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Subcutaneous Infection of Methicillin Resistant Staphylococcus Aureus (MRSA)
Published on: February 10, 2011
Experimental hematogenous osteomyelitis by Staphylococcus aureus
K Matsushita1, M Hamabe, M Matsuoka
1Department of Orthopedic Surgery, St. Marianna University School of Medicine, Kawasaki, Kanagawa, Japan.
Abstract:
To assess bone marrow lodgement of bacteria that produce osteomyelitis, 10(6) colony forming units of 16 nonhemolytic strains of Staphylococcus aureus was injected intravenously into mice. Eleven of 16 strains showed bone marrow lodgement without the death of mice. The M-138 strain induced osteomyelitis in 100% of the mice. Furthermore, the difference of compact colony forming active substance activity between bone marrow lodgement and nonlodgement strains was statistically significant. Compact colony forming active substance, which is an alkali stable polysaccharide located on the cell surface of Staphylococcus aureus strain, caused compact formation of the strains in serum soft agar or fibrinogen soft agar, and it clotted animal plasma. These results suggest that bacterial factors are important for bacterial lodgement at the onset of staphylococcal hematogenous osteomyelitis.
Insights
Bacterial factors, specifically a cell surface polysaccharide, are crucial for Staphylococcus aureus lodgement in bone marrow, initiating hematogenous osteomyelitis. This finding is key to understanding staphylococcal bone infections.
Area of Science:
- Microbiology
- Immunology
- Pathology
Background:
- Osteomyelitis is a bone infection often caused by Staphylococcus aureus.
- Understanding the initial bacterial mechanisms for bone marrow lodgement is critical for preventing staphylococcal hematogenous osteomyelitis.
Purpose of the Study:
- To investigate bacterial factors contributing to bone marrow lodgement by Staphylococcus aureus.
- To identify specific bacterial components involved in the early stages of staphylococcal osteomyelitis.
Main Methods:
- Intravenous injection of 10(6) colony forming units of 16 nonhemolytic Staphylococcus aureus strains into mice.
- Observation of bone marrow lodgement and osteomyelitis development.
- Assay of compact colony forming active substance (CCFAS) activity in lodgement and non-lodgement strains.
Main Results:
- Eleven of 16 Staphylococcus aureus strains demonstrated bone marrow lodgement without causing mortality.
- The M-138 strain induced osteomyelitis in 100% of the mice.
- A statistically significant difference in CCFAS activity was observed between bone marrow lodgement and non-lodgement strains.
Conclusions:
- Bacterial factors, particularly the cell surface polysaccharide CCFAS, play a significant role in bacterial lodgement during the onset of staphylococcal hematogenous osteomyelitis.
- CCFAS activity correlates with the ability of Staphylococcus aureus to establish in bone marrow.
- Further research into CCFAS may offer therapeutic targets for preventing staphylococcal osteomyelitis.

