title: Universal stress proteins are important for oxidative and acid stress resistance and growth of Listeria monocytogenes EGD-e in vitro and in vivo.
abstract: BACKGROUND
  Pathogenic bacteria maintain a multifaceted apparatus to resist damage caused by external stimuli. As part of this, the universal stress protein A (UspA) and its homologues, initially discovered in Escherichia coli K-12 were shown to possess an important role in stress resistance and growth in several bacterial species.
  
  
  RESULTS
  We conducted a study to assess the role of three homologous proteins containing the UspA domain in the facultative intracellular human pathogen Listeria monocytogenes under different stress conditions. The growth properties of three UspA deletion mutants (Δlmo0515, Δlmo1580 and Δlmo2673) were examined either following challenge with a sublethal concentration of hydrogen peroxide or under acidic conditions. We also examined their ability for intracellular survival within murine macrophages. Virulence and growth of usp mutants were further characterized in invertebrate and vertebrate infection models. Tolerance to acidic stress was clearly reduced in Δlmo1580 and Δlmo0515, while oxidative stress dramatically diminished growth in all mutants. Survival within macrophages was significantly decreased in Δlmo1580 and Δlmo2673 as compared to the wild-type strain. Viability of infected Galleria mellonella larvae was markedly higher when injected with Δlmo1580 or Δlmo2673 as compared to wild-type strain inoculation, indicating impaired virulence of bacteria lacking these usp genes. Finally, we observed severely restricted growth of all chromosomal deletion mutants in mice livers and spleens as compared to the load of wild-type bacteria following infection.
  
  
  CONCLUSIONS
  This work provides distinct evidence that universal stress proteins are strongly involved in listerial stress response and survival under both in vitro and in vivo growth conditions.
authors: Institute of Medical Microbiology, Justus-Liebig-University, Giessen, Germany.
authors: Christa
authors: C
authors: Seifart Gomes
authors: Benjamin
authors: B
authors: Izar
authors: Farhad
authors: F
authors: Pazan
authors: Walid
authors: W
authors: Mohamed
authors: Mobarak Abu
authors: MA
authors: Mraheil
authors: Krishnendu
authors: K
authors: Mukherjee
authors: André
authors: A
authors: Billion
authors: Yair
authors: Y
authors: Aharonowitz
authors: Trinad
authors: T
authors: Chakraborty
authors: Torsten
authors: T
authors: Hain
mesh_terms: D000143:Acids / Q000737:chemistry; D000818:Animals; D001426:Bacterial Proteins / Q000378:metabolism*; D002460:Cell Line; D017931:DNA Primers / Q000737:chemistry; D005260:Female; D005786:Gene Expression Regulation; D015964:Gene Expression Regulation, Bacterial; D006360:Heat-Shock Proteins / Q000378:metabolism*; D006801:Humans; D006861:Hydrogen Peroxide / Q000737:chemistry; D007313:Insecta; D008089:Listeria monocytogenes / Q000378:metabolism*; D008264:Macrophages / Q000166:cytology / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D008954:Models, Biological; D009154:Mutation; D018384:Oxidative Stress; D016133:Polymerase Chain Reaction / Q000379:methods; D060888:Real-Time Polymerase Chain Reaction / Q000379:methods
chemical_list: D000143:Acids; D001426:Bacterial Proteins; D017931:DNA Primers; D006360:Heat-Shock Proteins; C078564:universal stress protein A, Bacteria; D006861:Hydrogen Peroxide