A Real-Time Thermal Sensor System for Quantifying the Inhibitory Effect of Antimicrobial Peptides on Bacterial Adhesion and Biofilm Formation

Abstract

The increasing rate of antimicrobial resistance (AMR) in pathogenic bacteria is a global threat to human and veterinary medicine. Beyond antibiotics, antimicrobial peptides (AMPs) might be an alternative to inhibit the growth of bacteria, including AMR pathogens, on different surfaces. Biofilm formation, which starts out as bacterial adhesion, poses additional challenges for antibiotics targeting bacterial cells. The objective of this study was to establish a real-time method for the monitoring of the inhibition of (a) bacterial adhesion to a defined substrate and (b) biofilm formation by AMPs using an innovative thermal sensor. We provide evidence that the thermal sensor enables continuous monitoring of the effect of two potent AMPs, protamine and OH-CATH-30, on surface colonization of bovine mastitis-associated Escherichia (E.) coli and Staphylococcus (S.) aureus. The bacteria were grown under static conditions on the surface of the sensor membrane, on which temperature oscillations generated by a heater structure were detected by an amorphous germanium thermistor. Bacterial adhesion, which was confirmed by white light interferometry, caused a detectable amplitude change and phase shift. To our knowledge, the thermal measurement system has never been used to assess the effect of AMPs on bacterial adhesion in real time before. The system could be used to screen and evaluate bacterial adhesion inhibition of both known and novel AMPs.

A Comprehensive Review of Recent Research into the Effects of Antimicrobial Peptides on Biofilms—January 2020 to September 2023

“…Seven publications were assigned to the 'Miscellaneous' category, including publications relating to the optimization of AMPs (L5K5W, S6L3-33, bactenecin, and DASamP1) against biocorrosive bacteria [139], marine-based AMPs [140], and a real time thermal sensor for quantifying the inhibitory effects of AMPs (protamine and OH-CATH-30) on biofilms and bacterial adhesion [141]. A comment relating to the AMP cecropin A, derived from moths, was made by Fenner [142].…”

Preventing Biofilm Formation and Development on Ear, Nose and Throat Medical Devices

“…Various types of antibiotic substances are available now with bactericidal or bacteriostatic effects, but the availability and massive use enhanced the discerning pressure on bacteria [57,58]. Therefore, antimicrobial resistance (AMR) had a growth in time for pathogenic bacteria resulting in a potentially fatal outcome [59,60].…”

Sensor system for analysis of biofilm sensitivity to ampicillin

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