Nanomechanical detection of Escherichia coli infection by bacteriophage T7 using cantilever sensors

• Published in: Nanoscale Vol. 11; no. 38; pp. 17689 - 17698
• Main Authors: Mertens, Johann, Cuervo, Ana, Carrascosa, José L
• Format: Journal Article
• Language: English
• Published: England Royal Society of Chemistry 03.10.2019
• Subjects: Antibiotics; Bacteria; Bacterial diseases; Bacteriophage T7 - metabolism; Biosensing Techniques; E coli; Escherichia coli - virology; Phages; Reagents; Variation; Viability; Viruses
• ISSN: 2040-3364; 2040-3372
• DOI: 10.1039/c9nr05240b

Viruses that infect bacteria (bacteriophages) are a promising alternative treatment for bacterial diseases, especially in the case of antibiotic resistance. Due to a renewed interest in phage therapies, development of rapid and specific detection methods for bacteria/bacteriophage interaction are gaining attention for proper diagnosis and treatment. This paper describes a new method to detect the interaction between Escherichia coli and bacteriophage T7 in a sensitive and quantitative way, using the nanomechanical motion of bacteria adhered to a cantilever surface. Our approach combines both deflection and dynamic frequency-domain characterization. The device was able to determine the viability of a low amount of living bacteria attached to the cantilever, and was used to monitor T7 interaction with E. coli over a wide range of virus concentrations up to 109 PFU ml-1. The nanomechanical assay described here requires no protein labeling and can be performed in a single reaction without additional reagents. The system was able to detect the interaction between a few thousand particles through the fluctuation of mechanical energy over a broad range of frequencies. The presented data provides the basis for more detailed studies of the sequence of molecular events that contribute to the motion of the device.