Testing Rifaximin's Effectiveness Against Clostridium Difficile
Author Information
Author(s): S. Huhulescu, U. Sagel, A. Fiedler, V. Pecavar, M. Blaschitz, G. Wewalka, F. Allerberger, A. Indra
Primary Institution: Austrian Agency for Health and Food Safety (AGES)
Hypothesis
Can the disc diffusion method be used to test the in vitro susceptibility of Clostridium difficile to rifaximin?
Conclusion
The study found that rifaximin may be a suitable candidate for disc diffusion testing despite its water-insolubility.
Supporting Evidence
- 62 strains showed reduced susceptibility with an MIC of at least 32 µg ml−1.
- Rifaximin disc diffusion yielded results correlating with broth microdilution in 98.4% of tested strains.
- The prevalence of reduced susceptibility was 7.5% for all isolates tested.
- For PCR ribotype 027, the prevalence of reduced susceptibility was 26%.
- Rifaximin exhibited high activity against C. difficile in vitro.
Takeaway
Researchers wanted to see if a simple test could check if a medicine works against a germ that causes diarrhea. They found it does work well.
Methodology
The study tested 1082 Clostridium difficile isolates using disc diffusion and broth microdilution methods to determine susceptibility to rifaximin.
Limitations
The study did not establish official breakpoints for rifaximin susceptibility testing.
Participant Demographics
The study included 1082 Clostridium difficile isolates from various sources, including clinical isolates and reference strains.
Statistical Information
P-Value
p<0.001
Statistical Significance
p<0.05
Digital Object Identifier (DOI)
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