Study of Staphylococcus aureus Biofilm Ability to Destroy Bone Matrix in Absences of Host Immunity (original) (raw)

Purpose: Osteomyelitis is an infectious bone process leading to bone necrosis and destruction. Published reports on pathogen biofilm thus far have focused on indirect bone resorption mediated by host cells and factors secondary to immune system activation. However, direct bone resorption due to biofilm pathogen has not been adequately studied yet. This study aims to investigate the effect of biofilm pathogen in ex-vivo human bones in the absence of the host immune response using Raman spectroscopy and Scanning electron microscopy. Methods: Bone samples collected from patients who underwent knee replacement surgeries were inoculated with Staphylococcus aureus bacteria. Bacterial direct effects on the bone quality were then examined, at various time intervals, using Raman spectroscopy and scanning electron microscopy. Results: Raman spectroscopy and scanning electron demonstrated the destruction of bone structure and drop in bone quality. Conclusion: This experiment shows the direct effect of bacteria on bone during osteomyelitis in addition to the recognised destruction caused by the host immune system. Introduction: Osteomyelitis (OM) is bone inflammatory process secondary to an infectious organism leading to bone necrosis and destruction. Bone is a sterile organ resistant to bacterial colonisation. However, events like trauma, surgery, or hematogenous spread of virulent pathogen may disturb structural integrity and results in infection (1). Several confounding factors may influence the inflammatory process of OM leading to diagnostic difficulties and treatment delays. Due to the marked variability in osteomyelitis presentation and treatment, many researchers tried to investigate disease pathogenesis and introduce a controlled approach to active management. However, the primary focus of most of the published reports was a collection of infection-related parameters: haematological, radiological, histology or bacterial culture (2). Some reports focused on the process of bone destruction due to immune system activation. However, there is limited emphasis on biofilm formation and pathogen-induced bone destruction (3). Most causative pathogens can adhere to and grow on the surface of bone, joints and prosthesis causing bone resorptions. The pathophysiology of bacterium-induced bone resorption has not been identified. However, reports have suggested that pathogens such as Staphylococcus aureus express an array of cell surface and soluble molecules (e.g. acids and proteases) that have the potential to promote bone destruction at the infection site (4). These molecules can either induce immune system activation or direct bone resorption due to their osteolytic properties. Published reports on pathogen biofilm thus far have focused on indirect bone resorption mediated by host cells and factors secondary to immune system activation (3, 5, 6). However, direct bone resorption due to biofilm pathogen excretions has not been adequately studied yet. Therefore, we planned to investigate the effect of biofilm pathogen in ex-vivo human bones in the absence of the .