The Application of Impedance Spectroscopy for Pseudomonas Biofilm Monitoring during Phage Infection

• Published in: Viruses Vol. 12; no. 4; p. 407
• Main Authors: Guła, Grzegorz, Szymanowska, Paulina, Piasecki, Tomasz, Góras, Sylwia, Gotszalk, Teodor, Drulis-Kawa, Zuzanna
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 07.04.2020; MDPI
• Subjects: Antibiotics; Bacteria; Bacteriophages; biofilm; Biofilms; Biofilms - growth & development; Cell culture; Conductance; Culture Media; Dielectric Spectroscopy - methods; Dilution; Experiments; Extracellular Polymeric Substance Matrix - physiology; Growth; Health aspects; Impedance spectroscopy; Measurement techniques; Methods; Microbial mats; Microscopy; phage LUZ19; Phages; Physiological aspects; Polymers; Pseudomonas; Pseudomonas aeruginosa; Pseudomonas aeruginosa - physiology; Pseudomonas aeruginosa - virology; Pseudomonas Phages - physiology; quartz tuning forks; Sensors; Spectroscopy; Spectrum analysis; Poland; United States > US; Pseudomonas aeruginosa; impedance spectroscopy; phage LUZ19; quartz tuning forks; biofilm
• ISSN: 1999-4915; 1999-4915
• DOI: 10.3390/v12040407

Bacterial biofilm prevention and eradication are common treatment problems, hence there is a need for advanced and precise experimental methods for its monitoring. Bacterial resistance to antibiotics has resulted in an interest in using a natural bacterial enemy-bacteriophages. In this study, we present the application of quartz tuning forks (QTF) as impedance sensors to determine in real-time the direct changes in PAO1 biofilm growth dynamics during phage LUZ 19 treatment at different multiplicities of infection (MOI). The impedance of the electric equivalent circuit (EEC) allowed us to measure the series resistance (Rs) corresponding to the growth-medium resistance (planktonic culture changes) and the conductance (G) corresponding to the level of QTF sensor surface coverage by bacterial cells and the extracellular polymer structure (EPS) matrix. It was shown that phage impacts on sessile cells (G dynamics) was very similar in the 10-day biofilm development regardless of applied MOI (0.1, 1 or 10). The application of phages at an early stage (at the sixth h) and on three-day biofilm caused a significant slowdown in biofilm dynamics, whereas the two-day biofilm turned out to be insensitive to phage infection. We observed an inhibitory effect of phage infection on the planktonic culture (Rs dynamics) regardless of the MOI applied and the time point of infection. Moreover, the Rs parameter made it possible to detect PAO1 population regrowth at the latest time points of incubation. The number of phage-insensitive forms reached the level of untreated culture at around the sixth day of infection. We conclude that the proposed impedance spectroscopy technique can be used to measure the physiological changes in the biofilm matrix composition, as well as the condition of planktonic cultures in order to evaluate the activity of anti-biofilm compounds.