Identification of Chryseobacterium spp. isolated from clinically affected fish in California, USA

Fernanda de Sebastião, Thomas P. Loch, David P. Marancik, Matt J. Griffin, Joe Maret, Christine Richey, Esteban Soto

Research output: Contribution to journalArticle

Abstract

Chryseobacterium spp. (Family Flavobacteriaceae) are emergent fish pathogens in Europe, Asia and North America. In 2016-2017, 7 bacterial isolates were recovered from posterior kidney or spleen of cultured diseased rainbow trout Oncorhynchus mykiss (n = 1), green sturgeon Acipenser medirostris (n = 1), white sturgeon A. transmontanus (n = 2), blue ram cichlid Mikrogeophagus ramirezi (n = 1), and returning fall Chinook salmon O. tshawytscha (n = 2) from different freshwater systems. Bacterial colonies were visible after 24-48 h incubation at 20°C on agar media. Isolates were Gram-negative, rod-shaped, catalase and oxidase positive. Amplification and partial sequence analysis of the 16S rRNA and gyrB genes allocated the microorganisms to the genus Chryseobacterium sharing 97.2-99.6% similarity to 6 described Chryseobacterium spp. at the 16S rRNA locus, and 87.8-99.1% similarity at gyrB. Phylogenetic analyses in conjunction with percent sequence identity suggest some of the recovered isolates may represent novel Chryseobacterium subspecies or species. The pathogenicity of 5 isolates was evaluated experimentally in rainbow trout (n = 60), brown trout Salmo trutta (n = 60) and white sturgeon (n = 36) in flow-through freshwater at 18°C. Approximately 107 CFU fish-1 was injected in the epaxial musculature of anesthetized animals. Limited mortality was observed and no bacteria were recovered from dead or moribund fish post-challenge. Thirty days post-challenge, survivors were euthanized and multiple tissues were collected and fixed for histological analysis. No consistent histopathological changes were observed in challenged or control fish. While results suggest the recovered Chryseobacterium spp. may be opportunistic pathogens, further research is warranted to better understand the role of these bacteria in fish disease.

Original languageEnglish (US)
Pages (from-to)227-234
Number of pages8
JournalDiseases of aquatic organisms
Volume136
Issue number3
DOIs
StatePublished - Nov 14 2019

Fingerprint

Chryseobacterium
Acipenser transmontanus
Acipenser medirostris
fish
Oncorhynchus mykiss
rainbow
Salmo trutta
pathogen
bacterium
ribosomal RNA
cichlid
Flavobacteriaceae
pathogenicity
fish diseases
agar
pathogens
subspecies
bacteria
Oncorhynchus tshawytscha
amplification

Keywords

  • 16S rRNA
  • Chryseobacterium
  • Flavobacterium
  • gyrB
  • North America

ASJC Scopus subject areas

  • Ecology, Evolution, Behavior and Systematics
  • Aquatic Science

Cite this

Sebastião, F. D., Loch, T. P., Marancik, D. P., Griffin, M. J., Maret, J., Richey, C., & Soto, E. (2019). Identification of Chryseobacterium spp. isolated from clinically affected fish in California, USA. Diseases of aquatic organisms, 136(3), 227-234. https://doi.org/10.3354/dao03409

Identification of Chryseobacterium spp. isolated from clinically affected fish in California, USA. / Sebastião, Fernanda de; Loch, Thomas P.; Marancik, David P.; Griffin, Matt J.; Maret, Joe; Richey, Christine; Soto, Esteban.

In: Diseases of aquatic organisms, Vol. 136, No. 3, 14.11.2019, p. 227-234.

Research output: Contribution to journalArticle

Sebastião, FD, Loch, TP, Marancik, DP, Griffin, MJ, Maret, J, Richey, C & Soto, E 2019, 'Identification of Chryseobacterium spp. isolated from clinically affected fish in California, USA', Diseases of aquatic organisms, vol. 136, no. 3, pp. 227-234. https://doi.org/10.3354/dao03409
Sebastião FD, Loch TP, Marancik DP, Griffin MJ, Maret J, Richey C et al. Identification of Chryseobacterium spp. isolated from clinically affected fish in California, USA. Diseases of aquatic organisms. 2019 Nov 14;136(3):227-234. https://doi.org/10.3354/dao03409
Sebastião, Fernanda de ; Loch, Thomas P. ; Marancik, David P. ; Griffin, Matt J. ; Maret, Joe ; Richey, Christine ; Soto, Esteban. / Identification of Chryseobacterium spp. isolated from clinically affected fish in California, USA. In: Diseases of aquatic organisms. 2019 ; Vol. 136, No. 3. pp. 227-234.
@article{edd54449c25c424084c4909a482c2a94,
title = "Identification of Chryseobacterium spp. isolated from clinically affected fish in California, USA",
abstract = "Chryseobacterium spp. (Family Flavobacteriaceae) are emergent fish pathogens in Europe, Asia and North America. In 2016-2017, 7 bacterial isolates were recovered from posterior kidney or spleen of cultured diseased rainbow trout Oncorhynchus mykiss (n = 1), green sturgeon Acipenser medirostris (n = 1), white sturgeon A. transmontanus (n = 2), blue ram cichlid Mikrogeophagus ramirezi (n = 1), and returning fall Chinook salmon O. tshawytscha (n = 2) from different freshwater systems. Bacterial colonies were visible after 24-48 h incubation at 20°C on agar media. Isolates were Gram-negative, rod-shaped, catalase and oxidase positive. Amplification and partial sequence analysis of the 16S rRNA and gyrB genes allocated the microorganisms to the genus Chryseobacterium sharing 97.2-99.6{\%} similarity to 6 described Chryseobacterium spp. at the 16S rRNA locus, and 87.8-99.1{\%} similarity at gyrB. Phylogenetic analyses in conjunction with percent sequence identity suggest some of the recovered isolates may represent novel Chryseobacterium subspecies or species. The pathogenicity of 5 isolates was evaluated experimentally in rainbow trout (n = 60), brown trout Salmo trutta (n = 60) and white sturgeon (n = 36) in flow-through freshwater at 18°C. Approximately 107 CFU fish-1 was injected in the epaxial musculature of anesthetized animals. Limited mortality was observed and no bacteria were recovered from dead or moribund fish post-challenge. Thirty days post-challenge, survivors were euthanized and multiple tissues were collected and fixed for histological analysis. No consistent histopathological changes were observed in challenged or control fish. While results suggest the recovered Chryseobacterium spp. may be opportunistic pathogens, further research is warranted to better understand the role of these bacteria in fish disease.",
keywords = "16S rRNA, Chryseobacterium, Flavobacterium, gyrB, North America",
author = "Sebasti{\~a}o, {Fernanda de} and Loch, {Thomas P.} and Marancik, {David P.} and Griffin, {Matt J.} and Joe Maret and Christine Richey and Esteban Soto",
year = "2019",
month = "11",
day = "14",
doi = "10.3354/dao03409",
language = "English (US)",
volume = "136",
pages = "227--234",
journal = "Diseases of Aquatic Organisms",
issn = "0177-5103",
publisher = "Inter-Research",
number = "3",

}

TY - JOUR

T1 - Identification of Chryseobacterium spp. isolated from clinically affected fish in California, USA

AU - Sebastião, Fernanda de

AU - Loch, Thomas P.

AU - Marancik, David P.

AU - Griffin, Matt J.

AU - Maret, Joe

AU - Richey, Christine

AU - Soto, Esteban

PY - 2019/11/14

Y1 - 2019/11/14

N2 - Chryseobacterium spp. (Family Flavobacteriaceae) are emergent fish pathogens in Europe, Asia and North America. In 2016-2017, 7 bacterial isolates were recovered from posterior kidney or spleen of cultured diseased rainbow trout Oncorhynchus mykiss (n = 1), green sturgeon Acipenser medirostris (n = 1), white sturgeon A. transmontanus (n = 2), blue ram cichlid Mikrogeophagus ramirezi (n = 1), and returning fall Chinook salmon O. tshawytscha (n = 2) from different freshwater systems. Bacterial colonies were visible after 24-48 h incubation at 20°C on agar media. Isolates were Gram-negative, rod-shaped, catalase and oxidase positive. Amplification and partial sequence analysis of the 16S rRNA and gyrB genes allocated the microorganisms to the genus Chryseobacterium sharing 97.2-99.6% similarity to 6 described Chryseobacterium spp. at the 16S rRNA locus, and 87.8-99.1% similarity at gyrB. Phylogenetic analyses in conjunction with percent sequence identity suggest some of the recovered isolates may represent novel Chryseobacterium subspecies or species. The pathogenicity of 5 isolates was evaluated experimentally in rainbow trout (n = 60), brown trout Salmo trutta (n = 60) and white sturgeon (n = 36) in flow-through freshwater at 18°C. Approximately 107 CFU fish-1 was injected in the epaxial musculature of anesthetized animals. Limited mortality was observed and no bacteria were recovered from dead or moribund fish post-challenge. Thirty days post-challenge, survivors were euthanized and multiple tissues were collected and fixed for histological analysis. No consistent histopathological changes were observed in challenged or control fish. While results suggest the recovered Chryseobacterium spp. may be opportunistic pathogens, further research is warranted to better understand the role of these bacteria in fish disease.

AB - Chryseobacterium spp. (Family Flavobacteriaceae) are emergent fish pathogens in Europe, Asia and North America. In 2016-2017, 7 bacterial isolates were recovered from posterior kidney or spleen of cultured diseased rainbow trout Oncorhynchus mykiss (n = 1), green sturgeon Acipenser medirostris (n = 1), white sturgeon A. transmontanus (n = 2), blue ram cichlid Mikrogeophagus ramirezi (n = 1), and returning fall Chinook salmon O. tshawytscha (n = 2) from different freshwater systems. Bacterial colonies were visible after 24-48 h incubation at 20°C on agar media. Isolates were Gram-negative, rod-shaped, catalase and oxidase positive. Amplification and partial sequence analysis of the 16S rRNA and gyrB genes allocated the microorganisms to the genus Chryseobacterium sharing 97.2-99.6% similarity to 6 described Chryseobacterium spp. at the 16S rRNA locus, and 87.8-99.1% similarity at gyrB. Phylogenetic analyses in conjunction with percent sequence identity suggest some of the recovered isolates may represent novel Chryseobacterium subspecies or species. The pathogenicity of 5 isolates was evaluated experimentally in rainbow trout (n = 60), brown trout Salmo trutta (n = 60) and white sturgeon (n = 36) in flow-through freshwater at 18°C. Approximately 107 CFU fish-1 was injected in the epaxial musculature of anesthetized animals. Limited mortality was observed and no bacteria were recovered from dead or moribund fish post-challenge. Thirty days post-challenge, survivors were euthanized and multiple tissues were collected and fixed for histological analysis. No consistent histopathological changes were observed in challenged or control fish. While results suggest the recovered Chryseobacterium spp. may be opportunistic pathogens, further research is warranted to better understand the role of these bacteria in fish disease.

KW - 16S rRNA

KW - Chryseobacterium

KW - Flavobacterium

KW - gyrB

KW - North America

UR - http://www.scopus.com/inward/record.url?scp=85074959021&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85074959021&partnerID=8YFLogxK

U2 - 10.3354/dao03409

DO - 10.3354/dao03409

M3 - Article

C2 - 31724555

AN - SCOPUS:85074959021

VL - 136

SP - 227

EP - 234

JO - Diseases of Aquatic Organisms

JF - Diseases of Aquatic Organisms

SN - 0177-5103

IS - 3

ER -