title: Screening of the two-component-system histidine kinases of Listeria monocytogenes EGD-e. LiaS is needed for growth under heat, acid, alkali, osmotic, ethanol and oxidative stresses.
abstract: To study the role of each two-component system (TCS) histidine kinase (HK) in stress tolerance of Listeria monocytogenes EGD-e, we monitored the growth of individual HK deletion mutant strains under heat (42.5 °C), acid (pH 5.6), alkali (pH 9.4), osmotic (6% NaCl), ethanol (3.5 vol%), and oxidative (5 mM H2O2) stresses. The growth of ΔliaS (Δlmo1021) strain was impaired under each stress, with the most notable decrease under heat and osmotic stresses. The ΔvirS (Δlmo1741) strain showed nearly completely restricted growth at high temperature and impaired growth in ethanol. The growth of ΔagrC (Δlmo0050) strain was impaired under osmotic stress and slightly under oxidative stress. We successfully complemented the HK mutations using a novel allelic exchange based approach. This approach avoided the copy-number problems associated with in trans complementation from a plasmid. The mutant phenotypes were restored to the wild-type level in the complemented strains. This study reveals novel knowledge on the HKs needed for growth of L. monocytogenes EGD-e under abovementioned stress conditions, with LiaS playing multiple roles in stress tolerance of L. monocytogenes EGD-e.
authors.affiliation: Department of Food Hygiene and Environmental Health, Faculty of Veterinary Medicine, University of Helsinki, P.O. Box 66, 00014, Helsinki University, Helsinki, Finland. Electronic address: anna.pontinen@helsinki.fi.
authors.forename: Anna
authors.initials: A
authors.lastname: Pöntinen
authors.affiliation: Department of Food Hygiene and Environmental Health, Faculty of Veterinary Medicine, University of Helsinki, P.O. Box 66, 00014, Helsinki University, Helsinki, Finland. Electronic address: miia.lindstrom@helsinki.fi.
authors.forename: Miia
authors.initials: M
authors.lastname: Lindström
authors.affiliation: Department of Bacteriology and Immunology, Medicum, and Research Programs Unit, Immunobiology, University of Helsinki, P.O. Box 21, 00014, Helsinki University, Finland; Division of Clinical Microbiology, Helsinki University Hospital, HUSLAB, Helsinki, Finland. Electronic address: mikael.skurnik@helsinki.fi.
authors.forename: Mikael
authors.initials: M
authors.lastname: Skurnik
authors.affiliation: Department of Food Hygiene and Environmental Health, Faculty of Veterinary Medicine, University of Helsinki, P.O. Box 66, 00014, Helsinki University, Helsinki, Finland. Electronic address: hannu.korkeala@helsinki.fi.
authors.forename: Hannu
authors.initials: H
authors.lastname: Korkeala
mesh_terms: D000222:Adaptation, Physiological / Q000235:genetics; D000468:Alkalies / Q000378:metabolism*; D000431:Ethanol / Q000378:metabolism*; D018628:Gene Dosage; D005816:Genetic Complementation Test; D000071677:Histidine Kinase / Q000378:metabolism*; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D008089:Listeria monocytogenes / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism; D009154:Mutation; D018384:Oxidative Stress; D010641:Phenotype; D011494:Protein Kinases / Q000378:metabolism; D017384:Sequence Deletion
chemical_list: D000468:Alkalies; D000431:Ethanol; D011494:Protein Kinases; D000071677:Histidine Kinase
keywords: Histidine kinase; Listeria monocytogenes; Stress response; Two-component system