Magdalena Plotka
University of Gdansk, Faculty of Biology
Department of Microbiology
Magdalena Plotka is an Associate Professor and head of the Department of Microbiology at the Faculty of Biology, University of Gdansk (Poland). In 2025, she was also appointed Head of the Plasmid and Microorganism Collection at the same faculty. The research interests of her group focus on practical application of endolysins especially derived from bacteriophages existing in extreme environments. She is also actively involved in studies of protein structure-function relationships and antibacterial peptides derived from lysins functional domains, which hold promise as alternative therapeutics against multidrug-resistant bacteria. She is a co-founder of the Polish Society for the Study of Viruses and Microorganisms.
Affiliations: (1). Department of Microbiology, Faculty of Biology, University of Gdansk, Wita Stwosza (59), (80)-(308), Gdansk (Poland)
Studies on endolysins derived from thermophilic bacteriophages, although important for e.g. the protein’s stability point of view, are still limited. This may be due to difficulties in accessing sites where thermophages occur, e.g. hot springs or hydrothermal vents, or difficulties in culturing extremophiles in laboratory conditions. We successfully analyzed three extremophilic type 2 amidases, one type 3 amidase, and one endopeptidase focusing on structure-function relationship. We also analyzed a number of mesophilic proteins that are structurally similar to the thermophilic endolysins. Although the temperature optimum for activity of extremophilic endolysins is around 60 °C, the proteins are also active against mesophiles at lower temperatures. MIC values have been determined for clinical strains of bacteria including Pseudomonas aeruginosa and carbapenem-resistant Acinetobacter baumannii. The activity of lysins against forming/mature biofilms and persister cells was also assessed. Although in vitro studies are very promising and have shown, for example, the elimination of 107 bacteria exposed to endolysins, in vivo studies are much more challenging. We observe inactivation of endolysins in the presence of human serum as well as their weak activity in in vivo models such as Galleria mellonella. We would like to discuss these aspects of endolysin activity during The Phage Protein Meeting.