| Literature DB >> 18462927 |
Beatrice Vitali1, Silvia Turroni, Stefania Serina, Margherita Sosio, Lucia Vannini, Marco Candela, Maria Elisabetta Guerzoni, Patrizia Brigidi.
Abstract
Nucleotide mutations inside a core region of the rpoB gene, encoding the beta subunit of RNA polymerase, were found in rifaximin-resistant mutants of Bifidobacterium. Five different missense mutations of codons 513, 516, 522 and 529 were identified. Further aspects of rifaximin resistance were investigated, using Bifidobacterium infantis BI07 as a model strain. Partial resistance of RNA polymerase of a BI07 mutant at a rifaximin concentration >10 microg/mL was observed by cell-free transcription assay. Mass spectrometry detection of rifaximin in the cellular pellet of the BI07 resistant mutant, as well as changes in biosynthesis of saturated and cyclopropane fatty acids during growth, suggested a reduction in membrane permeability for the antibiotic moiety.Entities:
Mesh：
Substances：
Year: 2008 PMID： 18462927 DOI： 10.1016/j.ijantimicag.2008.02.002
Source DB: PubMed Journal: Int J Antimicrob Agents ISSN： 0924-8579 Impact factor: 5.283