Current Microbiology

, Volume 61, Issue 2, pp 148–156 | Cite as

Isolate-Specific Effects of Patulin, Penicillic Acid and EDTA on Biofilm Formation and Growth of Dental Unit Water Line Biofilm Isolates

  • Iram Liaqat
  • Robert Thomas Bachmann
  • Anjum Nasim Sabri
  • Robert G. J. Edyvean


Dental unit water line (DUWL) contamination by opportunistic pathogens has its significance in nosocomial infection of patients, health care workers, and life-threatening infections to immunocompromized persons. Recently, the quorum sensing (QS) system of DUWL isolates has been found to affect their biofilm-forming ability, making it an attractive target for antimicrobial therapy. In this study, the effect of two quorum-sensing inhibitory compounds (patulin; PAT, penicillic acid; PA) and EDTA on planktonic growth, AI-2 signalling and in vitro biofilm formation of Pseudomonas aeruginosa, Achromobacter xylosoxidans and Achromobacter sp. was monitored. Vibrio harveyi BB170 bioassay and crystal violet staining methods were used to detect the AI-2 monitoring and biofilm formation in DUWL isolates, respectively. The V. harveyi BB170 bioassay failed to induce bioluminescence in A. xylosoxidans and Achromobacter sp., while P. aeruginosa showed AI-2 like activity suggesting the need of some pretreatments prior to bioassay. All strains were found to form biofilms within 72 h of incubation. The QSIs/EDTA combination have isolate-specific effects on biofilm formation and in some cases it stimulated biofilm formation as often as it was inhibited. However, detailed information about the anti-biofilm effect of these compounds is still lacking.


Quorum Sense Patulin Quorum Sense System luxS Gene Penicillic Acid 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


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Copyright information

© Springer Science+Business Media, LLC 2010

Authors and Affiliations

  • Iram Liaqat
    • 1
    • 2
  • Robert Thomas Bachmann
    • 3
    • 4
  • Anjum Nasim Sabri
    • 1
  • Robert G. J. Edyvean
    • 3
  1. 1.Department of Microbiology and Molecular GeneticsUniversity of the PunjabLahorePakistan
  2. 2.Department of BiosciencesCOMSATS Institute of Information TechnologySahiwalPakistan
  3. 3.Department of Chemical and Process Engineering, Kroto Research Institute The University of SheffieldSheffieldUK
  4. 4.Malaysian Institute of Chemical and Bioengineering TechnologyUniversiti Kuala LumpurMelakaMalaysia

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