Summary of the invention
VIB scientists have developed a in vivo model to study Candida biofilm formation on implanted biomaterials. Microbial growth on implanted biomaterials including urinary and vascular catheters, joint and voice prostheses, ocular lenses, represent more than half of all human microbial infections.
In this subcutaneous biofilm model, small polyurethane biomaterials are challenged with Candida cells and implanted avascularly underneath the skin of rats. We are currently able to produce up to 80 biofilms simultaneously, which dramatically increases the statistical value of the antifungal activity tested. Biofilms in this system are developing within the first 48 hours after implant, and they reproducibly are composed of more than 3log10 cells. After that initial stage of development, biofilms are stable and mature by producing extracellular material. We are currently developing the system for live bioluminescence imaging in mice.
Our new subcutaneous in vivo rat model can be used to study the inhibitory activity of known or novel antimicrobial compounds in three different ways:
a prophylactic approach, where animals can be treated before implant of the infected devices (in order to test inhibition of the biofilm development),
a preventive manner, where antifungal agents are employed to coat biomaterial surfaces before implant in vivo,
a curative approach, where animals are subject to daily treatment with the antifungal agent. With this model we can hence analyze the activity of a compound against various stages of Candida biofilm, including adhesion, biofilm formation (usually during 48h), and mature biofilms (usually conducted over a period of 6 to 9 days).
The method was recently published in Microbiology:
Ricicova M. et al. (2010) Candida albicans bioifilm formation in a new in vivo rat model. Microbiology. 156: 909‐919.