Share This Article:

Spions Increase Biofilm Formation by Pseudomonas aeruginosa

Full-Text HTML Download Download as PDF (Size:2121KB) PP. 508-518
DOI: 10.4236/jbnb.2012.324052    3,538 Downloads   6,471 Views   Citations


Limited research has suggested iron oxide nanoparticles (FeNP) have an inhibitory effect against several different genera of bacteria: Staphylococcus, Bacillus and Pseudomonas spp. In this study we looked at the effect of three different sets of Fe3O4 nanoparticles (FeNPs) on the development of Pseudomonas aeruginosa PAO1 biofilms. Two of the tested NPs were SPIONs (Superparamagnetic Iron Oxide Nanoparticles). Exposure of cells to the SPIONs at concentrations up to 200 μg/ml resulted in an increase in biofilm biomass by 16 h under static conditions and a corresponding increase in cell density in the bulk liquid. In contrast, these biofilms had decreased levels of extracellular DNA (eDNA). Fe(II) levels in the supernatants of biofilms formed in the presence of FeNPs exceeded 100 μM compared with 20 μM in control media without cells. Spent cell supernatants had little effect on Fe(II) levels. Cells also had an effect on the aggregation behavior of these nanoparticles. SPIONs incubated with cells exhibited a decrease in the number and size of FeNP aggregates visible using light microscopy. SPIONs resuspended in fresh media or spent culture supernatants formed large aggregates visible in the light microscope upon exposure to a supermagnet; and could be pelleted magnetically in microtitre plate wells. In contrast, SPION FeNPs incubated with cells were unaffected by exposure to the supermagnet and could not be pelleted. The results of this study indicate a need to reconsider the effects of FeNPs on bacterial growth and biofilm formation and the effect the bacterial cells may have on the use and recovery of SPIONs.

Cite this paper

C. Haney, J. Rowe and J. Robinson, "Spions Increase Biofilm Formation by Pseudomonas aeruginosa," Journal of Biomaterials and Nanobiotechnology, Vol. 3 No. 4A, 2012, pp. 508-518. doi: 10.4236/jbnb.2012.324052.


[1] Kenneth Todar,. 2008. Opportunistic infections caused by Pseudomonas aeruginosa. In Todar’s online textbook of bacteriology (
[2] N. Hoiby ,T. Bjarnsholt, M. Givskov, S. Molin, and O. Ciofu. 2010. Antibiotic resistance of bacterial biofilms. International Journal of Antimicrobial Agents 35 (4) (Apr): 322-32. doi:10.1016/j.ijantimicag.2009.12.011
[3] M.L.Vasil, and U. A. Ochsner. 1999. The response of Pseudomonas aeruginosa to iron: Genetics, biochemistry and virulence. Molecular Micro-biology 34 (3) (Nov): 399-413. doi:10.1046/j.1365-2958.1999.01586.x
[4] G. Papanikolaou, and K. Pantopoulos. 2005. Iron metabolism and toxicity. Toxicology and Applied Pharmacology 202 (2) (Jan 15): 199-211.
[5] U. A. Ochsner, and J. Reiser. 1995. Autoinducer-mediated regulation of rhamnolipid biosurfactant synthesis in Pseudomonas aeruginosa. Proceedings of the National Academy of Sciences of the United States of America 92 (14) (Jul 3): 6424-8.
[6] T. R. de Kievit, 2009. Quorum sensing in Pseudomonas aeruginosa biofilms. Environmental Microbiol-ogy 11 (2) (Feb): 279-88. doi:10.1111/j.1462-2920.2008.01792.x
[7] D. J. Musk., D. A. Banko, and P. J. Hergenrother. 2005. Iron salts perturb biofilm formation and disrupt existing biofilms of Pseudomonas aeru-ginosa. Chemistry & Biology 12 (7) (Jul): 789-96. doi:10.1016/j.chembiol.2005.05.007
[8] P. K.Singh, M. R. Parsek, E. P. Greenberg, and M. J. Welsh. 2002. A component of innate immunity prevents bacterial biofilm development. Nature 417 (6888) (May 30): 552-5.
[9] G. M. Patriquin, E. Banin, C. Gilmour, R. Tuchman, E. P. Greenberg, and K. Poole. 2008. Influence of quorum sensing and iron on twitching motility and biofilm formation in Pseudomonas aeruginosa. Journal of Bacteriology 190 (2) (Jan): 662-71. doi:10.1128/JB.01473-07
[10] C. Y. O'May, K. Sanderson, L. F. Roddam, S. M. Kirov, and D. W. Reid. 2009. Iron-binding compounds impair Pseudomonas aeruginosa biofilm formation, especially under anaerobic conditions. Journal of Medical Microbiology 58 (Pt 6) (Jun): 765-73. doi:10.1099/jmm.0.004416-0
[11] L. Yang, K. B. Barken, M. E. Skindersoe, A. B. Christensen, M. Givskov, and T. Tolker-Nielsen. 2007. Effects of iron on DNA release and biofilm development by Pseudomonas aeruginosa. Microbiology (Reading, England) 153 (Pt 5) (May): 1318-28.
[12] F. Berlutti, ,C. Morea, A. Battistoni, S. Sarli, P. Cipriani, F. Superti, M. G. Ammendolia, and P. Valenti. 2005. Iron availability influences aggregation, biofilm, adhesion and invasion of Pseudomonas aeruginosa and Burkholderia cenocepacia. International Journal of Immunopathology and Pharmacology 18 (4) (Oct-Dec): 661-70.
[13] E.Banin, , M. L. Vasil, and E. P. Greenberg. 2005. Iron and Pseudomonas aeruginosa biofilm formation. Proceedings of the National Academy of Sciences of the United States of America 102 (31) (Aug 2): 11076-81.
[14] X. Chen, and P. S. Stewart. 2002. Role of electrostatic interactions in cohesion of bacterial biofilms. Applied Microbiology and Biotechnology 59 (6) (Sep): 718-20. doi:10.1007/s00253-002-1044-2
[15] Y. Ju-Nam, and J. R. Lead. 2008. Manufactured nanoparticles: An overview of their chemistry, interactions and potential environmental implications. The Science of the Total Environment 400 (1-3) 396-414. doi:10.1016/j.scitotenv.2008.06.042
[16] E. N.,Taylor, and T. J. Webster. 2009. The use of superparamagnetic nanoparticles for prosthetic biofilm prevention. International Journal of Nanomedicine 4 : 145-52.
[17] S. Ravikumar, R. Gokulakrishnan, K. Selvanathan, and S. Samayanan. 2011. Antibacterial activity of metal oxide nanoparticles against ophthalmic pathogens. International Journal of Pharmaceutical Research and Development 3 (5): 122-7.
[18] R. C. Moulton, and T. C. Montie. 1979. Chemotaxis by Pseudomonas aeruginosa. Journal of Bacteriology 137 (1) (Jan): 274-80.
[19] Young Soo Kang, , Subhash Risbud, John F. Rabolt, and Pieter Stroeve. 1996. Synthesis and characterization of nanometersize fe3O4 and γ-fe2O3 particles. Chemistry of Materials 8 (9)): 2209-2211.
[20] G. A. O'Toole, and R. Kolter. 1998. Initiation of biofilm formation in Pseudomonas fluorescens WCS365 proceeds via multiple, convergent signalling pathways: A genetic analysis. Molecular Microbiology 28 (3) (May): 449-61. doi:10.1046/j.1365-2958.1998.00797.x
[21] W. M. Huston, A. J. Potter, M. P. Jennings, J. Rello, A. R. Hauser, and A. G. McEwan. 2004. Survey of ferroxidase expression and siderophore production in clinical isolates of Pseudomonas aeruginosa. Journal of Clinical Microbiology 42 (6) (Jun): 2806-9. doi:10.1128/JCM.42.6.2806-2809.2004
[22] C. D. Cox, 1986. Role of pyocyanin in the acquisition of iron from transferrin. Infection and Immunity 52 (1) (Apr): 263-70.

comments powered by Disqus

Copyright © 2017 by authors and Scientific Research Publishing Inc.

Creative Commons License

This work and the related PDF file are licensed under a Creative Commons Attribution 4.0 International License.