 5 (shown in red). Gene sets were considered significantly up-regulated with T-value ≥ 1 and significantly down-regulated with T-value ≤ -1.
Figure 3
Figure 3. Heat map showing statistical trends for down-regulated functionally defined sets of genes in strains of L. monocytogenes exposed to either sub-lethal level of NaCl or cold stresses.
T-test based procedure was used to score the changes in expression of each functional gene set, statistically significant T-values (as determined by a two-tailed P-value) are expressed from -5 (shown in green) to 5 (shown in red). Gene sets were considered significantly up-regulated with T-value ≥ 1 and significantly down-regulated with T-value ≤ -1.
Figure 4
Figure 4. Swarming abilities of three strains of L. monocytogenes expressed as average motility zone diameters (mm).
Swarming motility was assessed on semisoft BHIA plates supplemented with NaCl ranging from 0% to 8% w/v either a) at 25°C or b) at 4°C.
Figure 5
Figure 5. Heat map showing statistical trends for regulons in strains of L. monocytogenes exposed to either sub-lethal level of NaCl or cold stresses.
T-test based procedure was used to score the changes in expression of each regulon, statistically significant T-values (as determined by a two-tailed P-value) are expressed from -5 (shown in green) to 5 (shown in red). Gene sets were considered significantly up-regulated with T-value ≥ 1 and significantly down-regulated with T-value ≤ -1.

Similar articles

See all similar articles

Cited by 16 articles

See all "Cited by" articles

References

    1. Farber JM, Coates F, Daley E (1992) Minimum water activity requirements of the growth of Listeria monocytogenes . Lett Appl Microbiol 15: 103-105. doi:10.1111/j.1472-765X.1992.tb00737.x. - DOI
    1. Liu D, Lawrence ML, Ainsworth AJ, Austin FW (2005) Comparative assessment of acid, alkali and salt tolerance in Listeria monocytogenes virulent and avirulent strains. FEMS Microbiol Lett 243: 373-378. doi:10.1016/j.femsle.2004.12.025. PubMed: 15686837. - DOI - PubMed
    1. Shabala L, Lee SH, Cannesson P, Ross T (2008) Acid and NaCl limits to growth of Listeria monocytogenes and influence of sequence of inimical acid and NaCl levels on inactivation kinetics. J Food Protect 71: 1169-1177. PubMed: 18592742. - PubMed
    1. Walker SJ, Archer P, Banks JG (1990) Growth of Listeria monocytogenes at refrigeration temperatures. J Appl Bacteriol 68: 157-162. doi:10.1111/j.1365-2672.1990.tb02561.x. PubMed: 2108109. - DOI - PubMed
    1. Begley M, Cormac GM, Hill C (2002) Bile stress response in Listeria monocytogenes LO28: adaptation, cross-protection, and identification of genetic loci involved in bile resistance. Appl Environ Microbiol 68: 6005-6012. doi:10.1128/AEM.68.12.6005-6012.2002. PubMed: 12450822. - DOI - PMC - PubMed

Publication types

MeSH terms

Grant support

National Food Innovation Strategy and the University of Tasmania provided the funding for this work. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
Feedback