Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas, Facultad de Ciencias Exactas, Universidad Nacional de La Plata-CCT La Plata, CONICET, Casilla de Correo 16, Sucursal 4, 1900 La Plata, Argentina.
Int J Antimicrob Agents. 2012 Sep;40(3):221-6. doi: 10.1016/j.ijantimicag.2012.05.012. Epub 2012 Jul 15.
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 1-4 mg/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.
生物膜的有害影响是医学、工业和环境领域非常关注的问题。在这项研究中，我们提出了一种新的消除策略，包括联合使用微图案表面和抗生素来消除生物膜，以降低细菌定植的速度。使用荧光假单胞菌生物膜对可能的消除这些生物层的策略进行了比较评估。首先，确定了浮游培养物的最小抑菌浓度 (MIC) 和最小杀菌浓度。随后，评估了具有类似于细菌直径的图案特征的微结构化金表面 (MS) 和光滑纳米结构化金 (NS) 上细菌的粘附。如预期的那样，在 MS 上观察到较低的细菌附着和抑制细菌聚集。还评估了浓度范围为 1-4 mg/L（0.25-1×MIC）的链霉素处理 (ST) 对 MS 和 NS 上生长的生物膜的影响。然后研究了涉及使用微图案表面和抗生素处理 (MS+ST) 来消除铜绿假单胞菌生物膜的联合策略。结果表明，MS+ST 具有协同作用，与单独使用 ST 或 MS 相比，存活的生物膜细菌数量减少了≥1000 倍。该联合策略可能对消除来自不同环境的生物膜有重要贡献。此外，还证明了早期单层细菌聚集体在增加对抗菌剂的抗性方面的重要作用。
