Polyethyleneimine and polyethyleneimine-based nanoparticles: novel bacterial and yeast biofilm inhibitors

• Type: Article in International Scientific Journal
• Date: 2014

Authors

Azevedo, MM (Author) Other; Ramalho, P (Author) Other; Silva, AP (Author) Other; Teixeira Santos, R (Author) FMUP; pina-vaz, c (Author) FMUP; rodrigues, ag (Author) FMUP

Journal

Title: Journal of Medical Microbiology

Vol. 63

Pages: 1167-1173

ISSN: 0022-2615

Publisher: Microbiology Society

Indexing

ISI Web of Knowledge - 47 Citations

Scopus - 47 Citations

Other information

Authenticus ID: P-009-S9X

DOI: 10.1099/jmm.0.069609-0

Abstract (EN): Biofilms are commonly involved in medical device-related infections. The purpose of this study was to determine the antimicrobial and anti-biofilm activity of polyethyleneimine (PEI) and PEI-based nanoparticles (nanoPEI) against Staphylococcus aureus, Staphylococcus epidermidis, Acinetobacter baumannii and Candida albicans (clinical and ATCC strains), and to evaluate their effect upon biofilm formation on polyurethane (PUR)-like catheters. MICs and minimal lethal concentrations of PEI and nanoPEI were determined according to CLSI microdilution reference protocols. For PEI, the MIC value was 195.31 mg l(-1) for all the bacteria and 48.83 mg l(-1) for the yeast strains. For nanoPEI, the MIC value was 1250 mg l(-1) for all the strains except A. baumannii, for which it was 2500 mg l(-1). Biofilm formation was assessed with FUR-like catheter segments and biofilm metabolic activity was quantified by colorimetry with a tetrazolium reduction assay. Plasma membrane integrity and membrane potential were assessed by flow cytometty after staining microbial cells with a membrane-impermeable dye, propidium iodide, and a membrane-potential marker, DiBAC(4)(3). PEI inhibited growth of all microbial species; higher concentrations of nanoPEI were needed to inhibit growth of all species. Biofilm formation in the presence of antibacterial PEI activity was dose-dependent (except for S. epidermidis) and species-related. NanoPEI at 0.5xMIC and MIC significantly reduced the metabolic activity of biofilms of S. aureus, S. epidermidis and A. baumannii, whereas 2xMIC was required in order to inhibit biofilm metabolic activity.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 7