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Re-emergence of methicillin susceptibility in a resistant lineage of Staphylococcus aureus

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Title: Re-emergence of methicillin susceptibility in a resistant lineage of Staphylococcus aureus
Authors: Ledda, A
Price, JR
Cole, K
Llewelyn, MJ
Kearns, AM
Crook, DW
Paul, J
Didelot, X
Item Type: Journal Article
Abstract: Objectives Methicil l in - resistant Staphylococcus aureus (MRSA) is a leading cause of hospital - associated infection. Acquired r esistance is encoded by the mecA gene or its homologue mecC but little is known about the evolutionary dynamics involved in gain and loss of resistance. The objective of this study was to obtain an expanded understanding of S. aureus methicilin resistance micro evolution in vivo , by focusing on a single lineage . Methods We compared the whole genome sequences of 231 isolates from a single epidemic lineage (clonal complex CC30 and spa - type t018) of S. aureus that caused an epidemic in the United Kingdom. Results We show that resistance to methicillin in this single lineage was gained on at least two separate occasions , one of which led to a clonal expansion around 1995 presumably caused by a selective advantage . Resistance was however subsequently lost in vivo by nine strains isolated between 2008 and 201 2 . We describe the genetic mechanisms involved in this loss of 40 resistance and the imperfect relationship between genotypic and phenotypic resistance . Conclusions The recent re - emergence of methicillin susceptibility in this epidemic lineage suggests a significant fitness cost of resistance and reduced selective advantage following the introduction in the mid 2000s of MRSA hospital control measures throughout the United Kingdom.
Issue Date: 20-Jan-2017
Date of Acceptance: 9-Dec-2016
URI: http://hdl.handle.net/10044/1/43739
DOI: https://dx.doi.org/10.1093/jac/dkw570
ISSN: 1460-2091
Publisher: Oxford University Press (OUP)
Start Page: 1285
End Page: 1288
Journal / Book Title: Journal of Antimicrobial Chemotherapy
Volume: 72
Issue: 5
Copyright Statement: VC The Author 2017. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please email: journals.permissions@oup.com.
Sponsor/Funder: Medical Research Council (MRC)
Funder's Grant Number: MR/K010174/1B
Keywords: Science & Technology
Life Sciences & Biomedicine
Infectious Diseases
Pharmacology & Pharmacy
1115 Pharmacology And Pharmaceutical Sciences
0605 Microbiology
1108 Medical Microbiology
Publication Status: Published
Appears in Collections:School of Public Health