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Published on: March 3, 2023

Genetic and proteomic characterization of rifaximin resistance in Bifidobacterium infantis BI07

Beatrice Vitali1, Silvia Turroni, Fabrizio Dal Piaz

  • 1Department of Pharmaceutical Sciences, CIRB-center for Biotechnology, University of Bologna, Via Belmeloro 6, 40126 Bologna, Italy.

Research in Microbiology
|April 6, 2007
PubMed

Insights

Investigating rifaximin resistance in Bifidobacterium infantis BI07 revealed a specific gene mutation. This finding impacts the use of antibiotic-probiotic combinations for intestinal disorders.

Area of Science:

  • Microbiology
  • Genetics
  • Pharmacology

Background:

  • Antibiotic-probiotic combinations are explored for managing intestinal disorders.
  • Understanding antibiotic resistance in probiotics like Bifidobacterium infantis is crucial.

Purpose of the Study:

  • To investigate rifaximin resistance in Bifidobacterium infantis BI07.
  • To assess the implications of this resistance for antibiotic-probiotic therapy.

Main Methods:

  • Selection of a rifaximin-resistant mutant of Bifidobacterium infantis BI07.
  • Sequencing of the rpoB gene's core region to identify mutations.
  • Proteomic analysis using two-dimensional electrophoresis and mass spectrometry to study metabolic changes.
  • Liquid chromatography coupled with tandem mass spectrometry to assess drug inactivation.

Main Results:

  • A miss-sense mutation in codon 513 of the rpoB gene was identified, substituting Gln with Arg.
  • Proteomic analysis indicated altered expression of chaperonins, regulatory factors, and metabolic enzymes in resistant strains.
  • No evidence of rifaximin inactivation by bacterial enzymatic activities was found.

Conclusions:

  • A specific mutation in the rpoB gene confers rifaximin resistance in Bifidobacterium infantis BI07.
  • Metabolic changes accompany rifaximin resistance, affecting protein expression.
  • Rifaximin resistance in this probiotic is not due to drug inactivation by bacterial enzymes.

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