Rodent Implantable Biofilm Coated Devices
Duration of study – Up to 6 months
Lead time – 30 days
Standard results – Microbiology, Histology
Model utility:
The rat subcutaneous implant model is our most frequently requested (and most frequently recommended) animal model for screening antimicrobial and anti-biofilm actives and coatings. The model is fast, relatively inexpensive and, in our experience, 75-80% predictive of more complicated animal models. Using this model, it is possible to screen a wide array of microbial species with high reproducibility. Furthermore, as with all infection models, results are fast and unambiguous – actives that work generate significant log reductions compared to controls.
How the Model Works:
Device is implanted subcutaneously (typically a polypropylene hernia mesh)
Infection is added through precultured of the biofilm onto the material prior to implantation
Commonly requested bacteria are: MRSA, S. epidermidis, E. coli, and Pseudomonas
Treatment can begin any time before or after implantation
Implanted device and surrounding tissue are collected for microbial counts on both selective and non-selective media.
The surrounding tissue can also be evaluated histologically
Study duration can be hours up to 6 months
Example Data:
This data was generated from a model development study that assessed bioburden after inoculation of the test implants with various concentrations of Staphylococcus aureus and incubation for 30 minutes.
Figure 1. A comparison of total bioburden present on a silicone mesh inoculated with varying concentrations of S. aureus. Meshes were sampled at Day 7 and compared to control meshes that were not implanted and were sampled on Day 0.
Figure 2. A comparison of total Staphylococcus colony forming units (CFUs) present on a silicone mesh inoculated with varying concentrations of S. aureus. Meshes were sampled at Day 7 and compared to control meshes that were not implanted and were sampled on Day 0.