Cefiderocol for the treatment of difficult-to-treat resistance in Pseudomonas aeruginosa ventriculitis

Purpose A case in which cefiderocol was used for the treatment of ventriculitis caused by difficult-to-treat resistance in Pseudomonas aeruginosa (DTR-PA) is reported. Summary A 56-year-old female with a relevant past medical history significant for type 2 diabetes mellitus was admitted to the intensive care unit for an acute large intraparenchymal hemorrhage. Despite numerous attempts at neurosurgical interventions and procedures (eg, hematoma evacuation, external ventricular drain placement, ventriculoperitoneal shunt placement), the patient developed worsening hydrocephalus. While dependent on mechanical ventilation, she developed multiple episodes of ventilator-associated pneumonia (VAP) secondary to pansusceptible Pseudomonas aeruginosa infection treated with courses of cefepime and meropenem. Eventually, the patient developed DTR-PA VAP and was treated with ceftolozane/tazobactam. On day 124, she was unresponsive and febrile, and cerebrospinal fluid (CSF) culture grew DTR-PA. Although susceptibility testing indicated that the cultured P. aeruginosa isolate was susceptible to ceftolozane/tazobactam at a minimum inhibitory concentration of 4 µg/mL, the clinical decision to utilize cefiderocol instead was made. Despite use of cefiderocol for a 3-week course, neurologic examination findings remained poor. After multiple repeat CSF cultures suggesting no growth, 3 weeks after completion of therapy CSF culture grew DTR-PA again, with a similar susceptibility pattern. Thus, the patient was restarted on an additional 9 weeks of cefiderocol. After completion of a total of 12 weeks of cefiderocol therapy, repeat CSF cultures demonstrated microbiological eradication and the patient remained clinically stable. Conclusion This patient case demonstrates cefiderocol's potential clinical utility for the treatment of DTR-PA ventriculitis, providing real-world context in an area with limited clinical data.