Role of Staphylococcus aureus catalase in niche competition against Streptococcus pneumoniae

Division of Pediatric Infectious Diseases and Immunobiology Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA.
Journal of bacteriology (Impact Factor: 2.69). 05/2008; 190(7):2275-8. DOI: 10.1128/JB.00006-08
Source: PubMed

ABSTRACT Nasal colonization by Staphylococcus aureus is a major predisposing factor for subsequent infection. Recent reports of increased S. aureus colonization among children receiving pneumococcal vaccine implicate Streptococcus pneumoniae as an important competitor for the same niche. Since S. pneumoniae uses H2O2 to kill competing bacteria, we hypothesized that oxidant defense could play a significant role in promoting S. aureus colonization of the nasal mucosa. Using targeted mutagenesis, we showed that S. aureus expression of catalase contributes significantly to the survival of this pathogen in the presence of S. pneumoniae both in vitro and in a murine model of nasal cocolonization.

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    • "Bacterial competition using inhibitory growth factors is not uncommon. For instance, in humans hydrogen peroxide produced by Streptococcus pneumoniae inhibits the growth of other respiratory tract microorganisms such as Haemophilus influenzae, Neisseria meningitidis, Moraxella catarrhalis and S. aureus (Park et al., 2008). Another possible explanation could be the local depletion of a vital factor necessary for growth after an intense proliferation of the experimental strain of S. aureus, favoring other microorganisms with different metabolic necessities to proliferate and replace the original strain. "
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