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: 2.81). 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.

494 Reads
  • Source
    • "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. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Traumatology and orthopedic surgery can benefit from the use of efficient local antibiotic-eluting systems to avoid bacterial contamination of implanted materials. In this work a new percutaneous porous-wall hollow implant was successfully used as a local antibiotic-eluting device both in vitro and in vivo. The implant is a macroporous 316L stainless steel filter tube with a nominal filtration cut-off size of 200nm with one open end which was used to load the synthetic antibiotic linezolid and an opposite blind end. The antibiotic release kinetics from the device on a simulated biological fluid under in vitro conditions demonstrated an increased concentration during the first five days that subsequently was sustained for at least seven days, showing a kinetic close to a zero order release. Antibiotic-loaded implants were placed in the tibia of four sheep which were trans-surgically experimentally infected with a biofilm forming strain of Staphylococcus aureus. After 7 and 9 days post infection, sheep did not show any evidence of infection as demonstrated by clinical, pathological and microbiological findings. These results demonstrate the capability of such an antibiotic-loaded implant to prevent infection in orthopedic devices in vivo. Further research is needed to assess its possible use in traumatology and orthopedic surgery.
    International Journal of Pharmaceutics 05/2013; 452(1). DOI:10.1016/j.ijpharm.2013.04.076 · 3.65 Impact Factor
  • Source
    • "For bacterial enumeration, the mice were euthanized using isoflurane followed by cervical dislocation, and the nasal tissue was homogenized and vortexed for 5 min in PBS, and the homogenate was plated on THA with or without streptomycin after appropriate serial dilutions. Bacterial identification was based on antibiotic resistance patterns, colony morphology, and color as previously described [10]. Briefly, we have shown that mice (n = 5) administered PBS alone in the nose, harbor on average 1.9×106 CFU per nose, but none of the endogenous bacteria grew on streptomycin (500 µg/ml) plates (Figure S1). "
    [Show abstract] [Hide abstract]
    ABSTRACT: Methicillin-resistant S. aureus emerged in recent decades to become a leading cause of infection worldwide. Colonization with MRSA predisposes to infection and facilitates transmission of the pathogen; however, available regimens are ineffective at preventing MRSA colonization. Studies of human nasal flora suggest that resident bacteria play a critical role in limiting S. aureus growth, and prompted us to query whether application of commensal resident bacteria could prevent nasal colonization with MRSA. We established a murine model system to study this question, and showed that mice nasally pre-colonized with S. epidermidis became more resistant to colonization with MRSA. Our study suggests that application of commensal bacteria with antibiotics could represent a more effective strategy to prevent MRSA colonization.
    PLoS ONE 10/2011; 6(10):e25880. DOI:10.1371/journal.pone.0025880 · 3.23 Impact Factor
  • Source
    • "Similar observations have been made for Dutch children aged 1–19 years, for Israeli children aged 40 months or younger, and for South African children aged 1–60 months [10, 16, 17]. It has been suggested that bacterial interference orchestrated by the host immune system might explain the inverse relation between S. aureus and S. pneumoniae [42, 43]. Our results demonstrate, for the first time, the negative association between these bacterial pathogens in the same niche, i.e., the nasal cavity. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Streptococcus pneumoniae and Staphylococcus aureus cause significant morbidity and mortality worldwide. We investigated both the colonization and co-colonization characteristics for these pathogens among 250 healthy children from 2 to 5 years of age in Merida, Venezuela, in 2007. The prevalence of S. pneumoniae colonization, S. aureus colonization, and S. pneumoniae-S. aureus co-colonization was 28%, 56%, and 16%, respectively. Pneumococcal serotypes 6B (14%), 19F (12%), 23F (12%), 15 (9%), 6A (8%), 11 (8%), 23A (6%), and 34 (6%) were the most prevalent. Non-respiratory atopy was a risk factor for S. aureus colonization (p = 0.017). Vaccine serotypes were negatively associated with preceding respiratory infection (p = 0.02) and with S. aureus colonization (p = 0.03). We observed a high prevalence of pneumococcal resistance against trimethoprim-sulfamethoxazole (40%), erythromycin (38%), and penicillin (14%). Semi-quantitative measurement of pneumococcal colonization density showed that children with young siblings and low socioeconomic status were more densely colonized (p = 0.02 and p = 0.02, respectively). In contrast, trimethoprim-sulfamethoxazole- and multidrug-resistant-pneumococci colonized children sparsely (p = 0.03 and p = 0.01, respectively). Our data form an important basis to monitor the future impact of pneumococcal vaccination on bacterial colonization, as well as to recommend a rationalized and restrictive antimicrobial use in our community.
    European Journal of Clinical Microbiology 01/2011; 30(1):7-19. DOI:10.1007/s10096-010-1044-6 · 2.67 Impact Factor
Show more


494 Reads
Available from