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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ftpubmed:oai:pubmedcentral.nih.gov:7460382 2023-05-15T15:32:32+02:00 Cyclic Hypoxia Exposure Accelerates the Progression of Amoebic Gill Disease Oldham, Tina Dempster, Tim Crosbie, Philip Adams, Mark Nowak, Barbara 2020-07-22 http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7460382/ http://www.ncbi.nlm.nih.gov/pubmed/32707755 https://doi.org/10.3390/pathogens9080597 en eng MDPI http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7460382/ http://www.ncbi.nlm.nih.gov/pubmed/32707755 http://dx.doi.org/10.3390/pathogens9080597 © 2020 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/). CC-BY Pathogens Article Text 2020 ftpubmed https://doi.org/10.3390/pathogens9080597 2020-09-06T00:55:25Z 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. Text Atlantic salmon PubMed Central (PMC) Pathogens 9 8 597 |
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Article Oldham, Tina Dempster, Tim Crosbie, Philip Adams, Mark Nowak, Barbara Cyclic Hypoxia Exposure Accelerates the Progression of Amoebic Gill Disease |
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Article |
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 |
Text |
author |
Oldham, Tina Dempster, Tim Crosbie, Philip Adams, Mark Nowak, Barbara |
author_facet |
Oldham, Tina Dempster, Tim Crosbie, Philip Adams, Mark Nowak, Barbara |
author_sort |
Oldham, Tina |
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 |
publishDate |
2020 |
url |
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7460382/ http://www.ncbi.nlm.nih.gov/pubmed/32707755 https://doi.org/10.3390/pathogens9080597 |
genre |
Atlantic salmon |
genre_facet |
Atlantic salmon |
op_source |
Pathogens |
op_relation |
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7460382/ http://www.ncbi.nlm.nih.gov/pubmed/32707755 http://dx.doi.org/10.3390/pathogens9080597 |
op_rights |
© 2020 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/). |
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CC-BY |
op_doi |
https://doi.org/10.3390/pathogens9080597 |
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Pathogens |
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