Associate Professor, Small Animal Surgery Mississippi State University Mississippi State, Mississippi
Effect of a Poloxamer 407-Vancomycin Compound on In Vitro Biofilms. Swanson EA1, Hixon LP2, Burnette JB1. 1Mississippi State University, College of Veterinary Medicine, Mississippi State, MS; 2University of Georgia, College of Veterinary Medicine, Athens, GA.
The purpose of this study was to measure the effect of a poloxamer gel-vancomycin compound on an in vitro multidrug-resistant (MDR) biofilm. We hypothesized that biofilms treated with poloxamer gel-vancomycin compound would resolve, while biofilms treated with poloxamer gel alone would not. A clinical isolate of MDR Enterococcus faecium was grown on 54 polycarbonate coupons for 72 hours. Samples were treated with either 25% P-407 gel + 20 mg/mL vancomycin (PV) or 25% P-407 gel (P). Three samples in each group were stained with SYBR green fluorescent stain and imaged with a confocal microscope at 0, 4, 8, 12, 16, 20, 24, 36, or 48 hours; biofilm thickness and 3D morphology were recorded. Biofilms in the PV group decreased in thickness, developed holes, and dispersed bacteria onto the underlying plate. There was a significant difference in biofilm thickness between treatment groups at 8, 12, 16, 24, 36, and 48 hours. The PV biofilm thickness significantly decreased from 0 to 48 h (P = 0.03) There was no significant difference in biofilm thickness over time in the P group. The PV group biofilms flattened out in 3D reconstruction and the P group biofilms did not. Treatment with poloxamer 407-vancomycin gel significantly decreased biofilm thickness compared to poloxamer gel alone. Limitations include the in vitro limitations and unknown normal growth curve of bacteria. This gel compound could allow for more local control of infections in a continuous emergence of multidrug-resistant bacteria. A prospective time-course study is underway.