The Experts below are selected from a list of 168 Experts worldwide ranked by ideXlab platform
Mark D. Powell - One of the best experts on this subject based on the ideXlab platform.
-
In vitro toxicity of Bithionol and Bithionol sulphoxide to Neoparamoeba spp., the causative agent of amoebic gill disease (AGD).
Diseases of aquatic organisms, 2010Co-Authors: Renee L Florent, Joy A. Becker, Mark D. PowellAbstract:The objective of the present study was to evaluate the in vitro toxicity of Bithionol and Bithionol sulphoxide to Neoparamoeba spp., the causative agent of amoebic gill disease (AGD). The current treatment for AGD-affected Atlantic salmon involves bathing sea-caged fish in freshwater for a minimum of 3 h, a labour-intensive and costly exercise. Previous attempts to identify alternative treatments have suggested Bithionol as an alternate therapeutic, but extensive in vitro efficacy test- ing has not yet been done. In vitro toxicity to Neoparamoeba spp. was examined using amoebae iso- lated from the gill of AGD-affected Atlantic salmon and exposing the parasites to freshwater, alumina (10 mg l -1 ), seawater, Bithionol or Bithionol sulphoxide at nominal concentrations of 0.1, 0.5, 1, 5 and 10 mg l -1 in seawater. The numbers of viable amoebae were counted using the trypan blue exclusion method at 0, 24, 48 and 72 h. Both Bithionol and Bithionol sulphoxide demonstrated in vitro toxicity to Neoparamoeba spp. at all concentrations examined (0.1 to 10 mg l -1 over 72 h), with a comparable toxicity to freshwater observed for both chemicals at concentrations >5 mg l -1 following a 72 h treat- ment. Freshwater remained the most effective treatment, with only 6% viable amoebae seen after 24 h and no viable amoebae observed after 48 h.
-
Further development of Bithionol therapy as a treatment for amoebic gill disease in Atlantic salmon, Salmo salar L.
Journal of fish diseases, 2009Co-Authors: Renee L Florent, Joy A. Becker, Mark D. PowellAbstract:This study examined the efficacy of Bithionol as a prophylactic or therapeutic oral treatment for Atlantic salmon (AS), Salmo salar, affected by amoebic gill disease (AGD). Furthermore, it explored the interaction of Bithionol oral therapy with the current standard treatment (a freshwater bath for at least 3 h). The efficacy of three medicated feeds was determined in the trial by feeding AGDaffected AS at 1% body weight (BW) day )1 either oil coated commercial feed (control) or prophylactic and therapeutic Bithionol at 25 mg kg )1 feed. Feeding commenced 2 weeks prior to exposure to Neoparamoeba spp. at 300 cells L )1 and continued for 49 days post-exposure (PE). Bithionol when fed as a 2-week prophylactic or therapeutic treatment at 25 mg kg )1 feed delayed the onset of AGD pathology and reduced the percentage of gill filaments with lesions. Administration of a 3-h freshwater bath at 28 days PE significantly reduced amoeba numbers to a similar level across all treatments; in contrast, gross gill score and percent lesioned filaments were reduced to different extents, the control having a significantly higher score than both Bithionol treatments. Following the freshwater bath, clinical signs of AGD increased at a similar level across all treatments, albeit controls were significantly higher than the Bithionol treatments immediately following freshwater treatment. This study demonstrated that Bithionol at 25 mg kg )1 feed, when fed as a 2-week prophylactic or a therapeutic treatment, delayed and reduced the intensity of AGD pathology and warrants further investigation as a treatment for AGD-affected AS.
-
Efficacy of Bithionol as an oral treatment for amoebic gill disease in Atlantic salmon Salmo salar (L.)
Aquaculture, 2007Co-Authors: Renee L Florent, Joy A. Becker, Mark D. PowellAbstract:This study examined the efficacy of Bithionol as an oral treatment for Atlantic salmon Salmo salar affected by amoebic gill disease (AGD). The current commercial management strategy of AGD is a costly 3 h freshwater bath. It is labour intensive and the number of baths needed appears to be increasing; hence, there is an effort to identify alternative treatments. Efficacy was examined by feeding AGD-affected Atlantic salmon twice daily to satiation with Bithionol, an antiprotozoal, at 25 mg kg −1 feed. Three seawater (35‰, 17 °C) re-circulation systems were used each consisting of three tanks containing 32 Atlantic salmon smolts with an average (±SEM) mass of 90.4 g (±5.2). Three feeds were examined in the trial including Bithionol, plain commercial control and oil coated commercial control. Feeding commenced 2 weeks prior to exposure to Neoparamoeba spp. at 300 cells L −1 and continued for 28 days post-exposure. Efficacy was determined by examining gross gill score and identifying percent lesioned gill filaments twice weekly for 4 weeks post-exposure. Bithionol when fed as a two-week prophylactic treatment at 25 mg kg −1 feed delayed the onset of AGD pathology and reduced the percent lesioned gill filaments by 53% and halved the gill score from 2 to 1 when compared with both the plain and oil controls during an experimental challenge. There were no palatability problems observed with mean feed intake of Bithionol over the trial duration with fish consuming higher levels of the Bithionol diet compared to both the oil and plain controls. This study demonstrated that Bithionol at 25 mg kg −1 feed, when fed as a two-week prophylactic treatment for Neoparamoeba spp. exposure, delayed and reduced the intensity of AGD pathology and warrants further investigation as an alternative to the current freshwater bath treatment for AGD-affected Atlantic salmon. © 2007 Elsevier B.V. All rights reserved.
-
Efficacy of Bithionol as an oral treatment for amoebic gill disease in Atlantic salmon Salmo salar (L.)
Aquaculture, 2007Co-Authors: Renee L Florent, Joy A. Becker, Mark D. PowellAbstract:This study examined the efficacy of Bithionol as an oral treatment for Atlantic salmon Salmo salar affected by amoebic gill disease (AGD). The current commercial management strategy of AGD is a costly 3 h freshwater bath. It is labour intensive and the number of baths needed appears to be increasing; hence, there is an effort to identify alternative treatments. Efficacy was examined by feeding AGD-affected Atlantic salmon twice daily to satiation with Bithionol, an antiprotozoal, at 25 mg kg−1 feed. Three seawater (35‰, 17 °C) re-circulation systems were used each consisting of three tanks containing 32 Atlantic salmon smolts with an average (±SEM) mass of 90.4 g (±5.2). Three feeds were examined in the trial including Bithionol, plain commercial control and oil coated commercial control. Feeding commenced 2 weeks prior to exposure to Neoparamoeba spp. at 300 cells L−1 and continued for 28 days post-exposure. Efficacy was determined by examining gross gill score and identifying percent lesioned gill filaments twice weekly for 4 weeks post-exposure. Bithionol when fed as a two-week prophylactic treatment at 25 mg kg−1 feed delayed the onset of AGD pathology and reduced the percent lesioned gill filaments by 53% and halved the gill score from 2 to 1 when compared with both the plain and oil controls during an experimental challenge. There were no palatability problems observed with mean feed intake of Bithionol over the trial duration with fish consuming higher levels of the Bithionol diet compared to both the oil and plain controls. This study demonstrated that Bithionol at 25 mg kg−1 feed, when fed as a two-week prophylactic treatment for Neoparamoeba spp. exposure, delayed and reduced the intensity of AGD pathology and warrants further investigation as an alternative to the current freshwater bath treatment for AGD-affected Atlantic salmon
-
Evaluation of Bithionol as a bath treatment for amoebic gill disease caused by Neoparamoeba spp.
Veterinary parasitology, 2006Co-Authors: Renee L Florent, Joy A. Becker, Mark D. PowellAbstract:This study examined the toxicity of Bithionol to Atlantic salmon Salmo salar and rainbow trout Oncorhynchus mykiss in fresh- and seawater and the efficacy of Bithionol as a 1h seawater bath treatment for amoebic gill disease (AGD). To examine toxicity, fish were bathed for 1, 3 and 6h in Bithionol, an anti-protozoal at 0, 1, 5, 10, 25 and 35mgL(-1) with toxicity determined by time to morbidity. Efficacy was examined by bathing AGD-affected Atlantic salmon and rainbow trout for 1h at Bithionol concentrations of 1-25mgL(-1). Efficacy was determined by examining gill amoeba counts and identifying percent lesioned gill filaments at 1 and 24h after bath exposure to Bithionol. For both species, Bithionol was determined to be toxic at 25 and 35mgL(-1) exhibiting median lethal times (LT50s) ranging from 21 to 84min. Morbidity occurred in the 5 and 10mgL(-1) treatments, however, due to sampling regime there were not enough fish available to calculate LT50s. Only Bithionol at 1mgL(-1) was considered non-toxic with no signs of morbidity. Bithionol was more toxic in seawater than freshwater and had no acute effects on gill Na+/K+ ATPase and succinic dehydrogenase, or plasma osmolality and chloride concentration. Bithionol at 1mgL(-1) reduced percent lesioned gill filaments in Atlantic salmon and rainbow trout by 33 and 27 per cent, respectively, compared to the seawater control. Similarly, numbers of amoeba were reduced by 33 and 43 per cent for Atlantic salmon and rainbow trout, respectively, when compared to the seawater control. Furthermore, Bithionol reduced percent lesioned gill filaments as much as did the current industry standard of freshwater. This study demonstrated that a 1h seawater bath containing 1mgL(-1) Bithionol could be an improvement to the current method of treatment for AGD-affected Atlantic salmon and rainbow trout.
Kang Kai - One of the best experts on this subject based on the ideXlab platform.
-
Investigation on Determination of Tungsten in Spongy Zirconium —— Zinc- Bithionol- Chloroform Extracting Spectrophotometric Method
Nuclear Power Engineering, 2001Co-Authors: Kang KaiAbstract:： Determination of tungsten in spongy zirconium by zinc- Bithionol- chloroform extracting spectrophotometric method was investigated in detail,including the synthetic process of zinc- Bithionol,and the optimized test conditions and/or parameters.After dissolved in HCl＋ HF mixture acid,tungsten of high valence state in spongy zirconium samples was then reduced to its lower valence state form by TiCl3 in hydrochloride acid medium,at (95± 2)℃ .Finally,the resultant was allowed to react with zinc- Bithionol,obtaining a green blue complex which was extracted by chloroform and tested by spectro- photometric method.The recycling ratio and the relative standard deviation as well as the determination scope of this method were 98％～ 100％ ,10％ ,and 0.5～ 200μ g/g,respectively.
-
investigation on determination of tungsten in spongy zirconium zinc Bithionol chloroform extracting spectrophotometric method
Nuclear Power Engineering, 2001Co-Authors: Kang KaiAbstract:： Determination of tungsten in spongy zirconium by zinc- Bithionol- chloroform extracting spectrophotometric method was investigated in detail,including the synthetic process of zinc- Bithionol,and the optimized test conditions and/or parameters.After dissolved in HCl＋ HF mixture acid,tungsten of high valence state in spongy zirconium samples was then reduced to its lower valence state form by TiCl3 in hydrochloride acid medium,at (95± 2)℃ .Finally,the resultant was allowed to react with zinc- Bithionol,obtaining a green blue complex which was extracted by chloroform and tested by spectro- photometric method.The recycling ratio and the relative standard deviation as well as the determination scope of this method were 98％～ 100％ ,10％ ,and 0.5～ 200μ g/g,respectively.
Renee L Florent - One of the best experts on this subject based on the ideXlab platform.
-
In vitro toxicity of Bithionol and Bithionol sulphoxide to Neoparamoeba spp., the causative agent of amoebic gill disease (AGD).
Diseases of aquatic organisms, 2010Co-Authors: Renee L Florent, Joy A. Becker, Mark D. PowellAbstract:The objective of the present study was to evaluate the in vitro toxicity of Bithionol and Bithionol sulphoxide to Neoparamoeba spp., the causative agent of amoebic gill disease (AGD). The current treatment for AGD-affected Atlantic salmon involves bathing sea-caged fish in freshwater for a minimum of 3 h, a labour-intensive and costly exercise. Previous attempts to identify alternative treatments have suggested Bithionol as an alternate therapeutic, but extensive in vitro efficacy test- ing has not yet been done. In vitro toxicity to Neoparamoeba spp. was examined using amoebae iso- lated from the gill of AGD-affected Atlantic salmon and exposing the parasites to freshwater, alumina (10 mg l -1 ), seawater, Bithionol or Bithionol sulphoxide at nominal concentrations of 0.1, 0.5, 1, 5 and 10 mg l -1 in seawater. The numbers of viable amoebae were counted using the trypan blue exclusion method at 0, 24, 48 and 72 h. Both Bithionol and Bithionol sulphoxide demonstrated in vitro toxicity to Neoparamoeba spp. at all concentrations examined (0.1 to 10 mg l -1 over 72 h), with a comparable toxicity to freshwater observed for both chemicals at concentrations >5 mg l -1 following a 72 h treat- ment. Freshwater remained the most effective treatment, with only 6% viable amoebae seen after 24 h and no viable amoebae observed after 48 h.
-
Further development of Bithionol therapy as a treatment for amoebic gill disease in Atlantic salmon, Salmo salar L.
Journal of fish diseases, 2009Co-Authors: Renee L Florent, Joy A. Becker, Mark D. PowellAbstract:This study examined the efficacy of Bithionol as a prophylactic or therapeutic oral treatment for Atlantic salmon (AS), Salmo salar, affected by amoebic gill disease (AGD). Furthermore, it explored the interaction of Bithionol oral therapy with the current standard treatment (a freshwater bath for at least 3 h). The efficacy of three medicated feeds was determined in the trial by feeding AGDaffected AS at 1% body weight (BW) day )1 either oil coated commercial feed (control) or prophylactic and therapeutic Bithionol at 25 mg kg )1 feed. Feeding commenced 2 weeks prior to exposure to Neoparamoeba spp. at 300 cells L )1 and continued for 49 days post-exposure (PE). Bithionol when fed as a 2-week prophylactic or therapeutic treatment at 25 mg kg )1 feed delayed the onset of AGD pathology and reduced the percentage of gill filaments with lesions. Administration of a 3-h freshwater bath at 28 days PE significantly reduced amoeba numbers to a similar level across all treatments; in contrast, gross gill score and percent lesioned filaments were reduced to different extents, the control having a significantly higher score than both Bithionol treatments. Following the freshwater bath, clinical signs of AGD increased at a similar level across all treatments, albeit controls were significantly higher than the Bithionol treatments immediately following freshwater treatment. This study demonstrated that Bithionol at 25 mg kg )1 feed, when fed as a 2-week prophylactic or a therapeutic treatment, delayed and reduced the intensity of AGD pathology and warrants further investigation as a treatment for AGD-affected AS.
-
Efficacy of Bithionol as an oral treatment for amoebic gill disease in Atlantic salmon Salmo salar (L.)
Aquaculture, 2007Co-Authors: Renee L Florent, Joy A. Becker, Mark D. PowellAbstract:This study examined the efficacy of Bithionol as an oral treatment for Atlantic salmon Salmo salar affected by amoebic gill disease (AGD). The current commercial management strategy of AGD is a costly 3 h freshwater bath. It is labour intensive and the number of baths needed appears to be increasing; hence, there is an effort to identify alternative treatments. Efficacy was examined by feeding AGD-affected Atlantic salmon twice daily to satiation with Bithionol, an antiprotozoal, at 25 mg kg −1 feed. Three seawater (35‰, 17 °C) re-circulation systems were used each consisting of three tanks containing 32 Atlantic salmon smolts with an average (±SEM) mass of 90.4 g (±5.2). Three feeds were examined in the trial including Bithionol, plain commercial control and oil coated commercial control. Feeding commenced 2 weeks prior to exposure to Neoparamoeba spp. at 300 cells L −1 and continued for 28 days post-exposure. Efficacy was determined by examining gross gill score and identifying percent lesioned gill filaments twice weekly for 4 weeks post-exposure. Bithionol when fed as a two-week prophylactic treatment at 25 mg kg −1 feed delayed the onset of AGD pathology and reduced the percent lesioned gill filaments by 53% and halved the gill score from 2 to 1 when compared with both the plain and oil controls during an experimental challenge. There were no palatability problems observed with mean feed intake of Bithionol over the trial duration with fish consuming higher levels of the Bithionol diet compared to both the oil and plain controls. This study demonstrated that Bithionol at 25 mg kg −1 feed, when fed as a two-week prophylactic treatment for Neoparamoeba spp. exposure, delayed and reduced the intensity of AGD pathology and warrants further investigation as an alternative to the current freshwater bath treatment for AGD-affected Atlantic salmon. © 2007 Elsevier B.V. All rights reserved.
-
Efficacy of Bithionol as an oral treatment for amoebic gill disease in Atlantic salmon Salmo salar (L.)
Aquaculture, 2007Co-Authors: Renee L Florent, Joy A. Becker, Mark D. PowellAbstract:This study examined the efficacy of Bithionol as an oral treatment for Atlantic salmon Salmo salar affected by amoebic gill disease (AGD). The current commercial management strategy of AGD is a costly 3 h freshwater bath. It is labour intensive and the number of baths needed appears to be increasing; hence, there is an effort to identify alternative treatments. Efficacy was examined by feeding AGD-affected Atlantic salmon twice daily to satiation with Bithionol, an antiprotozoal, at 25 mg kg−1 feed. Three seawater (35‰, 17 °C) re-circulation systems were used each consisting of three tanks containing 32 Atlantic salmon smolts with an average (±SEM) mass of 90.4 g (±5.2). Three feeds were examined in the trial including Bithionol, plain commercial control and oil coated commercial control. Feeding commenced 2 weeks prior to exposure to Neoparamoeba spp. at 300 cells L−1 and continued for 28 days post-exposure. Efficacy was determined by examining gross gill score and identifying percent lesioned gill filaments twice weekly for 4 weeks post-exposure. Bithionol when fed as a two-week prophylactic treatment at 25 mg kg−1 feed delayed the onset of AGD pathology and reduced the percent lesioned gill filaments by 53% and halved the gill score from 2 to 1 when compared with both the plain and oil controls during an experimental challenge. There were no palatability problems observed with mean feed intake of Bithionol over the trial duration with fish consuming higher levels of the Bithionol diet compared to both the oil and plain controls. This study demonstrated that Bithionol at 25 mg kg−1 feed, when fed as a two-week prophylactic treatment for Neoparamoeba spp. exposure, delayed and reduced the intensity of AGD pathology and warrants further investigation as an alternative to the current freshwater bath treatment for AGD-affected Atlantic salmon
-
Evaluation of Bithionol as a bath treatment for amoebic gill disease caused by Neoparamoeba spp.
Veterinary parasitology, 2006Co-Authors: Renee L Florent, Joy A. Becker, Mark D. PowellAbstract:This study examined the toxicity of Bithionol to Atlantic salmon Salmo salar and rainbow trout Oncorhynchus mykiss in fresh- and seawater and the efficacy of Bithionol as a 1h seawater bath treatment for amoebic gill disease (AGD). To examine toxicity, fish were bathed for 1, 3 and 6h in Bithionol, an anti-protozoal at 0, 1, 5, 10, 25 and 35mgL(-1) with toxicity determined by time to morbidity. Efficacy was examined by bathing AGD-affected Atlantic salmon and rainbow trout for 1h at Bithionol concentrations of 1-25mgL(-1). Efficacy was determined by examining gill amoeba counts and identifying percent lesioned gill filaments at 1 and 24h after bath exposure to Bithionol. For both species, Bithionol was determined to be toxic at 25 and 35mgL(-1) exhibiting median lethal times (LT50s) ranging from 21 to 84min. Morbidity occurred in the 5 and 10mgL(-1) treatments, however, due to sampling regime there were not enough fish available to calculate LT50s. Only Bithionol at 1mgL(-1) was considered non-toxic with no signs of morbidity. Bithionol was more toxic in seawater than freshwater and had no acute effects on gill Na+/K+ ATPase and succinic dehydrogenase, or plasma osmolality and chloride concentration. Bithionol at 1mgL(-1) reduced percent lesioned gill filaments in Atlantic salmon and rainbow trout by 33 and 27 per cent, respectively, compared to the seawater control. Similarly, numbers of amoeba were reduced by 33 and 43 per cent for Atlantic salmon and rainbow trout, respectively, when compared to the seawater control. Furthermore, Bithionol reduced percent lesioned gill filaments as much as did the current industry standard of freshwater. This study demonstrated that a 1h seawater bath containing 1mgL(-1) Bithionol could be an improvement to the current method of treatment for AGD-affected Atlantic salmon and rainbow trout.
Jeffrey L. Brodsky - One of the best experts on this subject based on the ideXlab platform.
-
A Screen for Modulators of Large T Antigen's ATPase Activity Uncovers Novel Inhibitors of Simian Virus 40 and BK Virus Replication
Antiviral research, 2012Co-Authors: Sandlin P. Seguin, Alex W. Ireland, Tushar Gupta, Christine M. Wright, Yoshinari Miyata, Peter Wipf, James M. Pipas, Jason E. Gestwicki, Jeffrey L. BrodskyAbstract:New polyomaviruses are continually being identified, and it is likely that links between this virus family and disease will continue to emerge. Unfortunately, a specific treatment for polyomavirus-associated disease is lacking. Because polyomaviruses express large Tumor Antigen, TAg, we hypothesized that small molecule inhibitors of the essential ATPase activity of TAg would inhibit viral replication. Using a new screening platform, we identified inhibitors of TAg's ATPase activity. Lead compounds were moved into a secondary assay, and ultimately two FDA approved compounds, Bithionol and hexachlorophene, were identified as the most potent TAg inhibitors known to date. Both compounds inhibited Simian Virus 40 replication as assessed by plaque assay and quantitative PCR. Moreover, these compounds inhibited BK virus, which causes BKV Associated Nephropathy. In neither case was host cell viability compromised at these concentrations. Our data indicate that directed screening for TAg inhibitors is a viable method to identify polyomavirus inhibitors, and that Bithionol and hexachlorophene represent lead compounds that may be further modified and/or ultimately used to combat diseases associated with polyomavirus infection.
Joy A. Becker - One of the best experts on this subject based on the ideXlab platform.
-
In vitro toxicity of Bithionol and Bithionol sulphoxide to Neoparamoeba spp., the causative agent of amoebic gill disease (AGD).
Diseases of aquatic organisms, 2010Co-Authors: Renee L Florent, Joy A. Becker, Mark D. PowellAbstract:The objective of the present study was to evaluate the in vitro toxicity of Bithionol and Bithionol sulphoxide to Neoparamoeba spp., the causative agent of amoebic gill disease (AGD). The current treatment for AGD-affected Atlantic salmon involves bathing sea-caged fish in freshwater for a minimum of 3 h, a labour-intensive and costly exercise. Previous attempts to identify alternative treatments have suggested Bithionol as an alternate therapeutic, but extensive in vitro efficacy test- ing has not yet been done. In vitro toxicity to Neoparamoeba spp. was examined using amoebae iso- lated from the gill of AGD-affected Atlantic salmon and exposing the parasites to freshwater, alumina (10 mg l -1 ), seawater, Bithionol or Bithionol sulphoxide at nominal concentrations of 0.1, 0.5, 1, 5 and 10 mg l -1 in seawater. The numbers of viable amoebae were counted using the trypan blue exclusion method at 0, 24, 48 and 72 h. Both Bithionol and Bithionol sulphoxide demonstrated in vitro toxicity to Neoparamoeba spp. at all concentrations examined (0.1 to 10 mg l -1 over 72 h), with a comparable toxicity to freshwater observed for both chemicals at concentrations >5 mg l -1 following a 72 h treat- ment. Freshwater remained the most effective treatment, with only 6% viable amoebae seen after 24 h and no viable amoebae observed after 48 h.
-
Further development of Bithionol therapy as a treatment for amoebic gill disease in Atlantic salmon, Salmo salar L.
Journal of fish diseases, 2009Co-Authors: Renee L Florent, Joy A. Becker, Mark D. PowellAbstract:This study examined the efficacy of Bithionol as a prophylactic or therapeutic oral treatment for Atlantic salmon (AS), Salmo salar, affected by amoebic gill disease (AGD). Furthermore, it explored the interaction of Bithionol oral therapy with the current standard treatment (a freshwater bath for at least 3 h). The efficacy of three medicated feeds was determined in the trial by feeding AGDaffected AS at 1% body weight (BW) day )1 either oil coated commercial feed (control) or prophylactic and therapeutic Bithionol at 25 mg kg )1 feed. Feeding commenced 2 weeks prior to exposure to Neoparamoeba spp. at 300 cells L )1 and continued for 49 days post-exposure (PE). Bithionol when fed as a 2-week prophylactic or therapeutic treatment at 25 mg kg )1 feed delayed the onset of AGD pathology and reduced the percentage of gill filaments with lesions. Administration of a 3-h freshwater bath at 28 days PE significantly reduced amoeba numbers to a similar level across all treatments; in contrast, gross gill score and percent lesioned filaments were reduced to different extents, the control having a significantly higher score than both Bithionol treatments. Following the freshwater bath, clinical signs of AGD increased at a similar level across all treatments, albeit controls were significantly higher than the Bithionol treatments immediately following freshwater treatment. This study demonstrated that Bithionol at 25 mg kg )1 feed, when fed as a 2-week prophylactic or a therapeutic treatment, delayed and reduced the intensity of AGD pathology and warrants further investigation as a treatment for AGD-affected AS.
-
Efficacy of Bithionol as an oral treatment for amoebic gill disease in Atlantic salmon Salmo salar (L.)
Aquaculture, 2007Co-Authors: Renee L Florent, Joy A. Becker, Mark D. PowellAbstract:This study examined the efficacy of Bithionol as an oral treatment for Atlantic salmon Salmo salar affected by amoebic gill disease (AGD). The current commercial management strategy of AGD is a costly 3 h freshwater bath. It is labour intensive and the number of baths needed appears to be increasing; hence, there is an effort to identify alternative treatments. Efficacy was examined by feeding AGD-affected Atlantic salmon twice daily to satiation with Bithionol, an antiprotozoal, at 25 mg kg −1 feed. Three seawater (35‰, 17 °C) re-circulation systems were used each consisting of three tanks containing 32 Atlantic salmon smolts with an average (±SEM) mass of 90.4 g (±5.2). Three feeds were examined in the trial including Bithionol, plain commercial control and oil coated commercial control. Feeding commenced 2 weeks prior to exposure to Neoparamoeba spp. at 300 cells L −1 and continued for 28 days post-exposure. Efficacy was determined by examining gross gill score and identifying percent lesioned gill filaments twice weekly for 4 weeks post-exposure. Bithionol when fed as a two-week prophylactic treatment at 25 mg kg −1 feed delayed the onset of AGD pathology and reduced the percent lesioned gill filaments by 53% and halved the gill score from 2 to 1 when compared with both the plain and oil controls during an experimental challenge. There were no palatability problems observed with mean feed intake of Bithionol over the trial duration with fish consuming higher levels of the Bithionol diet compared to both the oil and plain controls. This study demonstrated that Bithionol at 25 mg kg −1 feed, when fed as a two-week prophylactic treatment for Neoparamoeba spp. exposure, delayed and reduced the intensity of AGD pathology and warrants further investigation as an alternative to the current freshwater bath treatment for AGD-affected Atlantic salmon. © 2007 Elsevier B.V. All rights reserved.
-
Efficacy of Bithionol as an oral treatment for amoebic gill disease in Atlantic salmon Salmo salar (L.)
Aquaculture, 2007Co-Authors: Renee L Florent, Joy A. Becker, Mark D. PowellAbstract:This study examined the efficacy of Bithionol as an oral treatment for Atlantic salmon Salmo salar affected by amoebic gill disease (AGD). The current commercial management strategy of AGD is a costly 3 h freshwater bath. It is labour intensive and the number of baths needed appears to be increasing; hence, there is an effort to identify alternative treatments. Efficacy was examined by feeding AGD-affected Atlantic salmon twice daily to satiation with Bithionol, an antiprotozoal, at 25 mg kg−1 feed. Three seawater (35‰, 17 °C) re-circulation systems were used each consisting of three tanks containing 32 Atlantic salmon smolts with an average (±SEM) mass of 90.4 g (±5.2). Three feeds were examined in the trial including Bithionol, plain commercial control and oil coated commercial control. Feeding commenced 2 weeks prior to exposure to Neoparamoeba spp. at 300 cells L−1 and continued for 28 days post-exposure. Efficacy was determined by examining gross gill score and identifying percent lesioned gill filaments twice weekly for 4 weeks post-exposure. Bithionol when fed as a two-week prophylactic treatment at 25 mg kg−1 feed delayed the onset of AGD pathology and reduced the percent lesioned gill filaments by 53% and halved the gill score from 2 to 1 when compared with both the plain and oil controls during an experimental challenge. There were no palatability problems observed with mean feed intake of Bithionol over the trial duration with fish consuming higher levels of the Bithionol diet compared to both the oil and plain controls. This study demonstrated that Bithionol at 25 mg kg−1 feed, when fed as a two-week prophylactic treatment for Neoparamoeba spp. exposure, delayed and reduced the intensity of AGD pathology and warrants further investigation as an alternative to the current freshwater bath treatment for AGD-affected Atlantic salmon
-
Evaluation of Bithionol as a bath treatment for amoebic gill disease caused by Neoparamoeba spp.
Veterinary parasitology, 2006Co-Authors: Renee L Florent, Joy A. Becker, Mark D. PowellAbstract:This study examined the toxicity of Bithionol to Atlantic salmon Salmo salar and rainbow trout Oncorhynchus mykiss in fresh- and seawater and the efficacy of Bithionol as a 1h seawater bath treatment for amoebic gill disease (AGD). To examine toxicity, fish were bathed for 1, 3 and 6h in Bithionol, an anti-protozoal at 0, 1, 5, 10, 25 and 35mgL(-1) with toxicity determined by time to morbidity. Efficacy was examined by bathing AGD-affected Atlantic salmon and rainbow trout for 1h at Bithionol concentrations of 1-25mgL(-1). Efficacy was determined by examining gill amoeba counts and identifying percent lesioned gill filaments at 1 and 24h after bath exposure to Bithionol. For both species, Bithionol was determined to be toxic at 25 and 35mgL(-1) exhibiting median lethal times (LT50s) ranging from 21 to 84min. Morbidity occurred in the 5 and 10mgL(-1) treatments, however, due to sampling regime there were not enough fish available to calculate LT50s. Only Bithionol at 1mgL(-1) was considered non-toxic with no signs of morbidity. Bithionol was more toxic in seawater than freshwater and had no acute effects on gill Na+/K+ ATPase and succinic dehydrogenase, or plasma osmolality and chloride concentration. Bithionol at 1mgL(-1) reduced percent lesioned gill filaments in Atlantic salmon and rainbow trout by 33 and 27 per cent, respectively, compared to the seawater control. Similarly, numbers of amoeba were reduced by 33 and 43 per cent for Atlantic salmon and rainbow trout, respectively, when compared to the seawater control. Furthermore, Bithionol reduced percent lesioned gill filaments as much as did the current industry standard of freshwater. This study demonstrated that a 1h seawater bath containing 1mgL(-1) Bithionol could be an improvement to the current method of treatment for AGD-affected Atlantic salmon and rainbow trout.