Event Title
Media Conditioned by both Planktonic and Biofilm Bound Staphylococcus aureus Induces Cell Death in Osteocyte-like Cells
Location
Philadelphia, PA
Start Date
8-5-2019 1:00 PM
End Date
8-5-2019 4:00 PM
Description
Introduction: Staphylococcus aureus is the most common microbe found in association with bone infections. While previous work has shown that S. aureus can kill human osteoblasts in vitro, the role of the morphological state of the bacterium has not been evaluated. S. aureus can be found both in bacterial biofilms, thin layers of the bacteria grouped together, as well as suspended in solution, a planktonic state. It is hypothesized that these two different states may impact the effect the bacteria have on osteocyte-like cell viability.
Objective: The primary objective of this study was to evaluate cell viability of two different lines of osteocyte-like cells (MLO-A5 and MLO-Y4) after exposure to both biofilm and planktonic S. aureus conditioned media.
Methods: In this study, bacterial conditioned media was either formed from planktonic bacteria or bacteria within biofilms. This was completed by treating the bacteria for both conditions in media over a two-day incubation period. The media was then double filtered to remove any bacterium. Osteocyte-like cells (MLO-A5 and MLO-Y4) were exposed to 100%, 50%, 25%,10% and 5% conditioned media for a one- or four-hour incubation period. Cell viability was assessed using the MTT assay. Untreated cells were set as the control and all experimental data normalized to their value.
Results: When exposed to both cell types, undiluted conditioned media from both planktonic (PCM) and biofilm associated (BCM) bacteria created a significant decrease in cell viability in comparison to control conditions. MLO-Y4 cells showed a greater sensitivity to both types of conditioned media at one hour in comparison to MLO-A5 cells, although those differences appeared to have been lost by four hours. In both cell types, PCM appears to produce a greater reduction in cell viability than BCM at both one and four hours.
Conclusion: The data shows that conditioned media from planktonic S. aureus does have a greater effect in the viability of osteocyte-like cells. In addition, it appears as if MLO-Y4 cells, characteristic of a more mature osteocyte, are more sensitive to this conditioned media than the less mature MLO-A5 cells.
Embargo Period
5-24-2019
Media Conditioned by both Planktonic and Biofilm Bound Staphylococcus aureus Induces Cell Death in Osteocyte-like Cells
Philadelphia, PA
Introduction: Staphylococcus aureus is the most common microbe found in association with bone infections. While previous work has shown that S. aureus can kill human osteoblasts in vitro, the role of the morphological state of the bacterium has not been evaluated. S. aureus can be found both in bacterial biofilms, thin layers of the bacteria grouped together, as well as suspended in solution, a planktonic state. It is hypothesized that these two different states may impact the effect the bacteria have on osteocyte-like cell viability.
Objective: The primary objective of this study was to evaluate cell viability of two different lines of osteocyte-like cells (MLO-A5 and MLO-Y4) after exposure to both biofilm and planktonic S. aureus conditioned media.
Methods: In this study, bacterial conditioned media was either formed from planktonic bacteria or bacteria within biofilms. This was completed by treating the bacteria for both conditions in media over a two-day incubation period. The media was then double filtered to remove any bacterium. Osteocyte-like cells (MLO-A5 and MLO-Y4) were exposed to 100%, 50%, 25%,10% and 5% conditioned media for a one- or four-hour incubation period. Cell viability was assessed using the MTT assay. Untreated cells were set as the control and all experimental data normalized to their value.
Results: When exposed to both cell types, undiluted conditioned media from both planktonic (PCM) and biofilm associated (BCM) bacteria created a significant decrease in cell viability in comparison to control conditions. MLO-Y4 cells showed a greater sensitivity to both types of conditioned media at one hour in comparison to MLO-A5 cells, although those differences appeared to have been lost by four hours. In both cell types, PCM appears to produce a greater reduction in cell viability than BCM at both one and four hours.
Conclusion: The data shows that conditioned media from planktonic S. aureus does have a greater effect in the viability of osteocyte-like cells. In addition, it appears as if MLO-Y4 cells, characteristic of a more mature osteocyte, are more sensitive to this conditioned media than the less mature MLO-A5 cells.