Investigating the effect of patulin, penicillic acid and EDTA on biofilm formation of isolates from dental unit water lines
This study investigated the effect of patulin and penicillic acid, two known quorum-sensing inhibitors, and the common biocide ethylenediaminetetraacetic acid (EDTA) on the biofilm formation and auto-inducer (AI)-2 production of three isolates from dental unit water lines, Klebsiella sp., Bacillus subtilis and Bacillus cereus. Penicillic acid on its own had no effect on the biofilm formation of all isolates, whereas in combination with EDTA, it enhanced biofilm formation significantly in Klebsiella sp. and B. cereus. EDTA at concentrations greater than 10 μM promoted biofilm formation in B. cereus and B. subtilis. Patulin was found to promote biofilm formation in B. cereus up to 25 μM. A significant increase in biofilm formation was observed in B. cereus and B. subtilis at concentrations greater than 10 μM of patulin when combined with EDTA. The Vibrio harveyi BB170 AI-2 bioassay showed a positive response for Klebsiella sp. AI-2 production with a maximum fold induction at the late exponential growth phase. Addition of glucose prolonged the AI-2 production phase considerably. No significant effect of patulin, penicillic acid alone as well as in combination with EDTA was observed on AI-2 production by Klebsiella sp. The findings have important implications for the design of biofilm prevention and eradication strategies.
KeywordsDUWL isolates Patulin Penicillic acid Biocide Biofilm assay AI-2 assay
The authors wish to thank Kevin Eboigbodin, Ammar Abdul Razak, Ernesto Hernandez and Johanna Andrews for their helpful discussion. We thank Michel Gohar for his timely guidance regarding our project. This work was funded by Higher Education Commission (HEC), Pakistan. The authors also wish to thank Professor Paul Williams (University of Nottingham, UK) for the V. harveyi strains for the AI-2 bioassay. Author Catherine Biggs also wishes to thank the Engineering and Physical Sciences Research Council UK for an advanced research fellowship (EP/E053556/1).
- Bassler BL, Greenberg EP, Stevens AM (1997) Cross-species induction of luminescence in the quorum-sensing bacterium Vibrio harveyi. J Bacteriol 179:4043–4045Google Scholar
- Christensen GD, Simpson WA, Younge J, Baddour LM, Barrett FF, Melton DM, Beachey EH (1985) Adherence of coagulasenegative staphylococci to plastic tissue culture plates: a quantitative model for the adherence of staphylococci to medical devices. J Clin Microbiol 22:996–1006Google Scholar
- Decho AW (1990) Microbial exopolymer secretions in ocean environments: their role(s) in food webs and marine processes. Oceanogr Mar Bio Annu Rev 28:73–153Google Scholar
- Frezza M, Soulère L, Balestrino D, Gohar M, Deshayes C, Queneau Y, Forestier C, Doutheau A (2007) Ac2-DPD, the bis-(O)-acetylated derivative of 4,5-dihydroxy-2,3-pentanedione (DPD) is a convenient stable precursor of bacterial quorum sensing autoinducer AI-2. Bioorg Med Chem Lett 17:1428–1431CrossRefGoogle Scholar
- Hentzer M, Givskov M (2003) Pharmacological inhibition of quorum sensing for the treatment of chronic bacterial infections. J Clin Invest 112:1300–1307Google Scholar
- Hentzer M, Riedel K, Rasmussen TB, Heydorn A, Andersen JB, Parsek MR, Rice SA, Eberl L, Moli S, Hoiby N, Kjelleberg S, Givskov M (2002) Inhibition of quorum sensing in Pseudomonas aeruginosa biofilm bacteria by a halogenated furanone compound. Microbiology 148:87–102Google Scholar
- Jones MB, Blaser MJ (2003) Detection of a luxS-signaling molecule in Bacillus anthracis. Infect Immun 71:914–3919Google Scholar
- Rasmussen TB, Skindersoe ME, Bjarnsholt T, Phipps RK, Christensen KB, Jensen PO, Andersen JB, Koch B, Larsen TO, Hentzer M, Eberl L, Hoiby N, Givskov M (2005a) Screening for quorum-sensing inhibitors (QSI) by use of a novel genetic system, the QSI selector. J Bacteriol 187:1799–1814CrossRefGoogle Scholar
- Sutherland I (2001) Biofilm EPS: a strong and sticky framework. Microbiology 147:3–9Google Scholar
- Tarkkanen AM, Allen BL, Williams PH, Kauppi M, Haahtela K, Siitonen A, Orskov I, Orskov F, Clegg S, Korhonen TK (1992) Fimbriation, capsulation, and iron-scavenging systems of Klebsiella strains associated with human urinary tract infection. Infect Immun 60:1187–1192Google Scholar
- Tuttlebee CM, O’Donnell MJ, Keane CT, Russell RJ, Sullivan DJ, Falkiner F, Coleman DC (2002) Effective control of dental chair unit waterline biofilm and marked reduction of bacterial contamination of output water using two peroxide-based disinfectants. J Hosp Infect 52:192–205CrossRefGoogle Scholar
- Vaara M (1992) Agents that increase the permeability of the outer membrane. Microbiol Rev 56:395–411Google Scholar