title: Simultaneous monitoring of Staphylococcus aureus growth in a multi-parametric microfluidic platform using microscopy and impedance spectroscopy.
abstract: We describe the design, construction, and characterization of a scalable microfluidic platform that allows continuous monitoring of biofilm proliferation under shear stress conditions. Compared to other previous end-point assay studies, our platform offers the advantages of integration into multiple environments allowing simultaneous optical microscopy and impedance spectroscopy measurements. In this work we report a multi-parametric sensor that can monitor the growth and activity of a biofilm. This was possible by combining two interdigitated microelectrodes (IDuEs), and punctual electrodes to measure dissolved oxygen, K+, Na+ and pH. The IDuE has been optimized to permit sensitive and reliable impedance monitoring of Staphylococcus aureus V329 growth with two- and four-electrode measurements. We distinguished structural and morphological changes on intact cellular specimens using four-electrode data modeling. We also detected antibiotic mediated effects using impedance. Results were confirmed by scanning electrode microscopy and fluorescence microscopy after live/dead cell staining. The bacitracin mediated effects detected with impedance prove that the approach described can be used for guiding the development of novel anti-biofilm agents to better address bacterial infection.
authors.affiliation: Grup d'Enginyeria de Materials (GEMAT), Institut Químic de Sarrià, Universitat Ramon Llull, Spain.
authors.forename: O
authors.initials: O
authors.lastname: Estrada-Leypon
authors.affiliation: Instituto de Microelectrónica de Barcelona (IMB-CNM, CSIC), Bellaterra, Spain; Centro de Investigación Biomédica en Red, Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Zaragoza, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Moya
authors.affiliation: Instituto de Microelectrónica de Barcelona (IMB-CNM, CSIC), Bellaterra, Spain; Centro de Investigación Biomédica en Red, Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Zaragoza, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Guimera
authors.affiliation: Instituto de Microelectrónica de Barcelona (IMB-CNM, CSIC), Bellaterra, Spain; Centro de Investigación Biomédica en Red, Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Zaragoza, Spain.
authors.forename: G
authors.initials: G
authors.lastname: Gabriel
authors.affiliation: Grup d'Enginyeria Molecular (GEM), Institut Químic de Sarrià, Universitat Ramon Llull, Spain.
authors.forename: M
authors.initials: M
authors.lastname: Agut
authors.affiliation: Department of Neurology, Division of Neuromuscular Diseases, Beth Israel Deaconess Medical Center, 330 Brookline Avenue, Harvard Medical School, Boston, MA 02215-5491, USA.
authors.forename: B
authors.initials: B
authors.lastname: Sanchez
authors.affiliation: Grup d'Enginyeria de Materials (GEMAT), Institut Químic de Sarrià, Universitat Ramon Llull, Spain. Electronic address: salvador.borros@iqs.url.edu.
authors.forename: S
authors.initials: S
authors.lastname: Borros
mesh_terms: D018441:Biofilms; D017097:Electric Impedance; D008839:Microelectrodes; D044085:Microfluidics; D013057:Spectrum Analysis / Q000379:methods*; D013211:Staphylococcus aureus / Q000254:growth & development*
keywords: Bacitracin; Biofilm; Impedance spectroscopy; Interdigitated microelectrodes; Microfluidic device