title: Pseudomonas aeruginosa can be detected in a polymicrobial competition model using impedance spectroscopy with a novel biosensor.
abstract: Electrochemical Impedance Spectroscopy (EIS) is a powerful technique that can be used to elicit information about an electrode interface. In this article, we highlight six principal processes by which the presence of microorganisms can affect impedance and show how one of these--the production of electroactive metabolites--changes the impedance signature of culture media containing Pseudomonas aeruginosa. EIS, was used in conjunction with a low cost screen printed carbon sensor to detect the presence of P. aeruginosa when grown in isolation or as part of a polymicrobial infection with Staphylococcus aureus. By comparing the electrode to a starting measurement, we were able to identify an impedance signature characteristic of P. aeruginosa. Furthermore, we are able to show that one of the changes in the impedance signature is due to pyocyanin and associated phenazine compounds. The findings of this study indicate that it might be possible to develop a low cost sensor for the detection of P. aeruginosa in important point of care diagnostic applications. In particular, we suggest that a development of the device described here could be used in a polymicrobial clinical sample such as sputum from a CF patient to detect P. aeruginosa.
authors.affiliation: Department of Biomedical Engineering, University of Strathclyde, Glasgow, United Kingdom.
authors.forename: Andrew C
authors.initials: AC
authors.lastname: Ward
authors.affiliation: Department of Biomedical Engineering, University of Strathclyde, Glasgow, United Kingdom.
authors.forename: Patricia
authors.initials: P
authors.lastname: Connolly
authors.affiliation: Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow, United Kingdom.
authors.forename: Nicholas P
authors.initials: NP
authors.lastname: Tucker
mesh_terms: D001422:Bacterial Adhesion / Q000187:drug effects; D015374:Biosensing Techniques / Q000379:methods*; D002452:Cell Count; D018920:Coculture Techniques; D058266:Dielectric Spectroscopy / Q000379:methods*; D004566:Electrodes; D056265:Microbial Interactions / Q000187:drug effects; D008954:Models, Biological; D009154:Mutation / Q000235:genetics; D010933:Plankton / Q000166:cytology; D011550:Pseudomonas aeruginosa / Q000302:isolation & purification*; D011710:Pyocyanine / Q000494:pharmacology; D013056:Spectrophotometry, Ultraviolet; D013211:Staphylococcus aureus / Q000254:growth & development
chemical_list: D011710:Pyocyanine