Eradication of microorganisms embedded in biofilm by an ethanol-based catheter lock solution

• Published in: Nephrology, dialysis, transplantation Vol. 24; no. 10; pp. 3204 - 3209
• Main Authors: Balestrino, Damien, Souweine, Bertrand, Charbonnel, Nicolas, Lautrette, Alexandre, Aumeran, Claire, Traoré, Ousmane, Forestier, Christiane
• Format: Journal Article
• Language: English
• Published: Oxford Oxford University Press 01-10-2009
• Subjects: Anesthesia. Intensive care medicine. Transfusions. Cell therapy and gene therapy; biofilm; Biofilms - drug effects; Biological and medical sciences; Candida albicans; Candida albicans - drug effects; catheter; Catheterization; Citrates - pharmacology; Emergency and intensive care: renal failure. Dialysis management; Equipment Contamination; Ethanol - pharmacokinetics; infection; Intensive care medicine; Klebsiella pneumoniae; Klebsiella pneumoniae - drug effects; Life Sciences; lock solution; Medical sciences; Microbiology and Parasitology; Miscellaneous; Pseudomonas aeruginosa; Pseudomonas aeruginosa - drug effects; Public health. Hygiene; Public health. Hygiene-occupational medicine; Staphylococcus aureus; Staphylococcus aureus - drug effects; Staphylococcus epidermidis - drug effects; Time Factors; catheter; infection; lock solution; biofilm; Kidney disease; Infection; Extrarenal dialysis; Urinary system disease; Ethanol; Hemodialysis; Renal failure; Catheter; Microorganism
• ISSN: 0931-0509; 1460-2385
• DOI: 10.1093/ndt/gfp187

Background. Interdialytic locking of catheters with antimicrobial agents is frequently used for preventing catheter-related infections, often associated with biofilm formation. We determined the bactericidal effect of 60% ethanol (ETOH) versus a 46.7% trisodium citrate (TSC) solution on biofilm embedded in silicone catheters. Methods. Four- and 24-h biofilms of Staphylococcus aureus, S. epidermidis, Pseudomonas aeruginosa, Klebsiella pneumoniae and Candida albicans established in a microfermentor were exposed to ETOH and TSC for up to 24 h and the number of remaining viable microorganisms was determined. Results. ETOH 60% was significantly more effective than 46.7% TSC in rapidly eradicating sessile cells from all microorganisms tested. A 20-min ETOH 60% treatment completely eradicated the Gram-negative bacilli and C. albicans biofilms, which initially contained up to 108 and 105 cells, respectively. Gram-positive cocci biofilms only showed a significant 2.6–4.3 log reduction in the initial viable counts after 20 min of ETOH 60% treatment, with eradication occurring after 30 min. Confocal laser scanning microscopy observation of ETOH-treated biofilm showed sparse cells with respiratory activity. TSC 46.7% eradicated none of the tested microorganisms. In contrast, ETOH 60% totally eradicated planktonic cells, whereas TSC had significant bactericidal activity against K. pneumoniae, P. aeruginosa and C. albicans after 20 min, 1 and 24 h, respectively, but none on the Staphylococcus species. Conclusions. This in vitro study demonstrates the superior antimicrobial activity of ETOH 60% in contrast to TSC 46.7% in eradicating biofilm formed on a silicon catheter. Hence, ethanol-based solution shows promise as a catheter lock solution.