Visualization of microbial biofilm in contaminated polymer tubes by X-ray micro-computed tomography and contrast agents

Senck, S. (Speaker), Kastner, J. (Speaker), Jäger, A. (Speaker), Jasmin Marleen Grabmair (Speaker), Matthias Aigner (Speaker)

Activity: Talk or presentationOral presentation


Bacterial biofilms form primarily on solid surfaces and play an important role in the pathogenesis of foreign body-associated infections. This is of major clinical importance when polymer surfaces, e.g. of catheters and prostheses, are colonized by microbial biofilms that cause chronic infections. Biofilms on medical devices, for example of Staphylococcus epidermidis and S. aureus, were already detected in the early 1980s using scanning electron microscopy. However, the three-dimensional visualization of biofilms can only be achieved using X-ray micro-computed tomography (µXCT). To effectively visualize soft tissue, structures of interest have to be labelled with contrast agents, such as iodine or barium which absorb X-rays efficiently. Barium sulfate (BaSO4) does not diffuse into the cells due to its insolubility in water and does not penetrate the biofilm itself. We applied BaSO4 to silicon tubes that were contaminated in vitro by a mixed bacterial culture and scanned these samples with a voxel size of 4 µm using a GE Phoenix Nanotom 180 NF. Due to the higher X-ray absorption of the polymer tube and BaSO4 the biofilm can be differentiated from the tube wall and contrast agent. Using this novel µXCT approach we are able to visualize the three-dimensional distribution of biofilm in polymer tubes simulating conditions that can be found in medical catheters. This provides new insights in biofilm development and offers an additional tool in the detection of biofilms. Furthermore, this approach is of potential use in the non-destructive testing of complex surfaces in medical devices that are susceptible to contamination.
Period24 Jun 2015
Event titleEurobiofilms: null
Event typeWorkshop
LocationBrno, Czech Republic