The treatment of infections caused by Staphylococcus aureus faces a serious threat today – growing antibiotic resistance. A team led by Zdeněk Farka from Masaryk University in Brno, in collaboration with Hana Lísalová's team from the Division of Optics of the Institute of Physics of the Czech Academy of Sciences, is therefore looking for new ways to faster and more effective evaluation of the so-called phage therapies, which could offer an alternative to traditional antibiotics. A key role in this research is played by biosensors, which enable real-time monitoring of bacterial response. The research results were published in the journal Scientific Reports.
In their recently published study, the research teams present a new biosensor approach based on QCM-D (Quartz Crystal Microbalance with Dissipation Monitoring) technology, which allows real-time observation of how bacteria respond to the action of bacteriophages or their combination with antibiotics. Compared to traditional cultivation methods, which take hours or even days, the biosensor provides immediate information on whether bacteria are actively growing or disintegrating as a result of drug action.
"Our results show that QCM-D biosensor technology can be a powerful tool in the development of new therapies. It allows us to quickly and accurately evaluate how different substances affect bacteria," summarizes Hana Lísalová, head of the Laboratory of Functional Biointerfaces.
A new study shows that the QCM-D method can be used to monitor bacterial lysis in real time. This allows scientists to observe almost immediately how bacteria respond to phage particles, without having to wait long for the results of culture tests. The technology also makes it possible to distinguish whether bacteria are actively growing or disintegrating as a result of the action of bound agents. A particularly beneficial discovery is the confirmation of the synergistic effect between bacteriophage P68, a virus that attacks and breaks down bacteria (known as a lytic phage), and the antibiotic amoxicillin – this combination prevents bacteria from clumping together and increases the effectiveness of treatment.
"Biosensors are now used in a wide range of areas, from medicine to the environment to industry. This research is a fine example of how cooperation between research institutions can yield concrete and practical results," adds Alexandr Dejneka, head of the Division of Optics at the Institute of Physics of the Czech Academy of Sciences.
The developed method has great potential for the future – not only for basic research into biofilms and bacterial resistance mechanisms, but also for rapid testing of the effectiveness of various phages, antibiotics, and their combinations directly on clinical samples. Combining the low cost of sensors, the possibility of automation, and rapid interpretation of results, this technology can become a useful tool in clinical practice and in the development of new treatments.
Schématické znázornění průběhu experimentu na povrchu senzoru QCM-D.
(A) Sledování lýzy bakterií působením lysostaphinu s detailem štěpení pentaglycinového můstku bakteriálního peptidoglykanu.
(B) Fágem zprostředkovaná lýza na senzoru s detailem lytického cyklu fága v bakterii.