A bacterial biofilm is a complex community of bacteria embedded within a self-produced matrix (ie, slime).1,2 An example of a bacterial biofilm is the slimy surface that accumulates in water bowls or the plaque that forms on teeth. In natural environments, bacteria exist in 2 states: the planktonic (ie, free-floating or nonbiofilm-embedded) state or the biofilm-embedded (ie, adhered to a surface) state.2 The planktonic state is important in the replication and growth of bacteria; however, bacteria have a tendency to congregate together and adhere to a surface.2 The biofilm-embedded state enables this congregation and adherence, which also allows for protection from harsh environmental conditions.2 Bacterial biofilms have been associated with persistent surgical site, wound, and urinary tract infections.2
Biofilm formation is a complex process during which bacteria adhere to a noninert (ie, living [eg, GI tract, teeth, gums]) or inert surface (eg, surgical implant, catheter, suture), grow, and produce a film-like matrix to protect themselves from the host immune response and antimicrobial therapy.2,3 For reasons yet to be determined, when bacteria detach from the biofilm, planktonic bacteria are released from the biofilm, which enables dissemination of the infection and potentially leads to biofilm formation and reattachment at other distant sites.2,3 The detachment phase may occur when the biofilm’s nutrient resources have been depleted.1,2 The detachment phase may occur days, weeks, or even years after initial biofilm formation and can result in clinical signs of planktonic infection.1,2 For example, the authors have observed implant-associated infections several years after surgery and have speculated that this is a result of the detachment of planktonic bacteria from a biofilm associated with the surgical implant.
Common causes of biofilm-associated infection include orthopedic implant infections (often caused by Staphylococcus pseudintermedius and other gram-positive pathogens), urinary tract and catheter-associated infections (eg, Escherichia coli), dental plaque formation and gingivitis (eg, Neisseria spp), and otitis (eg, Pseudomonas aeruginosa).3
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