Regulated gene expression in Staphylococcus aureus for identifying conditional lethal phenotypes and antibiotic mode of action

Gene. 2000 Sep 19;255(2):297-305. doi: 10.1016/s0378-1119(00)00325-5.


Selectively regulating gene expression in bacteria has provided an important tool for studying gene function. However, well-regulated gene control systems have been restricted primarily for use in laboratory non-pathogenic strains of bacteria (e.g. Escherichia coli, Bacillus subtilis). The development of analogous systems for use in bacterial pathogens such as Staphylococcus aureus would significantly enhance our ability to examine the contribution of any given gene product to pathogen growth and viability. In this report, we adapt, examine and compare three regulated gene expression systems in S. aureus, which had previously been used in B. subtilis. We demonstrate that all three systems function and exhibit titratable induction, together covering a dynamic range of gene expression of approximately 3000-fold. This dynamic range correlates well with the physiological expression levels of cellular proteins. Importantly, we show that one of these systems, the Spac system, is particularly useful for examining gene essentiality and creating specific conditional lethal phenotypes. Moreover, we find that titration of selective target gene products using this system allows direct demonstration of antibiotic mode of action.

Publication types

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

MeSH terms

  • Anti-Bacterial Agents / pharmacology*
  • Bacterial Proteins*
  • Cell Division / drug effects
  • Drug Resistance, Microbial / genetics
  • Gene Expression Regulation, Bacterial / drug effects
  • Gene Expression Regulation, Bacterial / genetics*
  • Genes, Essential / genetics
  • Genes, Lethal / genetics
  • Lac Operon / genetics
  • Membrane Proteins / genetics
  • Microbial Sensitivity Tests
  • Phenotype
  • Plasmids / genetics
  • Recombinant Fusion Proteins / genetics
  • Recombinant Fusion Proteins / metabolism
  • Staphylococcus aureus / drug effects
  • Staphylococcus aureus / genetics*
  • Staphylococcus aureus / growth & development
  • Tetracycline / pharmacology
  • Xylose / metabolism
  • beta-Galactosidase / genetics
  • beta-Galactosidase / metabolism


  • Anti-Bacterial Agents
  • Bacterial Proteins
  • Membrane Proteins
  • Recombinant Fusion Proteins
  • SpaC protein, bacteria
  • Xylose
  • beta-Galactosidase
  • Tetracycline