Introduction: Wounds that fail to heal within an expected time frame (i.e. hard-to-heal or chronic) represent significant challenges in healthcare, marked by a complex interplay between bacterial pathogens and the host's immune response. This is further challenged by the compromised immunity associated with our aging population as well as increasing chronic disease prevalence such as diabetes and obesity. One emerging factor contributing to the persistance of wound infection and chronicity is the existance of biofilms. Biofilm is the preferred and predominant mode of bacterial growth and involves communities of bacteria encased within a self-produced protective extracellular matrix which enhances bacterial tolerance to conventional antibiotics. This resiliance not only complicates wound infection management but also underscores the urgent need to revise understanding as well as therapeutic approaches. Without these revisions the rampant and indiscriminant use of antibiotics will continue to exacerbate our current global problem of antibiotic resistance, further diminishing the effectiveness of these critical drugs as well as intensify the complications associated with wound chronicity.
Methods: Review of current literature on acute and chronic wound infection, biofilm tolerance, host inflammatory response, antibiotic use with wounds, and antimicrobial stewardship
Results: There is objective, evidence-based research confirming the existence of two types of wound infection, acute and chronic, the latter of which relates to the tolerance of the biofilm phenotype. These different types of wound infection have unique clinical signs that interestingly coincide with early ideas about wound chronicity. There is evidence of two distinct wound infection pathologies that display contrasting clinical appearances and require distinctive treatment strategies. In a chronic wound infection biofilm promotes a 'parasitic' infection where it induces a perisistant frustrated, inflammatory state that is ineffective against the protected bacteria. This results in neutrophil release of toxic metabolites that destroy host tissue while the bacterial community is spared. This biofilm can then continue to exist, feeding off of dead host tissue resulting in a 'biofilm-hijacked' inflammation.
Discussion: A chronic wound is a chronic infection. An improved understanding of the distinctive characteristics of the two types of wound infection and how these relate to wound chronicity can promote more focused, effective wound management as well as help to limit ineffective use of antibiotics therefore helping to control our growing global problem related to antibiotic resistance.