Streptococcus halichoeri: Comparative Genomics of an Emerging Pathogen

Streptococcus halichoeri is an emerging pathogen with a variety of host species and zoonotic potential. It has been isolated from grey seals and other marine mammals as well as from human infections. Beginning in 2010, two concurrent epidemics were identified in Finland, in fur animals and domestic...

Full description

Saved in:
Bibliographic Details
Main Authors: Kirsi Aaltonen, Ravi Kant, Marjut Eklund, Mirja Raunio-Saarnisto, Lars Paulin, Olli Vapalahti, Thomas Grönthal, Merja Rantala, Tarja Sironen
Format: Article
Language:English
Published: Wiley 2020-01-01
Series:International Journal of Genomics
Online Access:http://dx.doi.org/10.1155/2020/8708305
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1832560704699236352
author Kirsi Aaltonen
Ravi Kant
Marjut Eklund
Mirja Raunio-Saarnisto
Lars Paulin
Olli Vapalahti
Thomas Grönthal
Merja Rantala
Tarja Sironen
author_facet Kirsi Aaltonen
Ravi Kant
Marjut Eklund
Mirja Raunio-Saarnisto
Lars Paulin
Olli Vapalahti
Thomas Grönthal
Merja Rantala
Tarja Sironen
author_sort Kirsi Aaltonen
collection DOAJ
description Streptococcus halichoeri is an emerging pathogen with a variety of host species and zoonotic potential. It has been isolated from grey seals and other marine mammals as well as from human infections. Beginning in 2010, two concurrent epidemics were identified in Finland, in fur animals and domestic dogs, respectively. The fur animals suffered from a new disease fur animal epidemic necrotic pyoderma (FENP) and the dogs presented with ear infections with poor treatment response. S. halichoeri was isolated in both studies, albeit among other pathogens, indicating a possible role in the disease etiologies. The aim was to find a possible common origin of the fur animal and dog isolates and study the virulence factors to assess pathogenic potential. Isolates from seal, human, dogs, and fur animals were obtained for comparison. The whole genomes were sequenced from 20 different strains using the Illumina MiSeq platform and annotated using an automatic annotation pipeline RAST. The core and pangenomes were formed by comparing the genomes against each other in an all-against-all comparison. A phylogenetic tree was constructed using the genes of the core genome. Virulence factors were assessed using the Virulence Factor Database (VFDB) concentrating on the previously confirmed streptococcal factors. A core genome was formed which encompassed approximately half of the genes in Streptococcus halichoeri. The resulting core was nearly saturated and would not change significantly by adding more genomes. The remaining genes formed the pangenome which was highly variable and would still evolve after additional genomes. The results highlight the great adaptability of this bacterium possibly explaining the ease at which it switches hosts and environments. Virulence factors were also analyzed and were found primarily in the core genome. They represented many classes and functions, but the largest single category was adhesins which again supports the marine origin of this species.
format Article
id doaj-art-e71a03e6d4654c1b8bc1387970624a82
institution Kabale University
issn 2314-436X
2314-4378
language English
publishDate 2020-01-01
publisher Wiley
record_format Article
series International Journal of Genomics
spelling doaj-art-e71a03e6d4654c1b8bc1387970624a822025-02-03T01:26:58ZengWileyInternational Journal of Genomics2314-436X2314-43782020-01-01202010.1155/2020/87083058708305Streptococcus halichoeri: Comparative Genomics of an Emerging PathogenKirsi Aaltonen0Ravi Kant1Marjut Eklund2Mirja Raunio-Saarnisto3Lars Paulin4Olli Vapalahti5Thomas Grönthal6Merja Rantala7Tarja Sironen8Department of Veterinary Biosciences, Faculty of Veterinary Medicine, University of Helsinki, Helsinki, FinlandDepartment of Veterinary Biosciences, Faculty of Veterinary Medicine, University of Helsinki, Helsinki, FinlandDepartment of Equine and Small Animal Medicine, Faculty of Veterinary Medicine, University of Helsinki, Helsinki, FinlandFinnish Food Authority, Seinäjoki, FinlandInstitute of Biotechnology, University of Helsinki, Helsinki, FinlandDepartment of Veterinary Biosciences, Faculty of Veterinary Medicine, University of Helsinki, Helsinki, FinlandDepartment of Equine and Small Animal Medicine, Faculty of Veterinary Medicine, University of Helsinki, Helsinki, FinlandDepartment of Equine and Small Animal Medicine, Faculty of Veterinary Medicine, University of Helsinki, Helsinki, FinlandDepartment of Veterinary Biosciences, Faculty of Veterinary Medicine, University of Helsinki, Helsinki, FinlandStreptococcus halichoeri is an emerging pathogen with a variety of host species and zoonotic potential. It has been isolated from grey seals and other marine mammals as well as from human infections. Beginning in 2010, two concurrent epidemics were identified in Finland, in fur animals and domestic dogs, respectively. The fur animals suffered from a new disease fur animal epidemic necrotic pyoderma (FENP) and the dogs presented with ear infections with poor treatment response. S. halichoeri was isolated in both studies, albeit among other pathogens, indicating a possible role in the disease etiologies. The aim was to find a possible common origin of the fur animal and dog isolates and study the virulence factors to assess pathogenic potential. Isolates from seal, human, dogs, and fur animals were obtained for comparison. The whole genomes were sequenced from 20 different strains using the Illumina MiSeq platform and annotated using an automatic annotation pipeline RAST. The core and pangenomes were formed by comparing the genomes against each other in an all-against-all comparison. A phylogenetic tree was constructed using the genes of the core genome. Virulence factors were assessed using the Virulence Factor Database (VFDB) concentrating on the previously confirmed streptococcal factors. A core genome was formed which encompassed approximately half of the genes in Streptococcus halichoeri. The resulting core was nearly saturated and would not change significantly by adding more genomes. The remaining genes formed the pangenome which was highly variable and would still evolve after additional genomes. The results highlight the great adaptability of this bacterium possibly explaining the ease at which it switches hosts and environments. Virulence factors were also analyzed and were found primarily in the core genome. They represented many classes and functions, but the largest single category was adhesins which again supports the marine origin of this species.http://dx.doi.org/10.1155/2020/8708305
spellingShingle Kirsi Aaltonen
Ravi Kant
Marjut Eklund
Mirja Raunio-Saarnisto
Lars Paulin
Olli Vapalahti
Thomas Grönthal
Merja Rantala
Tarja Sironen
Streptococcus halichoeri: Comparative Genomics of an Emerging Pathogen
International Journal of Genomics
title Streptococcus halichoeri: Comparative Genomics of an Emerging Pathogen
title_full Streptococcus halichoeri: Comparative Genomics of an Emerging Pathogen
title_fullStr Streptococcus halichoeri: Comparative Genomics of an Emerging Pathogen
title_full_unstemmed Streptococcus halichoeri: Comparative Genomics of an Emerging Pathogen
title_short Streptococcus halichoeri: Comparative Genomics of an Emerging Pathogen
title_sort streptococcus halichoeri comparative genomics of an emerging pathogen
url http://dx.doi.org/10.1155/2020/8708305
work_keys_str_mv AT kirsiaaltonen streptococcushalichoericomparativegenomicsofanemergingpathogen
AT ravikant streptococcushalichoericomparativegenomicsofanemergingpathogen
AT marjuteklund streptococcushalichoericomparativegenomicsofanemergingpathogen
AT mirjarauniosaarnisto streptococcushalichoericomparativegenomicsofanemergingpathogen
AT larspaulin streptococcushalichoericomparativegenomicsofanemergingpathogen
AT ollivapalahti streptococcushalichoericomparativegenomicsofanemergingpathogen
AT thomasgronthal streptococcushalichoericomparativegenomicsofanemergingpathogen
AT merjarantala streptococcushalichoericomparativegenomicsofanemergingpathogen
AT tarjasironen streptococcushalichoericomparativegenomicsofanemergingpathogen