In Vitro Osteoblast Model for Bone Wound Infections and Antimicrobial Therapy (Addendum)
Technical Report,01 Dec 2010,31 Dec 2011
The Geneva Foundation Tacoma United States
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We proposed to determine the changes in osteoblast differentiation in vitro when infected with multidrug resistant bacteria and the therapeutic effects of two well characterized antimicrobial peptides. For the first part of the study, an in vitro 3 dimensional 3D model of primary human osteoblasts in a collagen scaffold was developed for infection. The 3D osteoblast cultures were infected with clinical isolates of multidrug resistant Acinetobacter baumannii, Klebsiella pneumoniae and Pseudomonas aeruginosa. Infection of osteoblasts revealed that all 3 species caninvade osteoblasts and can be detected at 7 days post infection. Our preliminary findings suggest that these intracellular Gram negative bacteria can also reinfect healthy osteoblasts. Current studies are underway to investigate primary osteoblast differentiation and maturation when infected with these bacteria by gene and protein expression. The temporal gene expression of infected osteoblasts in the 3D model was studied by real time PCR. Initial work suggested changes in expression of proinflammatory cytokines and other genes that may ultimately delay osteoblast differentiation and maturation of infected cells. Due to intracellular survival of these pathogens, therapy with antimicrobial peptides was not addressed in the present work, as antimicrobial peptides that penetrate osteoblasts need to be developed. The outcome of our findings will contribute to accelerate treatment options and management of osteomyelitis due to drug resistant bacteria in the Wounded Warrior.