Case 42

Patient 42 is a 41 year-old female patient who underwent plastic surgical care for over 7 years. 15 years prior she had an injection of industrial silicone oil to her buttocks and lower back as part of her gender reassignment procedures. In the previous 7 years, she suffered multiple infections of the affected regions and underwent multiple long hospitalizations to treat and control these infections. Multiple debridements, local wound care, systemic antibiotic treatments and wound closures with flaps and skin grafts were required. It was not possible to truly debride the tissue since the silicone oil was diffusely infiltrated in muscles involving the thigh, gluteus maximus and lower back; most of the soft tissue of the gluteal and thigh regions had been previously debrided. Her previous infections were due to Pseudomonas aeruginosa which became resistant to all antibiotic treatments over time. Six different morphotypes were collected over the course of 6 months all with different antimicrobial susceptibility patterns. Sensitivity testing suggested synergy between a combination of P. aeruginosa bacteriophage and meropenem against these six isolates which were all present at the start of phage therapy. The patient completed 17 days of IV phage BID and had local debridement QD along with a single P. aeruginosa bacteriophage at a titer of (1×1011 PFU/dose) and meropenem. Wound improvement and reduction of pain was noted on 01Feb2021 and granulation tissue was noted with reduced secretions on 09Feb2021. The first course of therapy ended on the 10th of February. With continued wound improvement post therapy, the patient received another debridement on 25Feb2021. However, by 28Feb2021 increased secretions were observed at the surgical site and additional phage were requested. An additional 8 vials were provided to continue therapy. The second course of treatment is ongoing; the patient has completed 14 days of IV phage BID and locally QD at a titer of 1×1010 PFU/dose.