Co-infection of Atlantic salmon (Salmo salar) by Lepeophtheirus salmonis and Moritella viscosa
A co-infection is defined as an infection with two or more different pathogens, where the pathogens can either have a synergistic or antagonistic effect or alternatively not affect each other at all. Lepeophtheirus salmonis are the single largest problem found in salmonid farming today. It is a mari...
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The University of Bergen
2019
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Online Access: | https://hdl.handle.net/1956/20262 |
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ftunivbergen:oai:bora.uib.no:1956/20262 2023-05-15T15:33:04+02:00 Co-infection of Atlantic salmon (Salmo salar) by Lepeophtheirus salmonis and Moritella viscosa Hauge, Hege Sørvåg 2019-06-19T22:00:17Z application/pdf https://hdl.handle.net/1956/20262 nob nob The University of Bergen https://hdl.handle.net/1956/20262 Copyright the Author. All rights reserved Co-infection Lepeophtheirus salmonis Moritella viscosa 759906 Master thesis 2019 ftunivbergen 2023-03-14T17:43:17Z A co-infection is defined as an infection with two or more different pathogens, where the pathogens can either have a synergistic or antagonistic effect or alternatively not affect each other at all. Lepeophtheirus salmonis are the single largest problem found in salmonid farming today. It is a marine ectoparasitic copepod (Caligidae) occurring on both wild and farmed salmonids in cold temperate waters in the North Atlantic and North Pacific Ocean. They feed on mucus, skin and blood of their host leading to mild skin lesions that can disturb the osmotic balance. Moritella viscosa is a gram-negative bacterium thought to be the main agent causing winter ulcer disease in salmonids and occurs when water temperature is under 10 ºC. Clinical signs are necrosis of the skin, which advance to skin lesions on the flank, ranging from raised scales to larger lesions with exposed muscle tissue. This study looks at the co-infection of L. salmonis and M. viscosa and how these two pathogens affect growth, disease development (lice and ulcer number, size and severity) and transcription of immune genes. Study fish were sampled at four time points: (A) 5 days prior to infection, (B) 6 days post infection (dpi) L. salmonis; 7 dpi L. salmonis and 2 dpi M. viscosa [co-infection] dpi. (C) 26 dpi L. salmonis, 23 dpi M. viscosa [co-infection]. (D) 40 dpi L. salmonis, 37pi M. viscosa [co-infection]. During sampling, weight, length, condition factor (K-factor) was measured; lesions were counted, sized and graded; Lice were counted and staged. Transcription of immune genes Interleukin 1b (IL-1b), Interleukin 4 (IL-4), Interleukin 8 (IL-8), Interleukin 10 (IL-10), complement protein 3 (C3) and Immunoglobulin M (IgM). 2-ΔΔCt were analyzed from sampling B and C in skin and head kidney with Elongation factor α (EFα) as a reference gene. Results showed that a M. viscosa infection (both single and co-infected) did affect weight and k-factor compared to control and L. salmonis., but no differences between a M. viscosa single and co-infection. M. ... Master Thesis Atlantic salmon North Atlantic Salmo salar University of Bergen: Bergen Open Research Archive (BORA-UiB) Pacific |
institution |
Open Polar |
collection |
University of Bergen: Bergen Open Research Archive (BORA-UiB) |
op_collection_id |
ftunivbergen |
language |
Norwegian Bokmål |
topic |
Co-infection Lepeophtheirus salmonis Moritella viscosa 759906 |
spellingShingle |
Co-infection Lepeophtheirus salmonis Moritella viscosa 759906 Hauge, Hege Sørvåg Co-infection of Atlantic salmon (Salmo salar) by Lepeophtheirus salmonis and Moritella viscosa |
topic_facet |
Co-infection Lepeophtheirus salmonis Moritella viscosa 759906 |
description |
A co-infection is defined as an infection with two or more different pathogens, where the pathogens can either have a synergistic or antagonistic effect or alternatively not affect each other at all. Lepeophtheirus salmonis are the single largest problem found in salmonid farming today. It is a marine ectoparasitic copepod (Caligidae) occurring on both wild and farmed salmonids in cold temperate waters in the North Atlantic and North Pacific Ocean. They feed on mucus, skin and blood of their host leading to mild skin lesions that can disturb the osmotic balance. Moritella viscosa is a gram-negative bacterium thought to be the main agent causing winter ulcer disease in salmonids and occurs when water temperature is under 10 ºC. Clinical signs are necrosis of the skin, which advance to skin lesions on the flank, ranging from raised scales to larger lesions with exposed muscle tissue. This study looks at the co-infection of L. salmonis and M. viscosa and how these two pathogens affect growth, disease development (lice and ulcer number, size and severity) and transcription of immune genes. Study fish were sampled at four time points: (A) 5 days prior to infection, (B) 6 days post infection (dpi) L. salmonis; 7 dpi L. salmonis and 2 dpi M. viscosa [co-infection] dpi. (C) 26 dpi L. salmonis, 23 dpi M. viscosa [co-infection]. (D) 40 dpi L. salmonis, 37pi M. viscosa [co-infection]. During sampling, weight, length, condition factor (K-factor) was measured; lesions were counted, sized and graded; Lice were counted and staged. Transcription of immune genes Interleukin 1b (IL-1b), Interleukin 4 (IL-4), Interleukin 8 (IL-8), Interleukin 10 (IL-10), complement protein 3 (C3) and Immunoglobulin M (IgM). 2-ΔΔCt were analyzed from sampling B and C in skin and head kidney with Elongation factor α (EFα) as a reference gene. Results showed that a M. viscosa infection (both single and co-infected) did affect weight and k-factor compared to control and L. salmonis., but no differences between a M. viscosa single and co-infection. M. ... |
format |
Master Thesis |
author |
Hauge, Hege Sørvåg |
author_facet |
Hauge, Hege Sørvåg |
author_sort |
Hauge, Hege Sørvåg |
title |
Co-infection of Atlantic salmon (Salmo salar) by Lepeophtheirus salmonis and Moritella viscosa |
title_short |
Co-infection of Atlantic salmon (Salmo salar) by Lepeophtheirus salmonis and Moritella viscosa |
title_full |
Co-infection of Atlantic salmon (Salmo salar) by Lepeophtheirus salmonis and Moritella viscosa |
title_fullStr |
Co-infection of Atlantic salmon (Salmo salar) by Lepeophtheirus salmonis and Moritella viscosa |
title_full_unstemmed |
Co-infection of Atlantic salmon (Salmo salar) by Lepeophtheirus salmonis and Moritella viscosa |
title_sort |
co-infection of atlantic salmon (salmo salar) by lepeophtheirus salmonis and moritella viscosa |
publisher |
The University of Bergen |
publishDate |
2019 |
url |
https://hdl.handle.net/1956/20262 |
geographic |
Pacific |
geographic_facet |
Pacific |
genre |
Atlantic salmon North Atlantic Salmo salar |
genre_facet |
Atlantic salmon North Atlantic Salmo salar |
op_relation |
https://hdl.handle.net/1956/20262 |
op_rights |
Copyright the Author. All rights reserved |
_version_ |
1766363538316591104 |