Repository logo
 

Conservation of vaccine antigen sequences encoded by sequenced strains of Streptococcus equi subsp. equi.

Published version
Peer-reviewed

Change log

Authors

Morris, Ellen Ruth A  ORCID logo  https://orcid.org/0000-0002-7957-4642
Frykberg, Lars 
Jacobsson, Karin 

Abstract

BACKGROUND: Streptococcus equi subspecies equi (S equi) is the cause of Strangles, one of the most prevalent diseases of horses worldwide. Variation within the immunodominant SeM protein has been documented, but a new eight-component fusion protein vaccine, Strangvac, does not contain live S equi or SeM and conservation of the antigens it contains have not been reported. OBJECTIVE: To define the diversity of the eight Strangvac antigens across a diverse S equi population. STUDY DESIGN: Genomic description. METHODS: Antigen sequences from the genomes of 759 S equi isolates from 19 countries, recovered between 1955 and 2018, were analysed. Predicted amino acid sequences in the antigen fragments of SEQ0256(Eq5), SEQ0402(Eq8), SEQ0721(EAG), SEQ0855(SclF), SEQ0935(CNE), SEQ0999(IdeE), SEQ1817(SclI) and SEQ2101(SclC) in Strangvac and SeM were extracted from the 759 assembled genomes and compared. RESULTS: The predicted amino acid sequences of SclC, SclI and IdeE were identical across all 759 genomes. CNE was truncated in the genome of five (0.7%) isolates. SclF was absent from one genome and another encoded a single amino acid substitution. EAG was truncated in two genomes. Eq5 was truncated in four genomes and 123 genomes encoded a single amino acid substitution. Eq8 was truncated in three genomes, one genome encoded four amino acid substitutions and 398 genomes encoded a single amino acid substitution at the final amino acid of the Eq8 antigen fragment. Therefore, at least 1579 (99.9%) of 1580 amino acids in Strangvac were identical in 743 (97.9%) genomes, and all genomes encoded identical amino acid sequences for at least six of the eight Strangvac antigens. MAIN LIMITATIONS: Three hundred and seven (40.4%) isolates in this study were recovered from horses in the UK. CONCLUSIONS: The predicted amino acid sequences of antigens in Strangvac were highly conserved across this collection of S equi.

Description

Funder: Department of Large Animal Clinical Sciences


Funder: USDA‐NIFA AgriLife and the Link Equine Research Endowment


Funder: Texas A&M University; Id: http://dx.doi.org/10.13039/100007904


Funder: Formas


Funder: Intervacc AB


Funder: The Horse Trust


Funder: SEIB


Funder: Paul Mellon Foundation


Funder: Alice Noakes Memorial Charitable Trust


Funder: Ivo Trust


Funder: Tattersalls


Funder: The Elise Pilkington Charitable Trust


Funder: The European Breeders Fund


Funder: The Serth and Gates Charity


Funder: Margaret Giffen Charitable Trust


Funder: The Payne Gallwey Charitable Trust


Funder: The Stafford Trust


Funder: Marjorie Coote Animal Charity Trust


Funder: Beryl Evetts and Robert Luff Animal Welfare Trust


Funder: The Anne Duchess of Westminster’s Charitable Trust

Keywords

S equi, genetic conservation, horse, strangles, vaccine antigens, Horses, Animals, Streptococcus equi, Horse Diseases, Streptococcus, Streptococcal Infections

Journal Title

Equine Vet J

Conference Name

Journal ISSN

0425-1644
2042-3306

Volume Title

Publisher

Wiley
Sponsorship
Petplan Charitable Trust (S19‐741‐780)