APPLICATIONS OF COMMERCIAL PHAGE PREPARATIONS (BACTERIOPHAGES) AGAINST ANTIBIOTIC RESISTANT BACTERIAL ISOLATES IN BULGARIA
Keywords:
bacteriophages, commercial phage preparation, phage therapyAbstract
Bacteriophages (from the Ancient-Greek word phagos (φάγος) – "devouring, eating") are viruses that can selectively kill bacteria. These viruses are found everywhere around us, in soils, rivers, oceans and even in the gastrointestinal tract of living organisms. They were discovered more than 100 years ago, but after the introduction of antibiotics, the research interest in them was lost. With the increase in antibiotic resistance, scientific research on bacteriophages has intensified in the direction of developing medical products containing selected phage cocktails. However, there is currently a lack of comparative or clinical trials in the field of phage therapy in Bulgaria. Some countries are adopting this type of treatment, while others are only considering their regulation. This study aims to develop an algorithm for the initial study of the effect of using a commercially available phage preparation, with a view to using it as a model for follow-up. Thirty-eight clinically relevant bacterial isolates from hospitalized and outpatient patients, which demonstrated antimicrobial resistance to strategic antibiotics for the treatment of the respective infections, were selected and studied. Twelve additional Escherichia coli strains isolated from food products were added. The results showed that the bacteriophages used were effective only against some of the tested bacterial strains (Pseudomonas aeruginosa, Escherichia coli and Streptococcus pyogenes). In addition, the lack of cytotoxic effect measured on mesenchymal stem cells was demonstrated, as well as stability during storage and reuse of the phage cocktail. Given the wide variety and availability of phage preparations, these cocktails must be determined strictly individually on an already isolated bacterial strain. Only in this way, a possible therapeutic approach using bacteriophages would lead to the desired antibacterial result.
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Copyright (c) 2026 N. Kalvatchev, I. Tsekov, I. Sirakov, A. Stratev, Y. Kizheva, R. Gergova, T. Strateva (Author)
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