Abstract

Catheter associated bloodstream infections, exit-site infections, and tunnel infections are common complications related to hemodialysis central venous catheter use. Effective antimicrobial coating of catheters that can inhibit device colonization has the potential of preventing clinical infection. The study investigated in vitro the antimicrobial efficacies of hemodialysis catheters impregnated with an antibiofilm agent (ascorbic acid) (vitamin C) and a broad-spectrum antibiotics (Gentamicin and levofloxacin) against five clinical strains recently isolated from patients undergoing hemodialysis catheter removal. Impregnated catheters were also evaluated for their anti-adherence activities and durabilities. Levofloxacin/ascorbic acid (LEV/AS) catheters produced the most active and durable antimicrobial effect against both Gram-positive and Gram-negative isolates and significantly reduced adherence (P<0.05) by all tested pathogens compared to control catheters while, gentamicin/ascorbic acid (GENT/AS) catheters had lost activity against methicillin resistant Staphylococcus aureus and Escherichia coli but still produced zones of inhibition only for methicillin-resistant Staphylococcus epidermidis (MRSE), Klebsiella pneumoniae and Pseudomonas aeruginosa. Effects of levofloxacin, gentamicin and vitamin C coated catheters on microbial adherence were found to be dose dependent. In conclusion, catheters impregnated with LEV/AS were shown to have broad spectrum, sustained antimicrobial durability and high efficacy. These in vitro results suggest that this antimicrobial combination can be used to protect against hemodialysis catheter colonization and catheter-associated infection.

Key words: Gentamicin-levofloxacin-ascorbic acid (vitamin C), biofilm, hemodialysis catheters, colonization.