Current status of bacteriophage therapy for severe bacterial infections.

The increase in the incidence of antibiotic-resistant bacteria poses a global public health threat. According to a 2019 WHO report, approximately 1.27 million deaths were attributed to antibiotic-resistant bacteria, with many cases linked to specific bacterial species, such as drug-resistant Pseudomonas aeruginosa and Staphylococcus aureus. By 2050, the number of deaths caused by these bacteria is predicted to surpass that caused by cancer. In response to this serious situation, phage therapy, an alternative to antibiotic treatment, has gained attention. Phage therapy involves the use of viruses that target specific bacteria to treat infections. This method has proven effective in multiple clinical cases, particularly for patients with severe infections caused by multidrug-resistant bacteria. For example, there are reports of patients with systemic infections caused by multidrug-resistant Acinetobacter who recovered following phage administration and patients infected with panresistant Pseudomonas aeruginosa who were cured by phage therapy. A key feature of phage therapy is its high specificity. Phages infect only specific bacteria and eliminate them. However, this specificity can also be a disadvantage, as careful selection of the appropriate phage for the target bacteria is needed. Additionally, bacteria can develop resistance to phages, potentially reducing treatment effectiveness over time. Efforts are underway to select, combine, and improve phages to address these challenges. In Belgium, a national phage bank has been established, and in the United States, the University of California, San Diego, has founded Innovative Phage Applications and Therapeutics (IPATH), marking significant progress toward the clinical application of phage therapy in the country. As a result, phage therapy is emerging as a component of personalized medicine, offering a new treatment option against antibiotic-resistant bacteria. The clinical application of phage therapy is particularly important in life-saving treatments for patients with severe bacterial infections, and its use in conjunction with antibiotics could enhance therapeutic outcomes. Continued research and development of this therapy could provide hope for many more patients in the future.