Combining bacteriophages with cefiderocol and meropenem/vaborbactam to treat a pan-drug resistant Achromobacter species infection in a pediatric cystic fibrosis patient.

Cystic fibrosis is associated with significant morbidity and early mortality due to recurrent acute and chronic lung infections. The chronic use of multiple antibiotics without pathogen eradication increases the possibility of extensive drug resistance or even pan-drug resistance (PDR). It is imperative that new or alternative treatment options be explored. We present a clinical case of a 10-year-old female cystic fibrosis patient, infected with a PDR Achromobacter spp. She was treated with cefiderocol, meropenem/vaborbactam, and bacteriophage therapy (Ax2CJ45ϕ2) during two separate admissions in an attempt to clear her infection and restore baseline pulmonary function. The Centers for Disease Control and Prevention confirmed antibiotic susceptibilities, which showed resistance to both cefiderocol and meropenem/vaborbactam. However, after using all three agents concomitantly during the second treatment course, our patient's pulmonary function improved dramatically, and the Achromobacter spp. could not be isolated from sputum samples obtained 8 and 16 weeks after completion of therapy. Overall, the treatment regimen consisting of cefiderocol, meropenem/vaborbactam, and bacteriophage was safe and well-tolerated in our patient.

Early clinical experience of bacteriophage therapy in 3 lung transplant recipients.

Bacteriophage therapy (BT) uses bacteriophages to treat pathogenic bacteria and is an emerging strategy against multidrug-resistant (MDR) infections. Experience in solid organ transplant is limited. We describe BT in 3 lung transplant recipients (LTR) with life-threatening MDR infections caused by Pseudomonas aeruginosa (n = 2) and Burkholderia dolosa (n = 1). For each patient, lytic bacteriophages were selected against their bacterial isolates. BT was administered for variable durations under emergency Investigational New Drug applications and with patient informed consent. Safety was assessed using clinical/laboratory parameters and observed clinical improvements described, as appropriate. All patients received concurrent antibiotics. Two ventilator-dependent LTR with large airway complications and refractory MDR P. aeruginosa pneumonia received BT. Both responded clinically and were discharged from the hospital off ventilator support. A third patient had recurrent B. dolosa infection following transplant. Following BT initiation, consolidative opacities improved and ventilator weaning was begun. However, infection relapsed on BT and the patient died. No BT-related adverse events were identified in the 3 cases. BT was well tolerated and associated with clinical improvement in LTRs with MDR bacterial infection not responsive to antibiotics alone. BT may be a viable adjunct to antibiotics for patients with MDR infections.