Unlocking Cefiderocol: Effective Treatment for Complicated Hospital-Acquired Infections

Introduction

Microorganisms are becoming increasingly resistant to antimicrobials, leading to a decline in the effectiveness of existing treatments, including colistin. This issue is particularly severe in Poland, where drug resistance levels among several bacteria are alarmingly high.

New formulations like cefiderocol, ceftazidime/avibactam, meropenem/vaborbactam, eravacycline, and plazomicin aim to combat multi-drug resistant Gram-negative pathogens, particularly carbapenem-resistant Enterobacterales.

Cefiderocol, introduced in the European Union in 2020, targets infections with few treatment options caused by susceptible Gram-negative bacteria. It is approved by the FDA for complicated urinary tract infections (cUTIs) and hospital-acquired pneumonia (HAP). Cefiderocol is stable against all classes of beta-lactamases, including metallo-beta-lactamases.

Meropenem/vaborbactam, approved in Europe in 2018, is indicated for cUTIs, complicated intra-abdominal infections (cIAIs), and HAP. It resists class A and C beta-lactamases but is not effective against metallo-beta-lactamases. Ceftazidime/avibactam, approved in 2016, shares similar uses and resistance profiles but is also not stable against metallo-beta-lactamases. The addition of aztreonam to these combinations has yielded mixed results.

Klebsiella pneumoniae, a significant Gram-negative pathogen, frequently causes community and hospital infections. Its multi-drug resistant strains pose a major threat in hospital settings, particularly those harboring New Delhi metallo-beta-lactamase (NDM) and OXA-48.

In this report, we present a case where cefiderocol was successfully utilized after the failure of other antibiotic combinations in a critical intra-abdominal infection caused by resistant Klebsiella pneumoniae strains.

Case Presentation

A 72-year-old woman with a complex medical history underwent a kidney transplant at Wroclaw University Hospital. Following surgery, she developed graft thrombosis, leading to renal vein thrombectomy. Four weeks later, her abdominal CT scans revealed multiple abscesses, and blood cultures identified Klebsiella pneumoniae NDM, OXA-48. Initially, she was treated with meropenem combined with colistin, but her condition required graft removal and admission to the ICU for intra-abdominal sepsis.

Her previous medical history included end-stage renal failure, nephritis, peritoneal dialysis, and various chronic conditions. Upon ICU admission, she was sedated, intubated, and mechanically ventilated, with norepinephrine for blood pressure support. Antibiotic therapy included meropenem, colistin, and vancomycin, while continuous veno-venous hemodiafiltration was initiated.

The patient’s condition worsened, with increased levels of infection biomarkers leading to septic shock. Antibiotic therapy was adjusted several times, including the use of meropenem/vaborbactam and linezolid. Imaging revealed fluid collections, prompting a change to fosfomycin and tigecycline. Despite treatment, her condition remained critical.

On ICU day 10, cultures revealed Klebsiella pneumoniae strains sensitive to cefiderocol and colistin. Due to escalating infection and resistance, cefiderocol was included in her therapy on ICU day 37. Over the next eight days, her condition improved significantly, with decreased inflammatory markers and better wound healing.

By ICU day 56, she no longer required continuous renal replacement therapy and was transferred for further care, showing a significant recovery.

Discussion

Intra-abdominal infections are a common complication of surgical procedures and require immediate and effective management. Surgical infections are leading causes of sepsis, with high mortality rates among affected patients. This case illustrates a severe intra-abdominal infection in a renal transplant patient, emphasizing the need for prompt diagnosis, appropriate antibiotic therapy, and surgical intervention.

The initial broad-spectrum antibiotics were in line with sepsis treatment guidelines, given the rising resistance in Gram-negative bacteria. The case highlights the challenge posed by multidrug-resistant Klebsiella pneumoniae strains, leading to adjustments in therapy until cefiderocol became available.

The use of cefiderocol proved effective against the resistant strains, facilitating recovery after a prolonged and challenging treatment course. Timely access to new antibiotics can enhance the management of such infections, minimizing the risk of severe outcomes.

Conclusion

This case demonstrates that effective surgical management, intensive care, and targeted antibiotic therapy can improve patient outcomes in severe sepsis situations. While initial treatments with meropenem/vaborbactam and ceftazidime/avibactam were essential, cefiderocol eventually provided a definitive resolution of the infection. Enhancements in antibiotic availability could significantly affect recovery rates in critical cases.