Bacterial infections of different tissues and organs that prove incurable by antibiotics are a serious clinical problem. Bacteriophages (phages) are bacterial viruses which attack, multiply within, and then destroy bacteria. They can efficiently destroy bacteria which have acquired resistance to antibiotics and which cause life-threatening infections. The method of treating bacterial infections using phages has been known since the beginning of the 20th century. This experimental treatment enables the use of phage preparations under the rules of a therapeutic experiment (on the basis of the respective Polish regulations) in cases where no effective available therapy exists or the use of the targeted drug is contraindicated. It is not a research study.