Bacteriophages as potential tools to combat pathogenic bacteria

Abstract text (incl. figure legends and references)

Biofilms are biological systems that consist of microbial communities embedded in a polysaccharide layer. Bacteria living within biofilms tend to develop antibiotic resistance and are difficult to combat [1]. Bacteriophages are specific to bacteria that they infect and are harmless to human cells [2]. Therefore, they can be applied to fight bacterial infections caused by biofilm formers [3].

The aim was to prepare and characterize MS2 phages and apply them in preliminary studies with host bacteria (E. coli) in comparison with their action on eukaryotic cells.

MS2 phages were propagated, filtered and purified by ultracentrifugation in CsCl. The purity of the phage samples was evaluated by SDS-PAGE and the identification of the phage proteins was performed by Western blotting. The plaque assay and spot test were used to quantify phage bioactivity and determine phage titers, whereas virus concentration was quantified by UV-Vis spectrophotometry. The spherical morphology and the integrity of the MS2 phages were confirmed by SEM. E. coli as well as eukaryotic cells (HeLa) were subjected to phages to assess their biological effect.

The bacteriophages were viable and acted antibacterial against E. coli cells. In contrast, they did not harm HeLa cells.

MS2 phages can be selectively applied against E. coli bacteria while being harmless for HeLa cells. Thus, a phage therapy is a potential option to combat bacterial infections.

[1] A. Penesyan, I. T. Paulsen, S. Kjelleberg, M. R. Gillings, Three faces of biofilms: a microbial lifestyle, a nascent multicellular organism, and an incubator for diversity. npj Biofilms and Microbiomes 7(1) (2021) 80.

[2] M. Popescu, J. D. Van Belleghem, A. Khosravi, P. L. Bollyky, Bacteriophages and the immune system, Annual Review of Virology 8, (2021) 415-435.

[3] S. Liu, H. Lu, S. Zhang, Y. Shi, Q. Chen, Phages against pathogenic bacterial biofilms and biofilm-based infections: a review, Pharmaceutics 14 (2022) 427.