Deletions in a ribosomal protein-coding gene are associated with tigecycline resistance in Enterococcus faecium
Autor: | Michael Hornsey, Willem van Schaik, Nicholas J. Loman, Marc Niebel, Damon Huber, Rachel Pike, David W. Wareham, Miruna D. David, Neil Woodford, Beryl Oppenheim, Robert Hill, Joshua Quick, Ana M. Guzman Prieto |
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Rok vydání: | 2015 |
Předmět: |
DNA
Bacterial Ribosomal Proteins Microbiology (medical) Enterococcus faecium Molecular Sequence Data Minocycline Microbial Sensitivity Tests Drug resistance Tigecycline Biology Microbiology Minimum inhibitory concentration Ribosomal protein Drug Resistance Bacterial medicine Pharmacology (medical) Gene Gram-Positive Bacterial Infections Sequence Deletion Genetics Antiinfective agent Sequence Analysis DNA General Medicine biology.organism_classification Anti-Bacterial Agents Infectious Diseases Amino Acid Substitution Enterococcus Genome Bacterial medicine.drug |
Zdroj: | International Journal of Antimicrobial Agents. 46:572-575 |
ISSN: | 0924-8579 |
DOI: | 10.1016/j.ijantimicag.2015.07.009 |
Popis: | Enterococcus faecium is an emerging nosocomial pathogen associated with antibiotic therapy in the hospital environment. Whole-genome sequences were determined for three pairs of related, consecutively collected E. faecium clinical isolates to determine putative mechanisms of resistance to tigecycline. The first isolates (1S, 2S and 3S) in each of the three pairs were sensitive to tigecycline [minimum inhibitory concentration (MIC) of 0.125 mg/L]. Following tigecycline therapy, the second isolate in each pair demonstrated increased resistance to tigecycline. Two isolates (1R and 2R) were resistant (MIC of 8 mg/L) and one isolate (3I) demonstrated reduced susceptibility (MIC of 0.5 mg/L). Mutations distinguishing each pair of sensitive and resistant isolates were determined through alignment to a reference genome and variant detection. In addition, a de novo assembly of each isolate genome was constructed to confirm mutations. A total of 16 mutations in eleven coding sequences were determined. Mutations in the rpsJ gene, which encodes a structural protein forming part of the 30S ribosomal subunit, were detected in each of the pairs. Mutations were in regions proximal to the predicted tigecycline-binding site. Predicted amino acid substitutions were detected in 1R and 3I. The resistant strains were additionally associated with deletions of 15 nucleotides (2R) and 3 nucleotides (1R). This study confirms that amino acid substitutions in rpsJ contribute towards reduced susceptibility to tigecycline and suggests that deletions may be required for tigecycline resistance in E. faecium. |
Databáze: | OpenAIRE |
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