This Article
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrowReprints and Permissions
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Stoodley, P.
Right arrow Articles by Lappin-Scott, H. M.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Stoodley, P.
Right arrow Articles by Lappin-Scott, H. M.

 Previous Article  |  Next Article 

Antimicrobial Agents and Chemotherapy, 09 1997, 1876-1879, Vol 41, No. 9
Copyright © 1997 by the American Society for Microbiology. All rights reserved.

Influence of electric fields and pH on biofilm structure as related to the bioelectric effect

P Stoodley, D deBeer and HM Lappin-Scott
Department of Biological Sciences, University of Exeter, United Kingdom. P.Stoodley@exeter.ac.uk

Mixed species biofilms of Klebsiella pneumoniae, Pseudomonas fluorescens, and Pseudomonas aeruginosa were grown in a flow cell fitted with two platinum wire electrodes. The biofilm growing on the wires reached a thickness of approximately 50 microm after 3 days. When a voltage was applied with oscillating polarity, the biofilm attached to the wire expanded and contracted. The biofilm expanded by approximately 4% when the wire was cathodic but was reduced to 74% of the original thickness when the wire was anodic. The phenomenon was reproduced by alternately flushing the flow cell with media adjusted to pH 3 and pH 10 with no electric current. At pH 10 the biofilm was unaltered, but it became compacted to 69% of the original thickness at pH 3. We explained these phenomena in terms of the molecular interactions between charged acidic groups in the biofilm slime and the bacterial cell walls. Contraction of the biofilm under acidic conditions may be caused by (i) the elimination of electrostatic repulsion from neutralization of negatively charged carboxylate groups through protonation and (ii) subsequent hydrogen bonding between the carboxylic acids and oxygen atoms in the sugars. Electrostatic interactions between negatively charged groups in the biofilm and the charged wire may also be expected to cause biofilm expansion when the wire was cathodic and contraction when the wire was anodic. The consequences of the explanation of the increased susceptibility of biofilm cells to antibiotics in an electric field, the "bioelectric effect," are discussed.


This article has been cited by other articles:

  • del Pozo, J. L., Rouse, M. S., Mandrekar, J. N., Sampedro, M. F., Steckelberg, J. M., Patel, R. (2009). Effect of Electrical Current on the Activities of Antimicrobial Agents against Pseudomonas aeruginosa, Staphylococcus aureus, and Staphylococcus epidermidis Biofilms. Antimicrob. Agents Chemother. 53: 35-40 [Abstract] [Full Text]  
  • Giladi, M., Porat, Y., Blatt, A., Wasserman, Y., Kirson, E. D., Dekel, E., Palti, Y. (2008). Microbial Growth Inhibition by Alternating Electric Fields. Antimicrob. Agents Chemother. 52: 3517-3522 [Abstract] [Full Text]  
  • Stoodley, P., Wefel, J., Gieseke, A., deBeer, D., von Ohle, C. (2008). Biofilm Plaque and Hydrodynamic Effects on Mass Transfer, Fluoride Delivery and Caries. Journal of the American Dental Association 139: 1182-1190 [Abstract] [Full Text]  
  • Shirtliff, M. E., Bargmeyer, A., Camper, A. K. (2005). Assessment of the Ability of the Bioelectric Effect To Eliminate Mixed-Species Biofilms. Appl. Environ. Microbiol. 71: 6379-6382 [Abstract] [Full Text]  
  • Hunter, R. C., Beveridge, T. J. (2005). Application of a pH-Sensitive Fluoroprobe (C-SNARF-4) for pH Microenvironment Analysis in Pseudomonas aeruginosa Biofilms. Appl. Environ. Microbiol. 71: 2501-2510 [Abstract] [Full Text]  
  • Caubet, R., Pedarros-Caubet, F., Chu, M., Freye, E., de Belem Rodrigues, M., Moreau, J. M., Ellison, W. J. (2004). A Radio Frequency Electric Current Enhances Antibiotic Efficacy against Bacterial Biofilms. Antimicrob. Agents Chemother. 48: 4662-4664 [Abstract] [Full Text]  
  • Chandra, J., Kuhn, D. M., Mukherjee, P. K., Hoyer, L. L., McCormick, T., Ghannoum, M. A. (2001). Biofilm Formation by the Fungal Pathogen Candida albicans: Development, Architecture, and Drug Resistance. J. Bacteriol. 183: 5385-5394 [Abstract] [Full Text]  
  • Stewart, P. S., Wattanakaroon, W., Goodrum, L., Fortun, S. M., McLeod, B. R. (1999). Electrolytic Generation of Oxygen Partially Explains Electrical Enhancement of Tobramycin Efficacy against Pseudomonas aeruginosa Biofilm. Antimicrob. Agents Chemother. 43: 292-296 [Abstract] [Full Text]  
  • Souli, M., Giamarellou, H. (1998). Effects of Slime Produced by Clinical Isolates of Coagulase-Negative Staphylococci on Activities of Various Antimicrobial Agents. Antimicrob. Agents Chemother. 42: 939-941 [Abstract] [Full Text]  


Copyright © 2009 by the American Society for Microbiology.   For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»