Central venous catheters (CVCs) are implantable intravascular medical devices used to deliver infusion
treatments such as chemotherapy, total parenteral nutrition or hemodialysis.
Between treatments, CVCs are filled with fluids called lock solutions. Locked CVCs become rapidly colonized with pathogenic microbes that form biofilm on the inside (luminal) surfaces. Locked catheters are reservoirs of disease. When CVCs are used for therapy, pathogens are released into the bloodstream placing patients at significant risk of sepsis.
Sepsis is a life-threatening bloodstream infection caused by microbial pathogens that results in significant patient morbidity and mortality, the treatment of which requires costly in-patient critical care and extended hospital stays.
Heparin dissolved in physiologic saline is the most commonly used catheter lock solution worldwide. Heparin is a multichain sugar molecule very similar in structure to carrageenan, which is the growth substrate used to culture bacterial and fungal microbes in the laboratory setting.
Heparin is used as a powerful anti-coagulant drug. The unintended consequence of using heparin as a catheter lock solution is that heparin also serves as a nutrient substrate that supports microbial growth. Accumulation of pathogenic biofilm inside catheters is encouraged by heparin and can result in life-threatening bloodstream infections.
Carrageenan is a multi-chain sugar molecule isolated from marine algae that is used as the growth substrate in agar plates for laboratory culture of bacterial and fungal microbes.