Cargando…

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...

Descripción completa

Detalles Bibliográficos
Autores principales: Goering, Richard V., Swartzendruber, Erin A., Obradovich, Anne E., Tickler, Isabella A., Tenover, Fred C.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: American Society for Microbiology 2019
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
_version_ 1783439017587507200
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
work_keys_str_mv AT goeringrichardv emergenceofoxacillinresistanceinstealthmethicillinresistantstaphylococcusaureusduetomecasequenceinstability
AT swartzendrubererina emergenceofoxacillinresistanceinstealthmethicillinresistantstaphylococcusaureusduetomecasequenceinstability
AT obradovichannee emergenceofoxacillinresistanceinstealthmethicillinresistantstaphylococcusaureusduetomecasequenceinstability
AT ticklerisabellaa emergenceofoxacillinresistanceinstealthmethicillinresistantstaphylococcusaureusduetomecasequenceinstability
AT tenoverfredc emergenceofoxacillinresistanceinstealthmethicillinresistantstaphylococcusaureusduetomecasequenceinstability