How bacterial biofilms affect chronic wound healing: a narrative review
Bhargav Gajula, Sinduja Munnamgi, Somprakas Basu
Abstract
Bacterial biofilm is a formidable influencing factor affecting healing of chronic wound. The mechanisms are as diverse as the bacterial species contained in the biofilm. In an altered environment the biofilm accommodates polymicrobial colonies in which micro-organisms undergo phenotypic and genetic changes to sustain adverse environmental influence. Biofilm bacteria inhibits cell proliferation, prevents cell migration and cause cell kill in a number of ways. It is believed that different bacterium has different mode of action through elaboration of various bioactive factors leading to persistence of low-grade inflammation in the wound bed which is predominantly bacteria-centric. Their ability to survive in low oxygen tension allows them to persist in relatively hypoxic conditions in the wound bed and in presence of increased bioburden. Although the biochemical mechanisms of biofilm influence on chronic wound healing are unfolding slowly, it is difficult to develop clinical studies due to ethical concerns. Therefore, most of the accumulated evidence are based on animal models and in vitro studies. This narrative review attempts to focus on the various mechanisms responsible for delayed healing in presence of bacterial biofilms.