Cyclic Hypoxia Exposure Accelerates the Progression of Amoebic Gill Disease
Amoebic gill disease (AGD), caused by the amoeba Neoparamoeba perurans , has led to considerable economic losses in every major Atlantic salmon producing country, and is increasing in frequency. The most serious infections occur during summer and autumn, when temperatures are high and poor dissolved...
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ftdoajarticles:oai:doaj.org/article:f0036cc5397949dc88371b252d3fe373 2023-05-15T15:31:41+02:00 Cyclic Hypoxia Exposure Accelerates the Progression of Amoebic Gill Disease Tina Oldham Tim Dempster Philip Crosbie Mark Adams Barbara Nowak 2020-07-01T00:00:00Z https://doi.org/10.3390/pathogens9080597 https://doaj.org/article/f0036cc5397949dc88371b252d3fe373 EN eng MDPI AG https://www.mdpi.com/2076-0817/9/8/597 https://doaj.org/toc/2076-0817 doi:10.3390/pathogens9080597 2076-0817 https://doaj.org/article/f0036cc5397949dc88371b252d3fe373 Pathogens, Vol 9, Iss 597, p 597 (2020) Salmo salar Atlantic salmon aquaculture dissolved oxygen Paramoeba/Neoparamoeba perurans stress Medicine R article 2020 ftdoajarticles https://doi.org/10.3390/pathogens9080597 2022-12-30T20:00:32Z Amoebic gill disease (AGD), caused by the amoeba Neoparamoeba perurans , has led to considerable economic losses in every major Atlantic salmon producing country, and is increasing in frequency. The most serious infections occur during summer and autumn, when temperatures are high and poor dissolved oxygen (DO) conditions are most common. Here, we tested if exposure to cyclic hypoxia at DO saturations of 40–60% altered the course of infection with N. perurans compared to normoxic controls maintained at ≥90% DO saturation. Although hypoxia exposure did not increase initial susceptibility to N. perurans , it accelerated progression of the disease. By 7 days post-inoculation, amoeba counts estimated from qPCR analysis were 1.7 times higher in the hypoxic treatment than in normoxic controls, and cumulative mortalities were twice as high (16 ± 4% and 8 ± 2%), respectively. At 10 days post-inoculation, however, there were no differences between amoeba counts in the hypoxic and normoxic treatments, nor in the percentage of filaments with AGD lesions (control = 74 ± 2.8%, hypoxic = 69 ± 3.3%), or number of lamellae per lesion (control = 30 ± 0.9%, hypoxic = 27.9 ± 0.9%) as determined by histological examination. Cumulative mortalities at the termination of the experiment were similarly high in both treatments (hypoxic = 60 ± 2%, normoxic = 53 ± 11%). These results reveal that exposure to cyclic hypoxia in a diel pattern, equivalent to what salmon are exposed to in marine aquaculture cages, accelerated the progression of AGD in post-smolts. Article in Journal/Newspaper Atlantic salmon Salmo salar Directory of Open Access Journals: DOAJ Articles Pathogens 9 8 597 |
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Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Salmo salar Atlantic salmon aquaculture dissolved oxygen Paramoeba/Neoparamoeba perurans stress Medicine R |
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Salmo salar Atlantic salmon aquaculture dissolved oxygen Paramoeba/Neoparamoeba perurans stress Medicine R Tina Oldham Tim Dempster Philip Crosbie Mark Adams Barbara Nowak Cyclic Hypoxia Exposure Accelerates the Progression of Amoebic Gill Disease |
topic_facet |
Salmo salar Atlantic salmon aquaculture dissolved oxygen Paramoeba/Neoparamoeba perurans stress Medicine R |
description |
Amoebic gill disease (AGD), caused by the amoeba Neoparamoeba perurans , has led to considerable economic losses in every major Atlantic salmon producing country, and is increasing in frequency. The most serious infections occur during summer and autumn, when temperatures are high and poor dissolved oxygen (DO) conditions are most common. Here, we tested if exposure to cyclic hypoxia at DO saturations of 40–60% altered the course of infection with N. perurans compared to normoxic controls maintained at ≥90% DO saturation. Although hypoxia exposure did not increase initial susceptibility to N. perurans , it accelerated progression of the disease. By 7 days post-inoculation, amoeba counts estimated from qPCR analysis were 1.7 times higher in the hypoxic treatment than in normoxic controls, and cumulative mortalities were twice as high (16 ± 4% and 8 ± 2%), respectively. At 10 days post-inoculation, however, there were no differences between amoeba counts in the hypoxic and normoxic treatments, nor in the percentage of filaments with AGD lesions (control = 74 ± 2.8%, hypoxic = 69 ± 3.3%), or number of lamellae per lesion (control = 30 ± 0.9%, hypoxic = 27.9 ± 0.9%) as determined by histological examination. Cumulative mortalities at the termination of the experiment were similarly high in both treatments (hypoxic = 60 ± 2%, normoxic = 53 ± 11%). These results reveal that exposure to cyclic hypoxia in a diel pattern, equivalent to what salmon are exposed to in marine aquaculture cages, accelerated the progression of AGD in post-smolts. |
format |
Article in Journal/Newspaper |
author |
Tina Oldham Tim Dempster Philip Crosbie Mark Adams Barbara Nowak |
author_facet |
Tina Oldham Tim Dempster Philip Crosbie Mark Adams Barbara Nowak |
author_sort |
Tina Oldham |
title |
Cyclic Hypoxia Exposure Accelerates the Progression of Amoebic Gill Disease |
title_short |
Cyclic Hypoxia Exposure Accelerates the Progression of Amoebic Gill Disease |
title_full |
Cyclic Hypoxia Exposure Accelerates the Progression of Amoebic Gill Disease |
title_fullStr |
Cyclic Hypoxia Exposure Accelerates the Progression of Amoebic Gill Disease |
title_full_unstemmed |
Cyclic Hypoxia Exposure Accelerates the Progression of Amoebic Gill Disease |
title_sort |
cyclic hypoxia exposure accelerates the progression of amoebic gill disease |
publisher |
MDPI AG |
publishDate |
2020 |
url |
https://doi.org/10.3390/pathogens9080597 https://doaj.org/article/f0036cc5397949dc88371b252d3fe373 |
genre |
Atlantic salmon Salmo salar |
genre_facet |
Atlantic salmon Salmo salar |
op_source |
Pathogens, Vol 9, Iss 597, p 597 (2020) |
op_relation |
https://www.mdpi.com/2076-0817/9/8/597 https://doaj.org/toc/2076-0817 doi:10.3390/pathogens9080597 2076-0817 https://doaj.org/article/f0036cc5397949dc88371b252d3fe373 |
op_doi |
https://doi.org/10.3390/pathogens9080597 |
container_title |
Pathogens |
container_volume |
9 |
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8 |
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597 |
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