Mesenchymal stromal cells (MSC) harvested in different tissues from the same donor exhibit different phenotypes. Each phenotype is not only characterized by a certain pattern of cell surface markers, but also different cellular functionalities. Only recently were different harvesting and processing techniques found to contribute to this phenomenon as well. This study was therefore set up to investigate proteomic and functional properties of human bone marrow-derived MSCs (hBM-MSC). These were taken from the same tissue and donor site but harvested either as aspirate or bone chip cultures. Both MSC populations were profiled for MSC markers defined by the International Society for Cellular Therapy (ISCT), MSC markers currently under discussion and markers of particular interest. While classic ISCT MSC markers did not show any significant difference between aspirate and outgrowth hBM-MSCs, our additional characterization panel revealed distinct patterns of differentially expressed markers. Furthermore, hBM-MSCs from aspirate cultures demonstrated a significantly higher osteogenic differentiation potential than outgrowth MSCs, which could be confirmed using a transcriptional approach. Our comparison of MSC phenotypes obtained by different harvesting techniques suggests the need of future standardized harvesting, processing and phenotyping procedures in order to gain better comparability in the MSC field.

Antibiotic therapy is essential in foreign body associated infections. The treatment regime should aim at high tissue concentrations, high bioavailability, high biofilm penetration and good tolerance. We investigated whether the new cephalosporin ceftobiprole is active against clinical isolates from musculoskeletal foreign body associated infections. One hundred ninety-six staphylococci isolates (coagulase negative staphylococci and Staphylococcus aureus) derived from foreign body associated infections were tested towards susceptibility to ceftobiprole, using a test strip assay and broth microdilution. The MIC for all strains S. aureus indicated susceptibility to ceftobiprole. The MIC of only two strains of coagulase negative staphylococci was above 2 mg/L. Our results show that ceftobiprole might be considered as an off-label treatment option in foreign body associated infections.