In silico assigned resistance genes confer Bifidobacterium with partial resistance to aminoglycosides but not to β-lactams
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Additional File 1: Table S1.
Date
2013
Authors
Fouhy, Fiona
O'Connell Motherway, Mary
Fitzgerald, Gerald F.
Ross, R. Paul
Stanton, Catherine
van Sinderen, Douwe
Cotter, Paul D.
Journal Title
Journal ISSN
Volume Title
Publisher
Public Library of Science
Published Version
Abstract
Bifidobacteria have received significant attention due to their contribution to human gut health and the use of specific strains as probiotics. It is thus not surprising that there has also been significant interest with respect to their antibiotic resistance profile. Numerous culture-based studies have demonstrated that bifidobacteria are resistant to the majority of aminoglycosides, but are sensitive to β-lactams. However, limited research exists with respect to the genetic basis for the resistance of bifidobacteria to aminoglycosides. Here we performed an in-depth in silico analysis of putative Bifidobacterium-encoded aminoglycoside resistance proteins and β-lactamases and assess the contribution of these proteins to antibiotic resistance. The in silico-based screen detected putative aminoglycoside and β-lactam resistance proteins across the Bifidobacterium genus. Laboratory-based investigations of a number of representative bifidobacteria strains confirmed that despite containing putative β-lactamases, these strains were sensitive to β-lactams. In contrast, all strains were resistant to the aminoglycosides tested. To assess the contribution of genes encoding putative aminoglycoside resistance proteins in Bifidobacterium sp. two genes, namely Bbr_0651 and Bbr_1586, were targeted for insertional inactivation in B. breve UCC2003. As compared to the wild-type, the UCC2003 insertion mutant strains exhibited decreased resistance to gentamycin, kanamycin and streptomycin. This study highlights the associated risks of relying on the in silico assignment of gene function. Although several putative β-lactam resistance proteins are located in bifidobacteria, their presence does not coincide with resistance to these antibiotics. In contrast however, this approach has resulted in the identification of two loci that contribute to the aminoglycoside resistance of B. breve UCC2003 and, potentially, many other bifidobacteria.
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Keywords
Susceptibility testing method , Bile salt hydrolase , Antimicrobial susceptibility , Antibiotic resistance , Beta-lactamases , Breve UCC2003 , Bacterial resistance , Functional characterization , Genome annotation , Strain Yakult
Citation
Fouhy F, O’Connell Motherway M, Fitzgerald GF, Ross RP, Stanton C, van Sinderen D, et al. (2013) In Silico Assigned Resistance Genes Confer Bifidobacterium with Partial Resistance to Aminoglycosides but Not to Β-Lactams. PLoS ONE 8(12): e82653. doi:10.1371/journal.pone.0082653