When to Escalate
How Biofilm Sustains Device Infection
A biofilm is an organized microbial community attached to a surface and enclosed in a self produced extracellular polymeric matrix.
A biofilm is an organized microbial community attached to a surface and enclosed in a self-produced extracellular polymeric matrix. On an intravascular catheter, organisms may attach after skin organisms migrate along the insertion site, after a contaminated hub is accessed, or after organisms in the bloodstream seed the device. The matrix acts like a hydrated barrier around a densely occupied surface. It reduces access by immune cells and antimicrobial agents, while some organisms enter a low-metabolic state that makes them less susceptible to drugs aimed at actively dividing cells. The result is persistent colonisation rather than a brief, easily cleared contamination. Organisms can also detach intermittently, producing episodic bloodstream exposure, fever, chills, or positive cultures. Device-related infection is therefore not only an organism problem. It is an organism-plus-surface problem. Antibiotics may suppress circulating bacteria while the colonised device continues to release organisms. This is why source control—deciding whether the device must be removed—matters alongside antimicrobial treatment. The same principle applies to other indwelling devices. Urinary catheters can support biofilm and catheter-associated urinary tract infection; endotracheal tubes can support microbial accumulation...