Abstract
BACKGROUND: Difficult-to-treat bacterial infections represent a significant public health issue.(1) Phage therapy is emerging as a promising strategy to be combined with antibiotic treatment for their eradication.(2) In Italy, the demand for this therapy is steadily increasing; however, patients can receive phage therapy only under compassionate use (approval by an Ethics Committee (EC)).(3) METHODS: From January 1, 2021, to September 30, 2024, 47 patients contacted the Bacteriophage Laboratory at the University of Pisa requesting phage therapy. Of these, only 22 patients (46.8%) were supported by a specific request from a specialist physician. RESULTS: The chronic infections to be treated were mainly osteoarticular (n = 8, 36%) and respiratory tract infections (n = 6, 27.27%), followed by soft tissue and cardiovascular infections (n = 3, 13.64% each), post-surgical and abdominal infections (n = 1, 4.55% each). In total, 39 bacterial strains of different species were received: P. aeruginosa (n = 19, 48.7%), S. aureus (n = 5, 12.8%), Achromobacter spp. (n = 3, 7.69%), P. mirabilis, A. baumannii, K. pneumoniae (n = 2, 5.13% each), E. coli, S. pyogenes, S. maltophilia, E. hormachaei, E. faecalis, M. arupense (n = 1, 2.56% each). Each strain was tested for susceptibility to bacteriophages in the Phage Bank (PB). In cases of a positive results, the lytic activity was evaluated using a phagogram, along with the synergistic activity with antibiotics (based on the antibiogram of the tested strain). No phages from the PB were active against only 7 bacterial strains (18%); however, research for specific bacteriophages is ongoing. Among the 17 patients eligible for phage therapy, a personalized treatment protocol has been defined for two cases, and a request for compassionate use has been submitted to the EC. CONCLUSIONS: Although phage therapy currently requires EC approval, slowing down the patient treatment process, our experience is laying the foundation for defining a phage-based therapeutic approach within the precision medicine framework.