Enhanced nasopharyngeal infection and shedding associated with an epidemic lineage of emm3 group A Streptococcus

Title: Enhanced nasopharyngeal infection and shedding associated with an epidemic lineage of emm3 group A Streptococcus
Authors: Afshar, B
Turner, CE
Lamagni, TL
Smith, K
Al-Shahib, A
Underwood, A
Holden, MTG
Efstratiou, A
Sriskandan, S
Item Type: Journal Article
Abstract: Background: A group A Streptococcus (GAS) lineage of genotype emm3, sequence type 15 (ST15) was associated with a 6 month upsurge in invasive GAS disease in the UK. The epidemic lineage (Lineage C) had lost 2 typical emm3 prophages, Φ315.1 and Φ315.2 associated with the superantigen ssa, but gained a different prophage (ΦUK-M3.1) associated with a different superantigen, speC and a DNAse spd1. Methods and Results: The presence of speC and spd1 in Lineage C ST15 strains enhanced both in vitro mitogenic and DNase activities over non-Lineage C ST15 strains. Invasive disease models in Galleria mellonella and SPEC-sensitive transgenic mice, revealed no difference in overall invasiveness of Lineage C ST15 strains compared with non-Lineage C ST15 strains, consistent with clinical and epidemiological analysis. Lineage C strains did however markedly prolong murine nasal infection with enhanced nasal and airborne shedding compared with non-Lineage C strains. Deletion of speC or spd1 in 2 Lineage C strains identified a possible role for spd1 in airborne shedding from the murine nasopharynx. Conclusions: Nasopharyngeal infection and shedding of Lineage C strains was enhanced compared with non-Lineage C strains and this was, in part, mediated by the gain of the DNase spd1 through prophage acquisition.
Issue Date: 1-May-2017
Date of Acceptance: 26-Apr-2017
ISSN: 2150-5608
Publisher: Taylor & Francis
Start Page: 1390
End Page: 1400
Journal / Book Title: Virulence
Volume: 8
Issue: 7
Copyright Statement: © 2017 Baharak Afshar, Claire E. Turner, Theresa L. Lamgni, Ken C. Smith, Ali Al-Shahib, Anthony Underwood, Matthew T. G. Holden, Androulla Efstratio u, and Shiranee Sriskandan. Published with license by Taylor & Francis. This is an Open Access article distributed under the terms of the Creative Commons Attribution License ( ), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The moral rights of the named author(s) have been asserted.
Sponsor/Funder: Wellcome Trust
Medical Research Council (MRC)
Medical Research Council (MRC)
Public Health England
National Institute for Health Research
National Institute for Health Research
Funder's Grant Number: 087732/Z/08/Z
Keywords: DNases
Streptococcus pyogenes
epidemic upsurge
genotype emm3
group A Streptococcus
invasive group A streptococcal disease
nasopharyngeal infection
serotype M3
Publication Status: Published
Appears in Collections:Department of Medicine
Faculty of Medicine

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