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Emergence of Oxacillin Resistance in Stealth Methicillin-Resistant Staphylococcus aureus Due to mecA Sequence Instability
Staphylococcus aureus strains that possess a mecA gene but are phenotypically susceptible to oxacillin and cefoxitin (OS-MRSA) have been recognized for over a decade and are a challenge for diagnostic laboratories. The mechanisms underlying the discrepancy vary from isolate to isolate. We characteri...
Autores principales: | , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
American Society for Microbiology
2019
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6658785/ https://www.ncbi.nlm.nih.gov/pubmed/31109981 http://dx.doi.org/10.1128/AAC.00558-19 |
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author | Goering, Richard V. Swartzendruber, Erin A. Obradovich, Anne E. Tickler, Isabella A. Tenover, Fred C. |
author_facet | Goering, Richard V. Swartzendruber, Erin A. Obradovich, Anne E. Tickler, Isabella A. Tenover, Fred C. |
author_sort | Goering, Richard V. |
collection | PubMed |
description | Staphylococcus aureus strains that possess a mecA gene but are phenotypically susceptible to oxacillin and cefoxitin (OS-MRSA) have been recognized for over a decade and are a challenge for diagnostic laboratories. The mechanisms underlying the discrepancy vary from isolate to isolate. We characterized seven OS-MRSA clinical isolates of six different spa types from six different states by whole-genome sequencing to identify the nucleotide sequence changes leading to the OS-MRSA phenotype. The results demonstrated that oxacillin susceptibility was associated with mutations in regions of nucleotide repeats within mecA. Subinhibitory antibiotic exposure selected for secondary mecA mutations that restored oxacillin resistance. Thus, strains of S. aureus that contain mecA but are phenotypically susceptible can become resistant after antibiotic exposure, which may result in treatment failure. OS-MRSA warrant follow-up susceptibility testing to ensure detection of resistant revertants. |
format | Online Article Text |
id | pubmed-6658785 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2019 |
publisher | American Society for Microbiology |
record_format | MEDLINE/PubMed |
spelling | pubmed-66587852019-08-07 Emergence of Oxacillin Resistance in Stealth Methicillin-Resistant Staphylococcus aureus Due to mecA Sequence Instability Goering, Richard V. Swartzendruber, Erin A. Obradovich, Anne E. Tickler, Isabella A. Tenover, Fred C. Antimicrob Agents Chemother Mechanisms of Resistance Staphylococcus aureus strains that possess a mecA gene but are phenotypically susceptible to oxacillin and cefoxitin (OS-MRSA) have been recognized for over a decade and are a challenge for diagnostic laboratories. The mechanisms underlying the discrepancy vary from isolate to isolate. We characterized seven OS-MRSA clinical isolates of six different spa types from six different states by whole-genome sequencing to identify the nucleotide sequence changes leading to the OS-MRSA phenotype. The results demonstrated that oxacillin susceptibility was associated with mutations in regions of nucleotide repeats within mecA. Subinhibitory antibiotic exposure selected for secondary mecA mutations that restored oxacillin resistance. Thus, strains of S. aureus that contain mecA but are phenotypically susceptible can become resistant after antibiotic exposure, which may result in treatment failure. OS-MRSA warrant follow-up susceptibility testing to ensure detection of resistant revertants. American Society for Microbiology 2019-07-25 /pmc/articles/PMC6658785/ /pubmed/31109981 http://dx.doi.org/10.1128/AAC.00558-19 Text en Copyright © 2019 Goering et al. https://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution 4.0 International license (https://creativecommons.org/licenses/by/4.0/) . |
spellingShingle | Mechanisms of Resistance Goering, Richard V. Swartzendruber, Erin A. Obradovich, Anne E. Tickler, Isabella A. Tenover, Fred C. Emergence of Oxacillin Resistance in Stealth Methicillin-Resistant Staphylococcus aureus Due to mecA Sequence Instability |
title | Emergence of Oxacillin Resistance in Stealth Methicillin-Resistant Staphylococcus aureus Due to mecA Sequence Instability |
title_full | Emergence of Oxacillin Resistance in Stealth Methicillin-Resistant Staphylococcus aureus Due to mecA Sequence Instability |
title_fullStr | Emergence of Oxacillin Resistance in Stealth Methicillin-Resistant Staphylococcus aureus Due to mecA Sequence Instability |
title_full_unstemmed | Emergence of Oxacillin Resistance in Stealth Methicillin-Resistant Staphylococcus aureus Due to mecA Sequence Instability |
title_short | Emergence of Oxacillin Resistance in Stealth Methicillin-Resistant Staphylococcus aureus Due to mecA Sequence Instability |
title_sort | emergence of oxacillin resistance in stealth methicillin-resistant staphylococcus aureus due to meca sequence instability |
topic | Mechanisms of Resistance |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6658785/ https://www.ncbi.nlm.nih.gov/pubmed/31109981 http://dx.doi.org/10.1128/AAC.00558-19 |
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