JAC Advance Access originally published online on March 12, 2009
Journal of Antimicrobial Chemotherapy 2009 63(5):937-945; doi:10.1093/jac/dkp060
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Original research |
Effect of a solution containing citrate/Methylene Blue/parabens on Staphylococcus aureus bacteria and biofilm, and comparison with various heparin solutions
1 Department of Biological Sciences, SUNY at Binghamton, 148 Science III, Vestal Parkway East, Binghamton, NY, USA 2 R&D, Ash Access Technology, Inc., 3601 Sagamore Parkway North, Lafayette, IN, USA 3 Clarian Arnett Health, 5165 McCarty Lane, Lafayette, IN, USA 4 School of Veterinary Medicine Purdue University, 625 Harrison Street, West Lafayette, IN, USA
Received 22 December 2008; returned 19 January 2009; revised 30 January 2009; accepted 31 January 2009
* Corresponding author. Tel: +1-765-742-4813; Fax: +1-765-742-4823; E-mail: jsteczko{at}ashaccess.com
Objectives: Some antibiotic solutions increase bacterial resistance and may cause toxic side effects. Heparin, frequently used as an anticoagulant in catheter lock solutions, may cause bleeding and stimulate biofilm formation. The aim of this study was to investigate the effect of a new antibacterial/antithrombotic solution, citrate/Methylene Blue/parabens (C/MB/P), versus various heparin solutions on the viability and the structure of preformed mature biofilms of Staphylococcus aureus bacteria. The degree of eradication of both planktonic and sessile microorganisms was evaluated.
Methods: The changes in the structure of biofilms after exposure to C/MB/P and several concentrations of heparin were analysed by means of confocal laser scanning microscopy. COMSTAT image analysis was utilized to compare biofilm biomass, average and maximum height, surface coverage and roughness coefficient. Viability studies were performed on both biofilms and supernatant solutions.
Results: C/MB/P, in contrast to heparin solutions, significantly reduced biofilm biomass and thickness and reduced viability by 5 log when compared with saline treatment. No viable planktonic bacteria were detected and the few remaining biofilm cells appeared to be lysed. In contrast, most heparin solutions only reduced viability up to 1.0 log and failed to eradicate planktonic bacteria.
Conclusions: C/MB/P has a rapid bactericidal effect on the preformed, mature biofilm of S. aureus. The structural changes of biofilms treated with C/MB/P, together with the observed log reduction of viable biofilm cells, confirmed the high potential of this solution to eliminate sessile bacteria. Furthermore, the tested solution entirely eliminated planktonic bacteria detached from the biofilm.
Keywords: catheter infection , CRBSI , haemodialysis , lock solution , antimicrobial effect