Phage therapy has a long-standing history in Eastern Europe. In the West, since 2007 the group at the Queen Astrid Military Hospital (QAMH) in Belgium has been treating patients with phage therapy utilizing protocols based on the experiences of the George Eliava Institute of Bacteriophages. A retrospective analysis was performed on a 100 of these cases which included an assessment of phage-resistant bacteria isolated from some of these patient cases. We received 21 isolates from 5 patient cases with varied infections, but all caused by the pathogen Pseudomonas aeruginosa. Whole genome sequencing was performed on these isolates combining Illumina (long-read) and Nanopore (short read) technology in order to determine single-nucleotide polymorphisms (SNP). Analysis of sequencing results show changes in phage-resistant isolates recovered from patients correlates with changes in known phage receptors. For one case in particular we see changes associated with resensitivity of pan-resistant bacteria to antibiotics which was demonstrated in patient antibiogram results. This works adds to further evidence that combined phage and antibiotic therapy can be a successful strategy to treat patients with resistant or difficult-to-treat infections.