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Characterization of SCCmec Instability in Methicillin-Resistant Staphylococcus aureus Affecting Adjacent Chromosomal Regions, Including the Gene for Staphylococcal Protein A (spa)
Staphylococcal cassette chromosome mec (SCCmec) represents a sequence of clear clinical and diagnostic importance in staphylococci. At a minimum the chromosomal cassette contains the mecA gene encoding PBP2a but frequently also includes additional antibiotic resistance genes (e.g., ermA and aadC; ma...
Autores principales: | , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
American Society for Microbiology
2022
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9017337/ https://www.ncbi.nlm.nih.gov/pubmed/35254090 http://dx.doi.org/10.1128/aac.02374-21 |
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author | Scharn, C. R. Tickler, I. A. Tenover, F. C. Goering, R. V. |
author_facet | Scharn, C. R. Tickler, I. A. Tenover, F. C. Goering, R. V. |
author_sort | Scharn, C. R. |
collection | PubMed |
description | Staphylococcal cassette chromosome mec (SCCmec) represents a sequence of clear clinical and diagnostic importance in staphylococci. At a minimum the chromosomal cassette contains the mecA gene encoding PBP2a but frequently also includes additional antibiotic resistance genes (e.g., ermA and aadC; macrolide and aminoglycoside resistance, respectively). Certain regions within SCCmec elements are hot spots for sequence instability due to cassette-specific recombinases and a variety of internal mobile elements. SCCmec changes may affect not only cassette stability but the integrity of adjacent chromosomal sequences (e.g., the staphylococcal protein A gene; spa). We investigated SCCmec stability in methicillin-resistant Staphylococcus aureus (MRSA) strains carrying one of four SCCmec types cultured in the absence of antimicrobial selection over a 3-month period. SCCmec rearrangements were first detected in cefoxitin-susceptible variants after 2 months of passage, and most commonly showed precise excision of the SCCmec element. Sequence analysis after 3 months revealed both precise SCCmec excision and a variety of SCCmec internal deletions, some including extensive adjacent chromosomal loss, including spa. No empty cassettes (i.e., loss of just mecA from SCCmec) were observed among the variants. SCCmec stability was influenced both by internal mobile elements (IS431) as well as the host cell environment. Genotypically similar clinical isolates with deletions in the spa gene were also included for purposes of comparison. The results indicate a role for host-cell influence and the IS431 element on SCCmec stability. |
format | Online Article Text |
id | pubmed-9017337 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2022 |
publisher | American Society for Microbiology |
record_format | MEDLINE/PubMed |
spelling | pubmed-90173372022-04-20 Characterization of SCCmec Instability in Methicillin-Resistant Staphylococcus aureus Affecting Adjacent Chromosomal Regions, Including the Gene for Staphylococcal Protein A (spa) Scharn, C. R. Tickler, I. A. Tenover, F. C. Goering, R. V. Antimicrob Agents Chemother Mechanisms of Resistance Staphylococcal cassette chromosome mec (SCCmec) represents a sequence of clear clinical and diagnostic importance in staphylococci. At a minimum the chromosomal cassette contains the mecA gene encoding PBP2a but frequently also includes additional antibiotic resistance genes (e.g., ermA and aadC; macrolide and aminoglycoside resistance, respectively). Certain regions within SCCmec elements are hot spots for sequence instability due to cassette-specific recombinases and a variety of internal mobile elements. SCCmec changes may affect not only cassette stability but the integrity of adjacent chromosomal sequences (e.g., the staphylococcal protein A gene; spa). We investigated SCCmec stability in methicillin-resistant Staphylococcus aureus (MRSA) strains carrying one of four SCCmec types cultured in the absence of antimicrobial selection over a 3-month period. SCCmec rearrangements were first detected in cefoxitin-susceptible variants after 2 months of passage, and most commonly showed precise excision of the SCCmec element. Sequence analysis after 3 months revealed both precise SCCmec excision and a variety of SCCmec internal deletions, some including extensive adjacent chromosomal loss, including spa. No empty cassettes (i.e., loss of just mecA from SCCmec) were observed among the variants. SCCmec stability was influenced both by internal mobile elements (IS431) as well as the host cell environment. Genotypically similar clinical isolates with deletions in the spa gene were also included for purposes of comparison. The results indicate a role for host-cell influence and the IS431 element on SCCmec stability. American Society for Microbiology 2022-03-07 /pmc/articles/PMC9017337/ /pubmed/35254090 http://dx.doi.org/10.1128/aac.02374-21 Text en Copyright © 2022 Scharn 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 Scharn, C. R. Tickler, I. A. Tenover, F. C. Goering, R. V. Characterization of SCCmec Instability in Methicillin-Resistant Staphylococcus aureus Affecting Adjacent Chromosomal Regions, Including the Gene for Staphylococcal Protein A (spa) |
title | Characterization of SCCmec Instability in Methicillin-Resistant Staphylococcus aureus Affecting Adjacent Chromosomal Regions, Including the Gene for Staphylococcal Protein A (spa) |
title_full | Characterization of SCCmec Instability in Methicillin-Resistant Staphylococcus aureus Affecting Adjacent Chromosomal Regions, Including the Gene for Staphylococcal Protein A (spa) |
title_fullStr | Characterization of SCCmec Instability in Methicillin-Resistant Staphylococcus aureus Affecting Adjacent Chromosomal Regions, Including the Gene for Staphylococcal Protein A (spa) |
title_full_unstemmed | Characterization of SCCmec Instability in Methicillin-Resistant Staphylococcus aureus Affecting Adjacent Chromosomal Regions, Including the Gene for Staphylococcal Protein A (spa) |
title_short | Characterization of SCCmec Instability in Methicillin-Resistant Staphylococcus aureus Affecting Adjacent Chromosomal Regions, Including the Gene for Staphylococcal Protein A (spa) |
title_sort | characterization of sccmec instability in methicillin-resistant staphylococcus aureus affecting adjacent chromosomal regions, including the gene for staphylococcal protein a (spa) |
topic | Mechanisms of Resistance |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9017337/ https://www.ncbi.nlm.nih.gov/pubmed/35254090 http://dx.doi.org/10.1128/aac.02374-21 |
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