Stress response of the thioredoxin Lmo1609 from Listeria monocytogenes

Abstract:

[Objective] The thioredoxin family plays an important role in the response of the foodborne bacterial pathogen Listeria monocytogenes to the oxidative stress during the adaptation to environment.Here,we explored the biological characteristics of the thioredoxin Lmo1609 in the oxidative stress tolerance and infection of L.monocytogenes.[Methods] We constructed the lmo1609-deleted and-complemented strains and then studied the growth,motility,oxidative stress tolerance,and pathogenicity of the strains both in vitro and in vivo.Moreover,we purified the recombinant Lmo1609 protein and then studied the oxidoreductase activity of the protein in vitro.[Results] The deletion of lmo1609 did not affect the bacterial growth but significantly reduced the swimming motility in vitro.Surprisingly,it enhanced the tolerance of this bacterium to H₂O₂ stress while showing no impact on bacterial infection.[Conclusion]This study indicates that the thioredoxin family member Lmo609 exhibiting the oxidoreductase activity contributes to the motility and oxidative stress tolerance but not in vivo infection of L.monocytogenes.