Regulation of Staphylococcus Aureus Capsular Polysaccharide Type 5: CO2 Inhibition in Vitro and in Vivo

J Infect Dis. 1997 Aug;176(2):431-8. doi: 10.1086/514061.


Staphylococcus aureus capsular polysaccharide type 5 (CP5) expression was investigated in lung tissue and nasal polyps of two cystic fibrosis (CF) patients, in rats, and in vitro using ELISA and IFA. In CF tissues, S. aureus expressed protein A and teichoic acid but only 1%-5% of cells expressed CP5. When rats were challenged with CP5-positive S. aureus in the granuloma pouch model, only 1%-5% of CP5-positive cells were detectable in pouch exudates. CF and pouch isolates, however, reexpressed CP5 (70%-90% of cells) when grown in vitro with air. Addition of > or = 1% CO2 to air or to O2/N2 gas mixtures reduced CP5 expression significantly (P < .001) in a dose-dependent manner (6%-1% CP5-positive cells). The results show that S. aureus does not produce CP5 in CF airways and in rat granuloma pouches and that CO2 is an environmental signal that regulates CP5 expression.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Bacterial Capsules*
  • Carbon Dioxide / metabolism*
  • Carbon Dioxide / pharmacology
  • Cystic Fibrosis / microbiology
  • Granuloma / microbiology
  • Hydrogen-Ion Concentration
  • Lung / metabolism
  • Lung / microbiology
  • Male
  • Nasal Polyps / microbiology
  • Polysaccharides, Bacterial / biosynthesis*
  • Rats
  • Rats, Wistar
  • Staphylococcal Infections / metabolism*
  • Staphylococcal Infections / microbiology
  • Staphylococcal Protein A / biosynthesis
  • Staphylococcus aureus / drug effects
  • Staphylococcus aureus / growth & development
  • Staphylococcus aureus / metabolism*
  • Teichoic Acids / biosynthesis


  • Polysaccharides, Bacterial
  • Staphylococcal Protein A
  • Teichoic Acids
  • capsular polysaccharide, type 5, Staphylococcus aureus
  • Carbon Dioxide