Propagation of anaerobic bacteria within an aerobic multi-species chronic wound biofilm model

Abstract

Most chronic wound biofilms have been shown to have significant populations of anaerobes. In order to better screen antimicrobial and antibiofilm therapeutics, we evaluated the ability of key anaerobes to incorporate and propagate within our aerobic chronic wound biofilm. We had previously developed a rapid model to simulate polymicrobial chronic wound biofilms. This model incorporated meticillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococcus faecalis (VRE) and Pseudomonas aeruginosa. The model was used along with a variety of anaerobes to determine whether this biofilm model would support propagation of anaerobes similar to that we have identified in chronic wounds. Using our previously defined Lubbock Chronic Wound Biofilm (LCWB) model combined with quantitative PCR, anaerobic bacteria were shown to proliferate through integration into the biofilm under aerobic conditions. Using electron microscopy we show close association between aerobes and anaerobes within the biofilm suggesting a synergistic relationship. We have expanded the utility of the LCBW to show the ability of clinically significant anaerobic bacteria to thrive in aerobic conditions. The expansion of this model can further simulate the functional characteristics of chronic wound pathogenic biofilms and the species that dwell within them allowing improved ability to evaluate therapeutics that target anaerobes.