title: Staphylococcus aureus transcriptomic response to inhibition by H2O2-producing Lactococcus garvieae.
abstract: Growth of the foodborne pathogen Staphylococcus aureus can be inhibited in milk and in cheese by the hydrogen peroxide-producing Lactococcus garvieae N201 dairy strain. Transcriptomic responses of two S. aureus strains, the S. aureus SA15 dairy strain and the MW2 human pathogenic strain, to this growth inhibition were investigated in Brain-Heart Infusion broth under a high or a low aeration level. We demonstrated that S. aureus MW2 had a higher resistance to L. garvieae inhibition under the high aeration level: this correlated to a higher survival under hydrogen peroxide exposure. Conversely, the two strains were similarly inhibited under the low aeration level. Expression of S. aureus genes involved in response to H2O2 or other stresses as well as in cell division was generally repressed by L. garvieae. However, differential expressions between the two S. aureus strains were observed, especially under the high aeration level. Additionally, expression of virulence-related genes (enterotoxins, regulatory genes) was modulated by L. garvieae depending on the aeration level and on the S. aureus strain. This study led to new insights into potential molecular mechanisms of S. aureus inhibition by Lactic Acid Bacteria via H2O2 production.
authors.affiliation: INRA, UR545, Unité de Recherches Fromagères, 20 côte de Reyne, 15000 Aurillac, France. Electronic address: pierre.delpech@clermont.inra.fr.
authors.forename: Pierre
authors.initials: P
authors.lastname: Delpech
authors.affiliation: Laboratoire de Biologie, IUT Génie Biologique, Université d'Auvergne, 100 rue de l'Egalité, 15013 Aurillac, France.
authors.forename: Stéphanie
authors.initials: S
authors.lastname: Bornes
authors.affiliation: INRA, UR545, Unité de Recherches Fromagères, 20 côte de Reyne, 15000 Aurillac, France.
authors.forename: Elina
authors.initials: E
authors.lastname: Alaterre
authors.affiliation: Laboratoire de Biologie, IUT Génie Biologique, Université d'Auvergne, 100 rue de l'Egalité, 15013 Aurillac, France.
authors.forename: Muriel
authors.initials: M
authors.lastname: Bonnet
authors.affiliation: Laboratoire de Biologie, IUT Génie Biologique, Université d'Auvergne, 100 rue de l'Egalité, 15013 Aurillac, France.
authors.forename: Geneviève
authors.initials: G
authors.lastname: Gagne
authors.affiliation: INRA, UR545, Unité de Recherches Fromagères, 20 côte de Reyne, 15000 Aurillac, France.
authors.forename: Marie-Christine
authors.initials: MC
authors.lastname: Montel
authors.affiliation: INRA, UR545, Unité de Recherches Fromagères, 20 côte de Reyne, 15000 Aurillac, France. Electronic address: celine.delbes@clermont.inra.fr.
authors.forename: Céline
authors.initials: C
authors.lastname: Delbès
mesh_terms: D000818:Animals; D000898:Antibiosis; D002611:Cheese / Q000382:microbiology; D004768:Enterotoxins / Q000235:genetics; D005516:Food Microbiology; D020869:Gene Expression Profiling; D006801:Humans; D006861:Hydrogen Peroxide / Q000378:metabolism*; D017045:Lactococcus / Q000378:metabolism*; D008892:Milk / Q000382:microbiology; D060888:Real-Time Polymerase Chain Reaction; D013211:Staphylococcus aureus / Q000235:genetics* / Q000472:pathogenicity / Q000502:physiology*; D013312:Stress, Physiological / Q000235:genetics
chemical_list: D004768:Enterotoxins; D006861:Hydrogen Peroxide
keywords: Cell division; Hydrogen peroxide; Lactococcus garvieae; RT-qPCR; Staphylococcus aureus; Stress response