Synergistic antimicrobial effect against early biofilm formation: micropatterned surface plus antibiotic treatment

• Published in: International journal of antimicrobial agents 2012-09, Vol.40 (3), p.221-226
• Main Authors: Díaz, C, Miñán, A, Schilardi, P.L, Fernández Lorenzo de Mele, M
• Format: Article
• Language: English
• Subjects: adhesion; Anti-Bacterial Agents - pharmacology; anti-infective properties; antibiotic resistance; Antibiotics. Antiinfectious agents. Antiparasitic agents; Antimicrobial resistance; bacteria; Bacterial adhesion; Bacterial Adhesion - drug effects; bacterial colonization; Bacterial Load; biofilm; Biofilms - drug effects; Biofilms - growth & development; Biological and medical sciences; Drug Synergism; gold; Gold - pharmacology; Infectious Disease; Medical sciences; Microbial Sensitivity Tests; minimum inhibitory concentration; Patterned surface; Pharmacology. Drug treatments; Pseudomonas; Pseudomonas fluorescens; Pseudomonas fluorescens - drug effects; Pseudomonas fluorescens - growth & development; Pseudomonas fluorescens - physiology; streptomycin; Streptomycin - pharmacology; Surface Properties; synergism; Synergy
• ISSN: 0924-8579; 1872-7913
• DOI: 10.1016/j.ijantimicag.2012.05.012

The detrimental effects of biofilms are a cause of great concern in medical, industrial and environmental areas. In this study, we proposed a novel eradication strategy consisting of the combined use of micropatterned surfaces and antibiotics on biofilms to reduce the rate of bacterial colonisation. Pseudomonas fluorescens biofilms were used to perform a comparative evaluation of possible strategies to eradicate these biological layers. First, the minimum inhibitory concentration (MIC) and minimum bactericidal concentration of planktonic cultures were determined. Subsequently, adhesion of bacteria on microstructured gold surfaces (MS) with patterned features that were similar to the bacterial diameter as well as on smooth nanostructured gold (NS) was assessed. As expected, lower bacterial attachment as well as inhibition of bacterial aggregation were observed on MS. The effect of streptomycin treatment (ST) in the concentration range 1–4mg/L (0.25–1× MIC) on biofilms grown on MS and NS was also evaluated. The combined strategy involving the use of micropatterned surfaces and antibiotic treatment (MS+ST) to eradicate Pseudomonas biofilms was then investigated. Results showed a synergistic effect of MS+ST that yielded a reduction of ≥1000-fold in the number of surviving biofilm bacteria with respect to those obtained with single ST or MS. The combined strategy may be a significant contribution to the eradication of biofilms from different environments. In addition, the important role of early monolayer bacterial aggregates in increasing resistance to antimicrobial agents was demonstrated.