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Increased resistance of bacteria after adherence to polymethyl methacrylate. An in vitro study
1Department of Orthopedics, Faculty of Medicine, Kyushu University, Fukuoka, Japan.
Abstract:
The pathobiology of total joint prosthesis infection was investigated in vitro. Discs of polymethylmethacrylate (PMMA) were exposed to a suspension containing cells of 10(8) per mL Staphylococcus epidermidis E-46. After 12 hours, exposed discs were rinsed with phosphate-buffered saline and placed in brain heart infusion broth containing antibiotics (2.5 mg per mL of Cephaloridine). After gentle shaking for 24 hours at 37 degrees C, the bacteria on the PMMA surface were detached and washed with phosphate-buffered saline to remove the antibiotics. Compared with the free bacteria which were detached from the PMMA by sonication immediately after exposure to the antibiotic solution, those allowed to remain adhered to the PMMA surface were more resistant to antibiotics. Scanning electron microscopy showed accumulation of bacteria surrounded by slime on PMMA discs exposed for 12 hours. Our results indicate that resistance of bacteria to antibiotics is increased after adherence to the biomaterial and formation of a slime layer.
Insights
Bacteria adhering to polymethylmethacrylate (PMMA) biomaterials become more resistant to antibiotics. This increased resistance is linked to slime layer formation, impacting total joint prosthesis infection treatment.
Area of Science:
- Biomaterials Science
- Microbiology
- Infectious Diseases
Background:
- Total joint prosthesis infections pose significant challenges in orthopedic surgery.
- Polymethylmethacrylate (PMMA) is a common biomaterial used in joint replacements.
- Understanding bacterial behavior on biomaterials is crucial for effective treatment.
Purpose of the Study:
- To investigate the in vitro pathobiology of total joint prosthesis infection.
- To determine the effect of biomaterial adherence on bacterial antibiotic resistance.
Main Methods:
- Exposing PMMA discs to Staphylococcus epidermidis E-46 suspensions in vitro.
- Treating adhered bacteria with Cephaloridine antibiotics.
- Comparing antibiotic resistance of adhered versus free-floating bacteria.
- Utilizing scanning electron microscopy to visualize bacterial accumulation and slime formation.
Main Results:
- Bacteria adhered to PMMA surfaces exhibited increased resistance to antibiotics compared to free bacteria.
- Scanning electron microscopy revealed significant accumulation of bacteria surrounded by slime on PMMA discs.
- Slime layer formation was observed after 12 hours of bacterial exposure.
Conclusions:
- Bacterial adherence to PMMA biomaterials enhances antibiotic resistance.
- The formation of a slime layer contributes to this increased resistance.
- These findings have implications for managing infections associated with orthopedic implants.