Related Experiment Video

Updated: Aug 5, 2026

A Protocol to Characterize the Morphological Changes of Clostridium difficile in Response to Antibiotic Treatment
12:58

A Protocol to Characterize the Morphological Changes of Clostridium difficile in Response to Antibiotic Treatment

Published on: May 25, 2017

Case Commentary: Emergence of clinically relevant fidaxomicin-resistant Clostridioides difficile strains

Kevin W Garey1, Julian G Hurdle2,3

  • 1Department of Pharmacy Practice and Translational Research, University of Houston College of Pharmacy, Houston, Texas, USA.

Antimicrobial Agents and Chemotherapy
|August 3, 2026
PubMed

Insights

Fidaxomicin treatment for Clostridioides difficile infection (CDI) may lead to treatment failure due to emerging resistance. This case highlights the need for monitoring fidaxomicin resistance in CDI patients.

Area of Science:

  • Infectious Diseases
  • Microbiology
  • Pharmacology

Background:

  • Clostridioides difficile infection (CDI) presents limited therapeutic options.
  • Fidaxomicin is a preferred antibiotic for CDI, but resistance can emerge.
  • Clinical reports suggest potential for treatment failure due to fidaxomicin resistance.

Purpose of the Study:

  • To report a case of clinical failure in an elderly patient with CDI treated with fidaxomicin.
  • To investigate the emergence of fidaxomicin resistance during treatment.
  • To discuss the implications for CDI management and diagnostics.

Main Methods:

  • Case report of an elderly CDI patient treated with a pulsed-taper fidaxomicin regimen.
  • Determination of minimum inhibitory concentration (MIC) of fidaxomicin in baseline and relapse isolates.
  • Clinical observation of treatment response to fidaxomicin and subsequent vancomycin therapy.

Main Results:

  • The patient experienced clinical failure despite fidaxomicin treatment.
  • Fidaxomicin MIC increased significantly from baseline (0.05 μg/mL) to relapse isolates (32 μg/mL).
  • Symptoms resolved after switching to oral vancomycin, suggesting fidaxomicin resistance.

Conclusions:

  • Emergence of fidaxomicin resistance during CDI treatment can lead to clinical failure.
  • This challenges assumptions about high drug concentrations preventing resistance.
  • There is a critical need for improved surveillance and molecular diagnostics for fidaxomicin resistance in CDI.
Keywords:
Clostridioides difficile infectionRNA polymeraseantibioticsantimicrobial resistancemicrobiome

More Related Videos

Cefoperazone-treated Mouse Model of Clinically-relevant Clostridium difficile Strain R2029106:51

Cefoperazone-treated Mouse Model of Clinically-relevant Clostridium difficile Strain R20291

Published on: December 10, 2016

Related Concept Videos

Clinical Significance of Antibiotic Resistance01:25

Clinical Significance of Antibiotic Resistance

Methicillin-resistant Staphylococcus aureus (MRSA) presents a critical public health threat, arising from its capacity to resist β-lactam antibiotics due to acquisition of the mecA gene within the staphylococcal cassette chromosome mec (SCCmec). This gene encodes penicillin-binding protein 2a (PBP2a), which impairs binding efficacy of methicillin and other β-lactams. MRSA has evolved into distinct clonal lineages impacting humans and animals alike, reinforcing its significance within the One...
Inhibitors of Bacterial DNA Synthesis01:28

Inhibitors of Bacterial DNA Synthesis

Bacterial pathogens depend on precise and efficient DNA replication to sustain infection. Two type II topoisomerases—DNA gyrase and topoisomerase IV—are critical to this process, as they resolve DNA supercoiling and unlink chromosomes during replication. Fluoroquinolones, synthetic derivatives of quinolones, exploit this mechanism by stabilizing the transient DNA–enzyme cleavage complex, preventing strand religation, and causing lethal double-strand breaks. These antibiotics are selectively...
Drugs for Treatment of Diarrhea-Predominant IBS01:17

Drugs for Treatment of Diarrhea-Predominant IBS

Diarrhea-predominant irritable bowel syndrome (IBS-D) is a subtype of IBS characterized primarily by frequent, loose, or watery stools, abdominal pain, and abdominal discomfort. Therapeutic approaches to managing IBS-D include dietary changes, stress management techniques, and pharmaceutical interventions.
Two specific drugs used in the treatment are alosetron (Lotronex) and eluxadoline (Viberzi). Alosetron, a 5-HT3 antagonist, works by slowing the movement of stools in the gut, reducing bowel...
Antibiotic Selection00:57

Antibiotic Selection

Overview
Antimicrobial Effectiveness01:28

Antimicrobial Effectiveness

The effectiveness of antimicrobial agents depends on various factors influencing their ability to eliminate microbial populations. Larger microbial populations require more time for complete eradication, emphasizing the importance of population size analysis when evaluating antimicrobial efficacy.Microbial resistance to antimicrobial agents varies significantly. Highly resilient microorganisms include endospores, gram-negative bacteria, and non-enveloped viruses, while prions are exceptionally...
Drugs Affecting GI Tract Motility: Antimicrobials as Antidiarrheal Agents01:18

Drugs Affecting GI Tract Motility: Antimicrobials as Antidiarrheal Agents

Acute diarrhea, a common gastrointestinal disturbance, is characterized by the rapid evacuation of fluid stools, leading to an excessive weight in fluid. This condition typically arises from disorders affecting intestinal water and electrolyte transport. It can be triggered by an increased osmotic load within the intestine, excessive secretion of electrolytes and water, mucosal exudation of protein and fluid, or altered intestinal motility. The primary risks of acute diarrhea are dehydration...