Deciphering the Contribution of Bacterial Biofilms to Persistent Chronic Infections and Multidrug Antibiotic Resistance Mechanisms

Abstract

Bacterial biofilms are organized microbial communities that attach to living or nonliving surfaces and become embedded in a self-produced extracellular matrix composed of polysaccharides, proteins, and extracellular DNA. This growth pattern promotes survival under adverse environmental conditions and contributes to the persistence of infections. This overview examines biofilm development, mechanisms underlying reduced antibiotic susceptibility, and approaches to preventing and controlling biofilm-associated infections. Biofilm formation generally proceeds through initial surface attachment, irreversible adhesion, microcolony formation, maturation into a three-dimensional structure, and dispersal of cells capable of colonizing additional surfaces. Adhesion molecules, extracellular matrix production, and quorum-sensing systems contribute to the establishment and organization of biofilms in many pathogenic bacteria. Biofilms are clinically important because of their association with chronic infections and infections involving implanted medical devices. Their persistence reflects several interacting mechanisms, including limited penetration of some antibiotics, altered bacterial metabolic activity, and the presence of dormant persister cells. Biofilm communities can also facilitate the transfer of genes that confer antibiotic resistance. Biofilm-associated antibiotic tolerance and genetically mediated resistance represent distinct mechanisms, both of which can complicate bacterial eradication. Preventive and therapeutic approaches include antimicrobial surface coatings, combination antibiotic therapy, enzymatic disruption of the extracellular matrix, and removal of contaminated medical devices when clinically indicated. Emerging approaches, including nanotechnology-based interventions and bacteriophage therapy, offer additional possibilities but require further evaluation of their effectiveness and applicability. The discussion highlights the importance of addressing bacterial cells, the protective matrix, and colonized surfaces when developing biofilm-control strategies. Further research should clarify how these approaches can be integrated to improve the prevention and management of persistent biofilm-associated infections.