Case Commentary: Emergence of clinically relevant fidaxomicin-resistant Clostridioides difficile strains.
Kevin W Garey, Julian G Hurdle
✦ AI-curated · Sources linked
Case in brief
An elderly patient with Clostridioides difficile infection (CDI) experienced treatment failure while on a pulsed-taper fidaxomicin regimen. During relapse, the minimum inhibitory concentration (MIC) of the pathogen increased significantly from 0.05 µg/mL to 32 µg/mL. The patient's symptoms resolved only after switching to oral vancomycin, highlighting a potential emergence of fidaxomicin-resistant strains.
What made this case unusual
The significant increase in fidaxomicin MIC during treatment suggests the emergence of clinically relevant resistance, which is not commonly reported.
Diagnostic / clinical pearl
Clinicians should be aware that fidaxomicin resistance in C. difficile can develop during treatment, potentially leading to clinical failure.
Why it matters
This case emphasizes the need for enhanced surveillance and molecular diagnostics to identify fidaxomicin resistance in CDI, as it may become increasingly relevant in clinical practice.