title: Growth of Yersinia pseudotuberculosis in human plasma: impacts on virulence and metabolic gene expression.
abstract: BACKGROUND
  In man, infection by the Gram-negative enteropathogen Yersinia pseudotuberculosis is usually limited to the terminal ileum. However, in immunocompromised patients, the microorganism may disseminate from the digestive tract and thus cause a systemic infection with septicemia.
  
  
  RESULTS
  To gain insight into the metabolic pathways and virulence factors expressed by the bacterium at the blood stage of pseudotuberculosis, we compared the overall gene transcription patterns (the transcriptome) of bacterial cells cultured in either human plasma or Luria-Bertani medium. The most marked plasma-triggered metabolic consequence in Y. pseudotuberculosis was the switch to high glucose consumption, which is reminiscent of the acetogenic pathway (known as "glucose overflow") in Escherichia coli. However, upregulation of the glyoxylate shunt enzymes suggests that (in contrast to E. coli) acetate may be further metabolized in Y. pseudotuberculosis. Our data also indicate that the bloodstream environment can regulate major virulence genes (positively or negatively); the yadA adhesin gene and most of the transcriptional units of the pYV-encoded type III secretion apparatus were found to be upregulated, whereas transcription of the pH6 antigen locus was strongly repressed.
  
  
  CONCLUSIONS
  Our results suggest that plasma growth of Y. pseudotuberculosis is responsible for major transcriptional regulatory events and prompts key metabolic reorientations within the bacterium, which may in turn have an impact on virulence.
authors.affiliation: Inserm U801, Lille, F-59019, Université Lille II, Faculté de Médecine Henri Warembourg), Lille, France. mlrosso@pasteur.fr
authors.forename: Marie-Laure
authors.initials: ML
authors.lastname: Rosso
authors.forename: Sylvie
authors.initials: S
authors.lastname: Chauvaux
authors.forename: Rodrigue
authors.initials: R
authors.lastname: Dessein
authors.forename: Caroline
authors.initials: C
authors.lastname: Laurans
authors.forename: Lionel
authors.initials: L
authors.lastname: Frangeul
authors.forename: Céline
authors.initials: C
authors.lastname: Lacroix
authors.forename: Angèle
authors.initials: A
authors.lastname: Schiavo
authors.forename: Marie-Agnès
authors.initials: MA
authors.lastname: Dillies
authors.forename: Jeannine
authors.initials: J
authors.lastname: Foulon
authors.forename: Jean-Yves
authors.initials: JY
authors.lastname: Coppée
authors.forename: Claudine
authors.initials: C
authors.lastname: Médigue
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Carniel
authors.forename: Michel
authors.initials: M
authors.lastname: Simonet
authors.forename: Michaël
authors.initials: M
authors.lastname: Marceau
mesh_terms: D018829:Adhesins, Bacterial / Q000235:genetics / Q000378:metabolism; D002952:Citric Acid Cycle / Q000235:genetics; D003470:Culture Media; D020869:Gene Expression Profiling; D015964:Gene Expression Regulation, Bacterial; D005947:Glucose / Q000378:metabolism; D006019:Glycolysis / Q000235:genetics; D006801:Humans; D007501:Iron / Q000378:metabolism; D010949:Plasma / Q000382:microbiology*; D015854:Up-Regulation; D014774:Virulence; D015011:Yersinia pseudotuberculosis / Q000235:genetics* / Q000254:growth & development / Q000472:pathogenicity*; D015012:Yersinia pseudotuberculosis Infections / Q000378:metabolism / Q000382:microbiology
chemical_list: D018829:Adhesins, Bacterial; D003470:Culture Media; C064832:YadA protein, Yersinia; D007501:Iron; D005947:Glucose