TABLE 3

Selected upregulated stress response genes in Escherichia coli O157:H7 adapted to a sublethal level of thymol, carvacrol, or trans-cinnamaldehyde compared to nonadapted cellsa

Gene identifierFold changebGene product description
1/2T1/2C1/2TC
Cell envelope
    ECs1884492.1416.9cPhage shock protein, PspD
    ECs1883528.5434.0PspC family transcriptional regulator
    pspB615.4465.0Phage shock protein, PspB
    ECs1881763.2634.3Phage shock protein, PspA
    pspG1459.21452.2Phage shock protein, PspG
    cpxP566.9374.6Cell envelope toxicity response protein, CpxP
Heat resistance
    ECs10508.49.8Heat shock protein, HspQ
    ECs43108.56.0RNA polymerase factor sigma-32
    ECs462622.225.2Heat shock chaperone, IbpB
    ECs462712.013.8Heat shock protein, IbpA
    ECs016513.88.5Serine endoprotease, degrade damaged proteins
    ECs253915.47.5Heat shock protein, HtpX
Acid resistance
    ECs511314.4Lysine decarboxylase 1, CadA
    cadB16.1Lysine/cadaverine antiporter, CadB
    ECs230337.442.6Acid-shock protein, resistance against moderate acid
Oxidative stress resistance
    grxA9.38.8Glutaredoxin, GrxA
    ECs483410.5Superoxide dismutase, SodA
    ECs504510.49.0Redox-sensitive transcriptional activator, SoxR
    ECs504417.117.1DNA-binding transcriptional regulator, SoxS
    ECs248717.69.7Methionine sulfoxide reductase B
    ECs344822.97.28.9Thioredoxin 2, TrxC
    ECs327128.98.510.1Manganese transport protein, MntH
    ECs09316.06.2Nitroreductase A
Iron transport
    ECs06359.82,3-Dihydro-2,3-dihydroxybenzoate dehydrogenase
    entF7.95.5Enterobactin synthase subunit F, EntF
    ECs06308.8Enterobactin exporter, EntS
    ECs063411.35.82,3-Dihydro-2,3-dihydroxybenzoate synthetase, EntB
    entE17.79.02,3-Dihydroxybenzoate-AMP ligase, EntE
    ECs063223.810.37.9Isochorismate synthase, EntC
    ECs06275.65.35.3Iron-enterobactin transporter ATP-binding protein
    ECs06288.85.8Iron-enterobactin transporter permease
    ECs062912.610.19.4Iron-enterobactin transporter membrane protein
    ECs063111.17.36.8Iron-enterobactin transporter periplasmic binding protein
    ECs13605.8Bifunctional enterobactin receptor/adhesin, Iha
    ECs062417.814.36.0Enterobactin/ferric enterobactin esterase, Fes
    ECs43805.0Heme utilization/transport protein, ChuA
    ECs438216.09.77.3Hemin binding protein, ShuT
    hemH9.47.4Ferrochelatase, HemH
    ECs39175.8Ferrichrome iron receptor
    ECs01547.26.98.3Ferrichrome outer membrane transporter
    ECs14807.3Outer membrane receptor for Fe3+ uptake, FhuE
    ECs532710.110.35.0Ferrioxamine B reductase, FhuF
    ECs389011.28.25.2Biopolymer transport protein, ExbB
    ECs38895.7Biopolymer transport protein, ExbD
    feoA6.313.55.1Ferrous iron transport protein A, FeoA
    feoB5.37.7Ferrous iron transport protein B, FeoB
    ECs39165.36.2Iron-siderophore iron ABC transporter ATP-binding protein
    ECs20555.2Outer membrane receptor for iron transport
    ECs55318.810.3Bacterioferritin-associated ferredoxin, Bfd
  • a Cutoff criteria for upregulation were Padj of <0.05 and fold change ≥5.

  • b 1/2T, 0.16 mg/ml thymol; 1/2C, 0.16 mg/ml carvacrol; 1/2TC, 0.16 mg/ml trans-cinnamaldehyde.

  • c —, no detection of differentially expressed gene at the set criteria.