A review of infectious gill disease in marine salmonid fish

Mitchell, Susan O.; Rodger, H. D.

doi:10.1111/j.1365-2761.2011.01251.x

Cited by 130 publications

(158 citation statements)

References 95 publications

Supporting

Mentioning

144

Contrasting

Unclassified

Order By: Relevance

“…This method is particularly suitable on Atlantic salmon farms that are constantly affected by the disease, allowing operators to become familiar with the gross presentation of lesions. However, the gross gill score can be difficult to interpret when non-AGD pathologies, such as proliferative gill disease or gill necrosis are present (Steinum et al, 2010;Mitchell and Rodger, 2011). It is also reported that the gross gill scoring method is less applicable for other fish species affected by AGD, such as lumpfish (Cyclopterus lumpus) which are used as cleaner fish in Atlantic salmon cages (Haugland et al, in press).…”

Section: Discussionmentioning

confidence: 99%

Evaluation of Non-destructive Molecular Diagnostics for the Detection of Neoparamoeba perurans

et al. 2017

View full text Add to dashboard Cite

Amoebic gill disease (AGD) caused by Neoparamoeba perurans, has emerged in Europe as a significant problem for the Atlantic salmon farming industry. Gross gill score is the most widely used and practical method for determining AGD severity on farms and informing management decisions on disease mitigation strategies. As molecular diagnosis of AGD remains a high priority for much of the international salmon farming industry, there is a need to evaluate the suitability of currently available molecular assays in conjunction with the most appropriate non-destructive sampling methodology. The aims of this study were to assess a non-destructive sampling methodology (gill swabs) and to compare a range of currently available real-time polymerase chain-reaction (PCR) assays for the detection of N. perurans. Furthermore a comparison of the nondestructive molecular diagnostics with traditional screening methods of gill scoring and histopathology was also undertaken. The study found that all molecular protocols assessed performed well in cases of clinical AGD with high gill scores. A TaqMan based assay (protocol 1) was the optimal assay based on a range of parameters including % positive samples from a field trial performed on fish with gill scores ranging from 0 to 5. A higher proportion of gill swab samples tested positive by all protocols than gill filament biopsies and there was a strong correlation between gill swabs tested by protocol 1 and gross gill score and histology scores. Screening for N. perurans using protocol 1 in conjunction with non-destructive gill swab samples was shown to give the best results.

show abstract

Section: Discussionmentioning

confidence: 99%

Evaluation of Non-destructive Molecular Diagnostics for the Detection of Neoparamoeba perurans

et al. 2017

View full text Add to dashboard Cite

show abstract

“…High salinity (> 32 ppt) and periods of low rainfall strongly correlate with AGD outbreaks (Munday et al 2001, Mitchell & Rodger 2011, Nowak 2012. Further, efficacy of freshwater baths in assuaging AGD infections in salmon (Nowak 2012), along with the crenation, ceased growth and death of N. pemaquidensis cells at low salinities (Lee et al 2006), infer that N. perurans are susceptible to salinity changes.…”

Section: Introductionmentioning

confidence: 99%

Depth distribution of the amoebic gill disease agent, Neoparamoeba perurans, in salmon sea-cages

Wright¹,

Nowak²,

Oppedal³

et al. 2015

Aquacult. Environ. Interact.

View full text Add to dashboard Cite

Identifying where and when parasites occur in farming environments is vital to understand transmission dynamics and develop preventative measures that reduce host−parasite encounters. A major parasite concern for Atlantic salmon farming is Neoparamoeba perurans, a marine amoeba that causes the potentially fatal amoebic gill disease (AGD), for which few control options exist. We explored whether free-living N. perurans abundance differs among depths in commercial Atlantic salmon Salmo salar sea-cages. Water samples collected from the surface to 10 m depth at multiple cage sites and times, and subsequently subjected to qPCR analysis, revealed that N. perurans abundance was influenced by depth at the time of year when amoeba numbers were highest, with more amoebae in surface waters. No distinct depth patterns were observed when amoebae were in low abundance. Across all times, temperature and salinity were largely homogeneous throughout cage depths. Possible factors explaining the presence of amoebae at the surface are discussed. Our results suggest that excluding caged salmon from upper cage depths where N. perurans is more abundant could be an effective management strategy to reduce the speed at which initial infections occur and delay the development of AGD outbreaks.

show abstract

“…The clinical and histologic signs of diseased fish were similar to those of AGD in other species reported previously. 7,10 In PCR assays, all samples (3 fish) showed specific N. perurans 636-bp fragments. When these PCR products of N. perurans-positive samples were sequenced, nucleotide sequences of these isolates from black seabream (BSBGoH15) and rock bream (RBGoH15) showed 98.3% sequence identities to each other.…”

Section: Research-article2017mentioning

confidence: 99%

“…Scophthalmus maximus), European seabass (Dicentrarchus labrax), sharpsnout seabream (Diplodus puntazzo), ballan wrasse (Labrus bergylta), and ayu (Plecoglossus altivelis) in Spain, South Africa, the Mediterranean, Norway, and Japan. [1][2][3][7][8][9] Thus, AGD threatens the marine farming industry in many countries.The clinical signs of AGD include multiple white-to-gray patches on swollen gills, with excess mucus surrounding gill arches. 7 The main histologic feature of AGD is prominent epithelial hyperplasia in the gills, resulting in complete lamellar fusion.…”

mentioning

confidence: 99%

Amoebic gill disease outbreak in marine fish cultured in Korea

et al. 2017

View full text Add to dashboard Cite

Brief CommunicationAmoebic gill disease (AGD) is a serious parasitic disease that affects marine cultured salmonids including Atlantic salmon (Salmo salar), coho salmon (Oncorhynchus kisutch), and rainbow trout (Oncorhynchus mykiss) in Australia, the United States, and several European countries. 7-10 AGD also affects other fish species cultured in marine environments, including turbot (Psetta maxima; syn. Scophthalmus maximus), European seabass (Dicentrarchus labrax), sharpsnout seabream (Diplodus puntazzo), ballan wrasse (Labrus bergylta), and ayu (Plecoglossus altivelis) in Spain, South Africa, the Mediterranean, Norway, and Japan. [1][2][3][7][8][9] Thus, AGD threatens the marine farming industry in many countries.The clinical signs of AGD include multiple white-to-gray patches on swollen gills, with excess mucus surrounding gill arches. 7 The main histologic feature of AGD is prominent epithelial hyperplasia in the gills, resulting in complete lamellar fusion. 7,10 Neoparamoeba perurans, Neoparamoeba pemaquidensis, and Neoparamoeba branchiphila have been isolated from or detected in marine fish with AGD. 7,9 Of these amoebae, N. perurans is known as a cosmopolitan etiologic agent of AGD. 14 AGD had not been reported in marine fish in far east Asia until 1994. In 1995, amoebic infection was reported in cultured olive flounder (syn. Japanese flounder; Paralichthys olivaceus) in Korea. 4 Since then, AGD has been found in cultured ayu in 2008 in Japan 1 and coho salmon in 2014 in Korea. 6 We report herein amoebic infection in the following 3 new marine fish species that are cultured in Korea: black seabream (syn. black porgy; Acanthopagrus schlegelii), rock bream (syn. barred knifejaw; Oplegnathus fasciatus), and gray mullet (syn. flathead mullet; Mugil cephalus).In 2015, 6.7-60% mortality was observed in black seabream, rock bream, and mullet farmed on the southern coast of Korea. Black seabream and rock bream were cultured in a farm (land-based system) located in Goheung County. Gray mullet were cultured in a farm (net cage system) located in Hadong County. A total of 21 diseased fish (10 black seabream, weight: 119 ± 29 g; 7 rock bream, 62 ± 23 g; and 4 mullet, 128 ± 23 g) were collected and individually subjected to parasitologic, bacteriologic, and virologic examinations. Gills and body surface were microscopically examined for parasites. Kidney, spleen, and liver were cultured on brainheart infusion agar a plates supplemented with 1% NaCl and incubated at 15°C for 14 d. Kidney and spleen samples were homogenized in 10 volumes of Hanks balanced salt solution b and centrifuged at 3,000 × g for 20 min. The supernatant was filtered through a 450-nm membrane filter. One-hundred microliters of the filtrate was inoculated onto Chinook salmon embryo (CHSE-214) and fathead minnow (FHM) cells in Abstract. In 2015, 6.7-60% mortality was observed in black seabream (Acanthopagrus schlegelii), rock bream (Oplegnathus fasciatus), and gray mullet (Mugil cephalus) farmed in the southern coast of Korea. On examination, num...

show abstract

A review of infectious gill disease in marine salmonid fish

Cited by 130 publications

References 95 publications

Evaluation of Non-destructive Molecular Diagnostics for the Detection of Neoparamoeba perurans

Evaluation of Non-destructive Molecular Diagnostics for the Detection of Neoparamoeba perurans

Depth distribution of the amoebic gill disease agent, Neoparamoeba perurans, in salmon sea-cages

Amoebic gill disease outbreak in marine fish cultured in Korea

Contact Info

Product

Resources

About