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Functional metagenomic approach to identify overlooked antibiotic resistance mutations in bacterial rRNA

Our knowledge as to how bacteria acquire antibiotic resistance is still fragmented, especially for the ribosome-targeting drugs. In this study, with the aim of finding novel mechanisms that render bacteria resistant to the ribosome-targeting antibiotics, we developed a general method to systematical...

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Detalles Bibliográficos
Autores principales: Miyazaki, Kentaro, Kitahara, Kei
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Nature Publishing Group UK 2018
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5882664/
https://www.ncbi.nlm.nih.gov/pubmed/29615654
http://dx.doi.org/10.1038/s41598-018-23474-4
Descripción
Sumario:Our knowledge as to how bacteria acquire antibiotic resistance is still fragmented, especially for the ribosome-targeting drugs. In this study, with the aim of finding novel mechanisms that render bacteria resistant to the ribosome-targeting antibiotics, we developed a general method to systematically screen for antibiotic resistant 16 S ribosomal RNAs (rRNAs), which are the major target for multiple antibiotics (e.g. spectinomycin, tetracycline, and aminoglycosides), and identify point mutations therein. We used Escherichia coli ∆7, a null mutant of the rrn (ribosomal RNA) operons, as a surrogate host organism to construct a metagenomic library of 16 S rRNA genes from the natural (non-clinical) environment. The library was screened for spectinomycin resistance to obtain four resistant 16 S rRNA genes from non-E. coli bacterial species. Bioinformatic analysis and site-directed mutagenesis identified three novel mutations - U1183C (the first mutation discovered in a region other than helix 34), and C1063U and U1189C in helix 34 - as well as three well-described mutations (C1066U, C1192G, and G1193A). These results strongly suggest that uncharacterized antibiotic resistance mutations still exist, even for traditional antibiotics.