B-237. Growth of Anaerobic Clostridium perfringens and Peptoniphilus ivorii in an Aerobic Multi-Species Biofilm Model of Chronic Wounds

Y. Sun1, S. E. Dowd2, D. Rhoads1, E. Smith1, R. Wolcott1;
1Med. Biofilm Res. Inst., Lubbock, TX, 2USDA ARS, Lubbock, TX.

Multi-species biofilms are becoming increasingly recognized as the naturally occurring state in which bacteria reside. One of the primary health issues that is now recognized to be exacerbated by multi-species pathogenic biofilms are chronic, non-healing wounds such as venous leg ulcers, diabetic foot ulcers, and pressure ulcers. Arguably five of the more important species of bacteria associated with multi-species pathogenic biofilms are Pseudomonas aeruginosa, Enterococcus faecalis, Clostridium perfringens, Peptoniphilus ivorii (formerly Peptostreptococcus) and Staphylococcus aureus. This study was conducted to address the need for a 24 hour, chronic pathogenic biofilm laboratory model which allows for cooperative growth of these organisms. We have developed a novel media formulation, simple laboratory system, quantitative PCR for monitoring population dynamics, and methods for objectively and subjectively measuring biofilm formation. The Lubbock chronic wound pathogenic biofilm (LCWB) model withstood treatment with a fifty fold higher concentration of bleach than that which was completely bacteriocidal for fully turbid planktonic cultures. The LCWB when treated with biofilm effectors such as gallium nitrate and triclosan responded with selective inhibition of Pseudomonas or Staphylococcus spp. respectively as has been reported in the literature. The ability of this 24 hr model to react as predicted using known biofilm effectors suggests it will lend itself to future work in the development of first generation chronic wound pathogenic biofilm therapeutics. We have defined a realistic in vitro multi-species biofilm model simulating the functional characteristics of chronic pathogenic biofilms and developed effective tools for its characterization and analyses.