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Research article - Peer-reviewed, 2021

Differences in the genome, methylome, and transcriptome do not differentiate isolates of Streptococcus equi subsp. equi from horses with acute clinical signs from isolates of inapparent carriers

Morris, Ellen Ruth A.; Boyle, Ashley G.; Riihimaeki, Miia; Aspan, Anna; Anis, Eman; Hillhouse, Andrew E.; Ivanov, Ivan; Bordin, Angela I.; Pringle, John; Cohen, Noah D.

Abstract

Streptococcus equi subsp. equi (SEE) is a host-restricted bacterium that causes the common infectious upper respiratory disease known as strangles in horses. Perpetuation of SEE infection appears attributable to inapparent carrier horses because it neither persists long-term in the environment nor infects other host mammals or vectors, and infection results in short-lived immunity. Whether pathogen factors enable SEE to remain in horses without causing clinical signs remains poorly understood. Thus, our objective was to use next-generation sequencing technologies to characterize the genome, methylome, and transcriptome of isolates of SEE from horses with acute clinical strangles and inapparent carrier horses-including isolates recovered from individual horses sampled repeatedly-to assess pathogen-associated changes that might reflect specific adaptions of SEE to the host that contribute to inapparent carriage. The accessory genome elements and methylome of SEE isolates from Sweden and Pennsylvania revealed no significant or consistent differences between acute clinical and inapparent carrier isolates of SEE. RNA sequencing of SEE isolates from Pennsylvania demonstrated no genes that were differentially expressed between acute clinical and inapparent carrier isolates of SEE. The absence of specific, consistent changes in the accessory genomes, methylomes, and transcriptomes of acute clinical and inapparent carrier isolates of SEE indicates that adaptations of SEE to the host are unlikely to explain the carrier state of SEE. Efforts to understand the carrier state of SEE should instead focus on host factors.

Published in

PLoS ONE
2021, volume: 16, number: 6, article number: e0252804
Publisher: PUBLIC LIBRARY SCIENCE

Authors' information

Morris, Ellen Ruth A.
Texas AandM University College Station
Boyle, Ashley G.
University of Pennsylvania
Swedish University of Agricultural Sciences, Department of Clinical Sciences
Swedish University of Agricultural Sciences, Department of Clinical Sciences
Anis, Eman
University of Pennsylvania
Hillhouse, Andrew E.
Texas AandM University College Station
Ivanov, Ivan
Texas AandM University College Station
Bordin, Angela I.
Texas AandM University College Station
Swedish University of Agricultural Sciences, Department of Clinical Sciences
Cohen, Noah D.
Texas AandM University College Station

UKÄ Subject classification

Clinical Science

Publication Identifiers

DOI: https://doi.org/10.1371/journal.pone.0252804

URI (permanent link to this page)

https://res.slu.se/id/publ/112761