Inorganic polyphosphate is essential for long-term survival and virulence factors in Shigella and Salmonella spp

Proc Natl Acad Sci U S A. 2002 May 28;99(11):7675-80. doi: 10.1073/pnas.112210499.


The importance of inorganic polyphosphate (poly P) and poly P kinase (PPK), the enzyme principally responsible for its synthesis, has been established previously for stationary-phase survival of Escherichia coli and virulence in Pseudomonas aeruginosa. The gene (ppk) that encodes PPK is highly conserved among many bacterial pathogens, including Shigella and Salmonella spp. In view of the phylogenetic similarity of the enteropathogens and the frequency with which virulence factors are expressed in stationary phase, the ppk gene of pathogenic Shigella flexneri, Salmonella enterica serovar Dublin, and Salmonella enterica serovar typhimurium have been cloned and deleted. In some of these mutants lacking ppk, the phenotypes included features indicative of decreased virulence such as: (i) growth defects, (ii) defective responses to stress and starvation, (iii) loss of viability, (iv) polymyxin sensitivity, (v) intolerance to acid and heat, and (vi) diminished invasiveness in epithelial cells. Thus PPK may prove, as it has with P. aeruginosa, to be an attractive target for antibiotics, with low toxicity because PPK is not found in higher eukaryotes.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Aerobiosis
  • Conserved Sequence
  • Culture Media
  • Doxorubicin / pharmacology
  • Escherichia coli / pathogenicity
  • Kinetics
  • Molecular Sequence Data
  • Phosphotransferases (Phosphate Group Acceptor) / genetics
  • Phosphotransferases (Phosphate Group Acceptor) / metabolism
  • Polymyxin B / pharmacology
  • Polyphosphates / pharmacology*
  • Pseudomonas aeruginosa / pathogenicity
  • Salmonella / drug effects*
  • Salmonella / growth & development
  • Salmonella / pathogenicity
  • Salmonella typhimurium / drug effects
  • Salmonella typhimurium / growth & development
  • Shigella / drug effects*
  • Shigella / growth & development
  • Shigella / pathogenicity
  • Virulence / drug effects


  • Culture Media
  • Polyphosphates
  • Doxorubicin
  • Phosphotransferases (Phosphate Group Acceptor)
  • polyphosphate kinase
  • Polymyxin B

Associated data

  • GENBANK/AF085682