This Article
Right arrow Full Text
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 Walker, J. T.
Right arrow Articles by Marsh, P. D.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Walker, J. T.
Right arrow Articles by Marsh, P. D.
Agricola
Right arrow Articles by Walker, J. T.
Right arrow Articles by Marsh, P. D.

 Previous Article  |  Next Article 

Applied and Environmental Microbiology, August 2000, p. 3363-3367, Vol. 66, No. 8
0099-2240/00/$04.00+0
Copyright © 2000, American Society for Microbiology. All rights reserved.

Microbial Biofilm Formation and Contamination of Dental-Unit Water Systems in General Dental Practice

James T. Walker,1 David J. Bradshaw,1 Allan M. Bennett,1 Martin R. Fulford,2 Michael V. Martin,3 and Philip D. Marsh1,4

CAMR, Porton Down, Salisbury, SP4 0JG,1 Dental Practice, Town Street, Shepton Mallet BA45 BE,2 Department of Clinical Dental Sciences, University of Liverpool, Liverpool, L69 3BX,3 and Leeds Dental Institute, Leeds, LS2 9LU,4 United Kingdom

Received 24 February 2000/Accepted 4 May 2000

Dental-unit water systems (DUWS) harbor bacterial biofilms, which may serve as a haven for pathogens. The aim of this study was to investigate the microbial load of water from DUWS in general dental practices and the biofouling of DUWS tubing. Water and tube samples were taken from 55 dental surgeries in southwestern England. Contamination was determined by viable counts on environmentally selective, clinically selective, and pathogen-selective media, and biofouling was determined by using microscopic and image analysis techniques. Microbial loading ranged from 500 to 105 CFU · ml-1; in 95% of DUWS water samples, it exceeded European Union drinking water guidelines and in 83% it exceeded American Dental Association DUWS standards. Among visible bacteria, 68% were viable by BacLight staining, but only 5% of this "viable by BacLight" fraction produced colonies on agar plates. Legionella pneumophila, Mycobacterium spp., Candida spp., and Pseudomonas spp. were detected in one, five, two, and nine different surgeries, respectively. Presumptive oral streptococci and Fusobacterium spp. were detected in four and one surgeries, respectively, suggesting back siphonage and failure of antiretraction devices. Hepatitis B virus was never detected. Decontamination strategies (5 of 55 surgeries) significantly reduced biofilm coverage but significantly increased microbial numbers in the water phase (in both cases, P < 0.05). Microbial loads were not significantly different in DUWS fed with soft, hard, deionized, or distilled water or in different DUWS (main, tank, or bottle fed). Microbiologically, no DUWS can be considered "cleaner" than others. DUWS deliver water to patients with microbial levels exceeding those considered safe for drinking water.


Applied and Environmental Microbiology, August 2000, p. 3363-3367, Vol. 66, No. 8
0099-2240/00/$04.00+0
Copyright © 2000, American Society for Microbiology. All rights reserved.



This article has been cited by other articles:

  • Barben, J., Schmid, J. (2008). Dental units as infection sources of Pseudomonas aeruginosa. Eur Respir J 32: 1122-1123 [Full Text]  
  • Yabune, T., Imazato, S., Ebisu, S. (2008). Assessment of Inhibitory Effects of Fluoride-Coated Tubes on Biofilm Formation by Using the In Vitro Dental Unit Waterline Biofilm Model. Appl. Environ. Microbiol. 74: 5958-5964 [Abstract] [Full Text]  
  • Schel, A. J., Marsh, P. D., Bradshaw, D. J., Finney, M., Fulford, M. R., Frandsen, E., Ostergaard, E., ten Cate, J. M., Moorer, W. R., Mavridou, A., Kamma, J. J., Mandilara, G., Stosser, L., Kneist, S., Araujo, R., Contreras, N., Goroncy-Bermes, P., O'Mullane, D., Burke, F., O'Reilly, P., Hourigan, G., O'Sullivan, M., Holman, R., Walker, J. T. (2006). Comparison of the Efficacies of Disinfectants To Control Microbial Contamination in Dental Unit Water Systems in General Dental Practices across the European Union. Appl. Environ. Microbiol. 72: 1380-1387 [Abstract] [Full Text]  
  • Piao, Z., Sze, C. C., Barysheva, O., Iida, K.-i., Yoshida, S.-i. (2006). Temperature-Regulated Formation of Mycelial Mat-Like Biofilms by Legionella pneumophila. Appl. Environ. Microbiol. 72: 1613-1622 [Abstract] [Full Text]  
  • Chaw, K. C., Manimaran, M., Tay, F. E. H. (2005). Role of Silver Ions in Destabilization of Intermolecular Adhesion Forces Measured by Atomic Force Microscopy in Staphylococcus epidermidis Biofilms. Antimicrob. Agents Chemother. 49: 4853-4859 [Abstract] [Full Text]  
  • Borella, P., Montagna, M. T., Stampi, S., Stancanelli, G., Romano-Spica, V., Triassi, M., Marchesi, I., Bargellini, A., Tato, D., Napoli, C., Zanetti, F., Leoni, E., Moro, M., Scaltriti, S., Ribera D'Alcala, G., Santarpia, R., Boccia, S. (2005). Legionella Contamination in Hot Water of Italian Hotels. Appl. Environ. Microbiol. 71: 5805-5813 [Abstract] [Full Text]  
  • McDOWELL, J. W., PAULSON, D. S., MITCHELL, J. A. (2004). A simulated-use evaluation of a strategy for preventing biofilm formation in dental unit waterlines. Journal of the American Dental Association 135: 799-805 [Abstract] [Full Text]  
  • Walker, J. T., Bradshaw, D. J., Fulford, M. R., Marsh, P. D. (2003). Microbiological Evaluation of a Range of Disinfectant Products To Control Mixed-Species Biofilm Contamination in a Laboratory Model of a Dental Unit Water System. Appl. Environ. Microbiol. 69: 3327-3332 [Abstract] [Full Text]