The purpose of the present study was to investigate the antimicrobial effects of functionalized polyanilines (fPANIs) against stationary phase cells and biofilms of Pseudomonas aeruginosa and Staphylococcus aureus using homopolymer of sulfanilic acid (poly-SO₃H) as a model. The chemically synthesized poly-SO₃H was characterized using Fourier Transform Infra-Red (FTIR) and Ultraviolet-Visible (UV-Vis) spectroscopies. The molecular weight (Mw) and elemental analysis of homopolymer poly-SO₃H were also examined. We found that poly-SO₃H was bactericidal against stationary phase cells of P. aeruginosa and S. aureus at a concentration of 20mgml-1. Surprisingly, we discovered that the same concentration (20mgml-1) of poly-SO₃H significantly disrupted and killed bacterial cells present in pre-established forty-eight hour static biofilms of these organisms, as shown by crystal violet and bacterial live/dead fluorescence staining assays. In support of these data, poly-SO₃H extensively diminished the expression of bacterial genes related to biofilm formation in stationary phase cells of P. aeruginosa, and seemed to greatly reduce the amount of the quorum sensing molecule N-(3-oxododecanoyl)-l-homoserine lactone (3OC₁₂-HSL) able to be recovered from biofilms of this organism. Furthermore, we found that poly-SO₃H was able to effectively penetrate and kill cells in biofilms formed by the P. aeruginosa (AESIII) isolate derived from the sputum of a cystic fibrosis patient. Taken together, the results of the present study emphasise the broad antimicrobial activities of fPANI, and suggest that they could be developed further and used in some novel ways to construct medical devices and/or industrial equipment that are refractory to colonization by biofilm-forming bacteria.

Item Type:	Refereed Article
Keywords:	Pseudomonas aeruginosa, Staphylococcus aureus, stationary phase, biofilms, functionalized polyanilines
Research Division:	Biomedical and Clinical Sciences
Research Group:	Medical microbiology
Research Field:	Medical bacteriology
Objective Division:	Health
Objective Group:	Clinical health
Objective Field:	Clinical health not elsewhere classified
UTAS Author:	Pagnon, JC (Dr Joanne Pagnon)
UTAS Author:	Ali, N (Mr Naseem Ali)
UTAS Author:	Sum, R (Mr Reuben Sum)
UTAS Author:	Davies, N (Associate Professor Noel Davies)
UTAS Author:	Roddam, LF (Dr Louise Roddam)
UTAS Author:	Ambrose, M (Dr Mark Ambrose)
ID Code:	105298
Year Published:	2015
Web of Science® Times Cited:	20
Deposited By:	Medicine
Deposited On:	2015-12-18
Last Modified:	2017-11-07
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