Recurring and antimicrobial-resistant infections:considering the potential role of biofilms in clinical practice.

Micro-organisms commonly produce biofilm, a polymeric matrix that is adherent to inert or living substances and frequently forms on environmental surfaces, medical devices, and traumatized or compromised living and nonviable necrotic tissues such as wounds. The micro-organisms in a biofilm interact with each other and their environment. They are refractory to conventional therapy and resist conventional methods for culturing; their coordinated activities can lessen the effect of antimicrobials and the host's defenses. The multifactorial mechanism of resistance varies and depends, in part, on the strain of the micro-organism. A biofilm is dynamic and may shed bacteria or bacteria may be released by trauma, resulting in local or systemic infectious disease. Released bacteria lose their protection - they become responsive to appropriate levels of antimicrobials and may be cultured using conventional culturing methods. Micro-organisms in biofilms may remain dormant for weeks or years before causing local or systemic signs and symptoms of infection and are commonly responsible for recurring infections after repeated trials of antibiotics. Most biofilm infection-related research findings have not reached clinical practice yet. However, clinician knowledge about the development of and difficulties culturing micro-organisms in biofilms and their resistance to antibiotics and biocides may lead to improved clinical outcomes in soft tissue and bone infections and the treatment of wounds.