Antimicrobial resistance to human-derived Clostridioides (Clostridium) difficile found that resistance to metronidazole, vancomycin, fidaxomicin, meropenem, and piperacillin/tazobactam is rarely reported, while second-generation fluoroquinolones and clindamycin displayed high levels of resistance, according to data published in Antimicrobial Resistance and Infection Control.

Study authors searched MEDLINE (PubMed), Scopus, Embase, Cochrane Library, and Web of Science for studies focusing on antimicrobial susceptibility testing in C difficile published between 1992 and 2019.

Study authors performed a systemic review and meta-analysis of 111 studies and calculated a weighted pooled resistance (WPR) for each antimicrobial:

  • Amoxicillin/clauvlanate: 0% (95% CI, 0-0%); breakpoint: 16/8 mg/L or greater
  • Ceftriaxone: 47% (95% CI, 29-65%); breakpoint: 64 mg/L or greater
  • Ciprofloxacin: 95% (95% CI, 85-100%); breakpoint: 8 mg/L or greater
  • Clindamycin: 59% (95% CI, 53-65%); breakpoint: 8 mg/L or greater
  • Meropenem: 0% (95% CI, 0-1%); breakpoint: 16 mg/L or greater
  • Metronidazole: 1.0% (95% CI, 0-3%); breakpoint: greater than 2 mg/L
  • Metronidazole: 0% (95% CI, 0-0%); breakpoint: 32 mg/L or greater
  • Moxifloxacin: 49% (95% CI, 30-67%); breakpoint: 4 mg/L or greater
  • Moxifloxacin: 32% (95% CI, 25-40%); breakpoint: 8 mg/L or greater
  • Piperacillin/tazobactam: 0% (95% CI, 0-0%); breakpoint: greater than 128/4 mg/L
  • Rifampin: 37% (95% CI, 18-58%); breakpoint: 0.004 mg/L or greater
  • Tetracycline: 20% (95% CI, 14-27%); breakpoint: 16 mg/L or greater
  • Tigecycline: 1% (95% CI, 0-3%); breakpoint: 0.25 mg/L or greater
  • Vancomycin: 1% (95% CI, 0-2%); breakpoint: greater than 2 mg/L
  • Vancomycin: 0% (95% CI, 0-1%); breakpoint: 4 mg/L or greater
  • Vancomycin: 0% (95% CI, 0-0%); breakpoints: 16 mg/L or greater, 32 mg/L or greater

Resistance to fidaxomicin was reported in one isolate (0.08%) with a breakpoint of 8 mg/L or greater.


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Results from systemic review and meta-analysis found that resistance was rare for metronidazole, vancomycin, fidaxomicin, meropenem, and piperacillin-tazobactam. Regarding alternative C difficile infection treatment drugs, tigecycline had a lower resistance rate than rifampicin. High risk antimicrobials, such as second-generation fluoroquinolones and clindamycin, for C difficile infection development showed a high level of resistance. Amoxicillin/clavulanate showed almost no resistance, and tetracycline resistance was present in one fifth of human clinical isolates.

Reference

Sholeh M, Krutova M, Forouzesh, M, et al. Antimicrobial resistance in Clostridioides (Clostridium) difficile derived from humans: a systematic review and meta-analysis. Antimicrob Resist Infect Control. 2020; 9: 158