Functionalized polyanilines disrupt Pseudomonas aeruginosa and Staphylococcus aureus biofilms.
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 20 mgml(-1). Surprisingly, we discovered that the same concentration (20 mgml(-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.
School of Chemical Sciences, the University of Auckland, Private Bag 92019, Auckland Mail Centre, Auckland 1142, New Zealand. Electronic address: m.gizdavic@auckland.ac.nz.
Marija R
MR
Gizdavic-Nikolaidis
School of Medicine, University of Tasmania, Hobart 7001, Tasmania, Australia.
Joanne C
JC
Pagnon
School of Medicine, University of Tasmania, Hobart 7001, Tasmania, Australia.
Naseem
N
Ali
School of Medicine, University of Tasmania, Hobart 7001, Tasmania, Australia.
Reuben
R
Sum
Central Science Laboratory, University of Tasmania, Hobart 7001, Tasmania, Australia.
Noel
N
Davies
School of Medicine, University of Tasmania, Hobart 7001, Tasmania, Australia.
Louise F
LF
Roddam
School of Medicine, University of Tasmania, Hobart 7001, Tasmania, Australia. Electronic address: Mark.Ambrose@utas.edu.au.
Mark
M
Ambrose
D000814:Aniline Compounds / Q000737:chemistry / Q000494:pharmacology*; D018441:Biofilms; D008826:Microbial Sensitivity Tests; D008856:Microscopy, Fluorescence; D011550:Pseudomonas aeruginosa / Q000187:drug effects*; D053038:Quorum Sensing; D013056:Spectrophotometry, Ultraviolet; D017550:Spectroscopy, Fourier Transform Infrared; D013211:Staphylococcus aureus / Q000187:drug effects*
D000814:Aniline Compounds; C416807:polyaniline
Biofilms; Functionalized polyanilines; Pseudomonas aeruginosa; Staphylococcus aureus; Stationary phase