M. Elgendy, Mohamed Abdelsalam, A. Kenawy, Nehal A. Younis
Motile aeromonads were identified in earthen-pond-farmed Oreochromis niloticus that suffered massive mortalities in Egypt during the summer of 2020. The fish showed hemorrhagic septicemic signs. Poor management practices and inadequate water quality measures were observed in the affected earthen ponds. Motile aeromonads (n = 31 isolates) were identified from 70 fish specimens. Based on their phenotypic and molecular characteristics, isolates were identified as: Aeromonas hydrophila (n = 12), A. veronii (n = 10), A. caviae (n = 5), and A. sobria (n = 4). Bacteriological examination of farm water samples also revealed aeromonads (n=9) and some fish-nonpathogenic bacteria. The aeromonad isolates recovered from fish exhibited lipase (52.5%) and protease (47.5%) activities and harboured some virulence genes: Ser (62.5%), Aer (55%), ela (37.5%), gcaT (32.5%), Hyl (25%), laf-A (22.5%), and Act (20%). They also harboured numerous antibiotic-resistance genes, including aadA (37.5%), tetC (32.5%), tetA (27.5%), sul 1 (20%), and blaTEM (10%). Virulence and antibiotic resistance genes were also noted in some of the Aeromonas spp. isolates obtained from farm water. Aeromonads were highly resistant to ampicillin, amoxicillin, and gentamicin but highly susceptible to ciprofloxacin and florfenicol antibiotics. Aeromonas spp pathogenicity was confirmed by the experimental infection of Oreochromis niloticus. Our results indicate a positive correlation between excessive tilapia mortalities, motile Aeromonas septicemia and adverse water quality parameters measured during the summer. This study provides data on the virulence, pathogenicity, and antibiotic resistance of motile aeromonads affecting fish and humans, which will be useful for developing efficient therapies.
{"title":"Phenotypic, genotypic and virulence traits analysis of aeromonads causing massive mortality in farmed Oreochromis niloticus","authors":"M. Elgendy, Mohamed Abdelsalam, A. Kenawy, Nehal A. Younis","doi":"10.48045/001c.118913","DOIUrl":"https://doi.org/10.48045/001c.118913","url":null,"abstract":"Motile aeromonads were identified in earthen-pond-farmed Oreochromis niloticus that suffered massive mortalities in Egypt during the summer of 2020. The fish showed hemorrhagic septicemic signs. Poor management practices and inadequate water quality measures were observed in the affected earthen ponds. Motile aeromonads (n = 31 isolates) were identified from 70 fish specimens. Based on their phenotypic and molecular characteristics, isolates were identified as: Aeromonas hydrophila (n = 12), A. veronii (n = 10), A. caviae (n = 5), and A. sobria (n = 4). Bacteriological examination of farm water samples also revealed aeromonads (n=9) and some fish-nonpathogenic bacteria. The aeromonad isolates recovered from fish exhibited lipase (52.5%) and protease (47.5%) activities and harboured some virulence genes: Ser (62.5%), Aer (55%), ela (37.5%), gcaT (32.5%), Hyl (25%), laf-A (22.5%), and Act (20%). They also harboured numerous antibiotic-resistance genes, including aadA (37.5%), tetC (32.5%), tetA (27.5%), sul 1 (20%), and blaTEM (10%). Virulence and antibiotic resistance genes were also noted in some of the Aeromonas spp. isolates obtained from farm water. Aeromonads were highly resistant to ampicillin, amoxicillin, and gentamicin but highly susceptible to ciprofloxacin and florfenicol antibiotics. Aeromonas spp pathogenicity was confirmed by the experimental infection of Oreochromis niloticus. Our results indicate a positive correlation between excessive tilapia mortalities, motile Aeromonas septicemia and adverse water quality parameters measured during the summer. This study provides data on the virulence, pathogenicity, and antibiotic resistance of motile aeromonads affecting fish and humans, which will be useful for developing efficient therapies.","PeriodicalId":55306,"journal":{"name":"Bulletin of the European Association of Fish Pathologists","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141368831","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
As alternatives to antibiotics and growth promoters, herbs and medicinal plants can contribute to new strategies for aquatic health management, and have great potential for more sustainable aquaculture. Four plants, Pelargonium roseum, Schinus terenbinthifolius, Murraya koenigii and Aphloia theiformis, widely distributed in tropical countries were studied to assess their efficacy in the prevention and reduction of mortality caused by experimental infection with Aeromonas hydrophila on Nile tilapia, Oreochromis niloticus. Powdered plants were incorporated into fish feed, and fish were fed with an enriched diet for 40 days before a challenge with the pathogen. No negative impact on the condition factor, weight gain or specific growth rate was observed in fish fed with the plant supplements, and the best growth was observed in fish fed with P. roseum. Mortality was significantly reduced in fish treated with A. theiformis compared to other fish from plant species and control, with a relative survival rate (RPS) of up to 30%.
作为抗生素和生长促进剂的替代品，草本植物和药用植物可为水产健康管理的新策略做出贡献，并对更可持续的水产养殖具有巨大潜力。研究人员对广泛分布于热带国家的四种植物，即天竺葵、蓖麻子、鹅掌楸和Aphloia theiformis进行了研究，以评估它们在尼罗罗非鱼（Oreochromis niloticus）试验性感染嗜水气单胞菌（Aeromonas hydrophila）后预防和降低死亡率的功效。将植物粉末添加到鱼饲料中，在病原体侵袭之前用富含植物粉末的饲料喂养鱼 40 天。用植物补充剂喂养的鱼对体况系数、增重或特定生长率没有负面影响，用玫瑰草喂养的鱼生长最好。与其他植物种类的鱼类和对照组相比，使用 A. theiformis 的鱼类死亡率明显降低，相对存活率（RPS）高达 30%。
{"title":"Four powdered plants for prevention of Aeromonas hydrophila disease in Nile tilapia (Oreochromis niloticus)","authors":"D. Caruso, L.L. Estevez, C. Marodon, S. Sarter","doi":"10.48045/001c.90008","DOIUrl":"https://doi.org/10.48045/001c.90008","url":null,"abstract":"As alternatives to antibiotics and growth promoters, herbs and medicinal plants can contribute to new strategies for aquatic health management, and have great potential for more sustainable aquaculture. Four plants, Pelargonium roseum, Schinus terenbinthifolius, Murraya koenigii and Aphloia theiformis, widely distributed in tropical countries were studied to assess their efficacy in the prevention and reduction of mortality caused by experimental infection with Aeromonas hydrophila on Nile tilapia, Oreochromis niloticus. Powdered plants were incorporated into fish feed, and fish were fed with an enriched diet for 40 days before a challenge with the pathogen. No negative impact on the condition factor, weight gain or specific growth rate was observed in fish fed with the plant supplements, and the best growth was observed in fish fed with P. roseum. Mortality was significantly reduced in fish treated with A. theiformis compared to other fish from plant species and control, with a relative survival rate (RPS) of up to 30%.","PeriodicalId":55306,"journal":{"name":"Bulletin of the European Association of Fish Pathologists","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139790926","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
As alternatives to antibiotics and growth promoters, herbs and medicinal plants can contribute to new strategies for aquatic health management, and have great potential for more sustainable aquaculture. Four plants, Pelargonium roseum, Schinus terenbinthifolius, Murraya koenigii and Aphloia theiformis, widely distributed in tropical countries were studied to assess their efficacy in the prevention and reduction of mortality caused by experimental infection with Aeromonas hydrophila on Nile tilapia, Oreochromis niloticus. Powdered plants were incorporated into fish feed, and fish were fed with an enriched diet for 40 days before a challenge with the pathogen. No negative impact on the condition factor, weight gain or specific growth rate was observed in fish fed with the plant supplements, and the best growth was observed in fish fed with P. roseum. Mortality was significantly reduced in fish treated with A. theiformis compared to other fish from plant species and control, with a relative survival rate (RPS) of up to 30%.
作为抗生素和生长促进剂的替代品，草本植物和药用植物可为水产健康管理的新策略做出贡献，并对更可持续的水产养殖具有巨大潜力。研究人员对广泛分布于热带国家的四种植物，即天竺葵、蓖麻子、鹅掌楸和Aphloia theiformis进行了研究，以评估它们在尼罗罗非鱼（Oreochromis niloticus）试验性感染嗜水气单胞菌（Aeromonas hydrophila）后预防和降低死亡率的功效。将植物粉末添加到鱼饲料中，在病原体侵袭之前用富含植物粉末的饲料喂养鱼 40 天。用植物补充剂喂养的鱼对体况系数、增重或特定生长率没有负面影响，用玫瑰草喂养的鱼生长最好。与其他植物种类的鱼类和对照组相比，使用 A. theiformis 的鱼类死亡率明显降低，相对存活率（RPS）高达 30%。
{"title":"Four powdered plants for prevention of Aeromonas hydrophila disease in Nile tilapia (Oreochromis niloticus)","authors":"D. Caruso, L.L. Estevez, C. Marodon, S. Sarter","doi":"10.48045/001c.90008","DOIUrl":"https://doi.org/10.48045/001c.90008","url":null,"abstract":"As alternatives to antibiotics and growth promoters, herbs and medicinal plants can contribute to new strategies for aquatic health management, and have great potential for more sustainable aquaculture. Four plants, Pelargonium roseum, Schinus terenbinthifolius, Murraya koenigii and Aphloia theiformis, widely distributed in tropical countries were studied to assess their efficacy in the prevention and reduction of mortality caused by experimental infection with Aeromonas hydrophila on Nile tilapia, Oreochromis niloticus. Powdered plants were incorporated into fish feed, and fish were fed with an enriched diet for 40 days before a challenge with the pathogen. No negative impact on the condition factor, weight gain or specific growth rate was observed in fish fed with the plant supplements, and the best growth was observed in fish fed with P. roseum. Mortality was significantly reduced in fish treated with A. theiformis compared to other fish from plant species and control, with a relative survival rate (RPS) of up to 30%.","PeriodicalId":55306,"journal":{"name":"Bulletin of the European Association of Fish Pathologists","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139850804","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Red Mark Syndrome (RMS) is a skin disease affecting predominantly rainbow trout and is likely caused by a Midichloria-like organism. This condition primarily affects commercially-sized fish and can cause severe chronic dermatitis, panniculitis, and myositis, ultimately resulting in significant economic losses. RMS has been reported in at least three continents, but its presence has only been confirmed in Chile within South America. Nevertheless, it continues to pose a significant threat to the aquaculture of rainbow trout. In this context, we present the first documented outbreak of RMS in Peruvian Salmonid Aquaculture.
{"title":"Red mark syndrome (RMS) in farmed rainbow trout (<i>Oncorhynchus mykiss</i>): first report of outbreak in Peruvian Salmonid Aquaculture.","authors":"Y. Ortega, N. Sandoval, M. Orioles","doi":"10.48045/001c.88466","DOIUrl":"https://doi.org/10.48045/001c.88466","url":null,"abstract":"Red Mark Syndrome (RMS) is a skin disease affecting predominantly rainbow trout and is likely caused by a Midichloria-like organism. This condition primarily affects commercially-sized fish and can cause severe chronic dermatitis, panniculitis, and myositis, ultimately resulting in significant economic losses. RMS has been reported in at least three continents, but its presence has only been confirmed in Chile within South America. Nevertheless, it continues to pose a significant threat to the aquaculture of rainbow trout. In this context, we present the first documented outbreak of RMS in Peruvian Salmonid Aquaculture.","PeriodicalId":55306,"journal":{"name":"Bulletin of the European Association of Fish Pathologists","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135869051","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
N. N. Fuandila, A. Lusiastuti, M. Yuhana, A. Santika, Anne-Sophie Gosselin-Grenet, E. Cherif, J. Avarre
Cyprinid herpesvirus-3 (CyHV-3) is the etiological agent of koi herpesvirus disease (KHVD) in common and koi carp farming. This highly contagious pathogen has a 295-kb genome that harbours 156 open reading frames. Recent in vitro experimental evolution studies highlighted strong dynamics of genomic structural variations (SVs), in particular in the region of ORF150, an ORF potentially involved in virus multiplication and host inflammatory response. Among these SVs, a 1363-bp deletion could be associated with a loss of virulence. The present study aimed at investigating the genomic variations in the ORF150 region, and especially the deletion, in viruses isolated from carp populations of Indonesia. A screening of 236 fish from 43 different farms revealed a high prevalence of CyHV-3 (nearly 70%), both in symptomatic and asymptomatic common carp. However, in contrast with the results obtained in vitro, long read sequencing of the ORF150 region revealed a low level of genetic variations and the absence of the 1363-pb deletion. The complex interactions between the virus, the environment and the host, particularly the immune system, probably play an important role in this reduced variability.
{"title":"Prevalence of Cyprinid herpesvirus 3 and ORF150 genomic variations in carp populations of Indonesia","authors":"N. N. Fuandila, A. Lusiastuti, M. Yuhana, A. Santika, Anne-Sophie Gosselin-Grenet, E. Cherif, J. Avarre","doi":"10.48045/001c.84009","DOIUrl":"https://doi.org/10.48045/001c.84009","url":null,"abstract":"Cyprinid herpesvirus-3 (CyHV-3) is the etiological agent of koi herpesvirus disease (KHVD) in common and koi carp farming. This highly contagious pathogen has a 295-kb genome that harbours 156 open reading frames. Recent in vitro experimental evolution studies highlighted strong dynamics of genomic structural variations (SVs), in particular in the region of ORF150, an ORF potentially involved in virus multiplication and host inflammatory response. Among these SVs, a 1363-bp deletion could be associated with a loss of virulence. The present study aimed at investigating the genomic variations in the ORF150 region, and especially the deletion, in viruses isolated from carp populations of Indonesia. A screening of 236 fish from 43 different farms revealed a high prevalence of CyHV-3 (nearly 70%), both in symptomatic and asymptomatic common carp. However, in contrast with the results obtained in vitro, long read sequencing of the ORF150 region revealed a low level of genetic variations and the absence of the 1363-pb deletion. The complex interactions between the virus, the environment and the host, particularly the immune system, probably play an important role in this reduced variability.","PeriodicalId":55306,"journal":{"name":"Bulletin of the European Association of Fish Pathologists","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45310415","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Sandra C. Soares, J. Black, D. Bradley, M. Fordyce, R. McIntosh
Atlantic mackerel (Scomber scombrus) is a very important and valuable pelagic fish in Scotland. This species is known to be one of the hosts for Kudoa thyrsites, the myxosporean agent of post-mortem myoliquefaction, known as ‘soft tissue’. To date, there have been no official reports of the parasite in Scottish waters, however, the soft tissue condition is known to be found in Scottish landed mackerel. Its impact on this fishery is therefore unknown. The present study aims to report the presence of K. thyrsites-induced post-mortem myoliquefaction in mackerel caught from Scottish waters. Four commercial-sized mackerel displaying features of soft tissue were sampled. The histopathological examination revealed areas of muscular fibre necrosis and the presence of several multivalvulid myxospores in the interstitial space between the muscular fibres and among the liquefied necrotic areas. The presence of the K. thrysites was confirmed by polymerase chain reaction (PCR) in three of the four mackerel muscle tested and showed 100% identity with K. thyrsites isolate MH899081.1.
{"title":"Identification of Kudoa thyrsites in Atlantic mackerel (Scomber scombrus) displaying post-mortem myoliquefaction: a case study in Scotland","authors":"Sandra C. Soares, J. Black, D. Bradley, M. Fordyce, R. McIntosh","doi":"10.48045/001c.84172","DOIUrl":"https://doi.org/10.48045/001c.84172","url":null,"abstract":"Atlantic mackerel (Scomber scombrus) is a very important and valuable pelagic fish in Scotland. This species is known to be one of the hosts for Kudoa thyrsites, the myxosporean agent of post-mortem myoliquefaction, known as ‘soft tissue’. To date, there have been no official reports of the parasite in Scottish waters, however, the soft tissue condition is known to be found in Scottish landed mackerel. Its impact on this fishery is therefore unknown. The present study aims to report the presence of K. thyrsites-induced post-mortem myoliquefaction in mackerel caught from Scottish waters. Four commercial-sized mackerel displaying features of soft tissue were sampled. The histopathological examination revealed areas of muscular fibre necrosis and the presence of several multivalvulid myxospores in the interstitial space between the muscular fibres and among the liquefied necrotic areas. The presence of the K. thrysites was confirmed by polymerase chain reaction (PCR) in three of the four mackerel muscle tested and showed 100% identity with K. thyrsites isolate MH899081.1.","PeriodicalId":55306,"journal":{"name":"Bulletin of the European Association of Fish Pathologists","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-07-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48381478","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Kaplan, K. Pekmez, A. Çağırgan, B. K. Tekelioglu, U. Oğuz, B. Kafa, F. Arslan, G. Kalaycı
Viral nervous necrosis is a viral disease caused by betanodavirus causing deaths and epidemics in wild or farmed sea fish, especially in juveniles. Betanodavirus has been detected in farmed European seabass and gilthead seabream in Turkey. However, there are no studies on the presence of betanodavirus in wildlife along the Turkish Mediterranean coast. This study aimed to investigate the presence of betanodavirus in wild fish along the Turkish coast of the Mediterranean and to characterize isolates using molecular tools. Hence, 400 fish belonging to 27 different wild species were caught and tested using real-time RT‒PCR. The betanodavirus genome was detected in red mullets (25/50) and garfish (2/4) and identified as RGNNV and RGNNV/SJNNV genotype, respectively according to partial genome sequencing of the RNA1 and RNA2 segments. Phylogenetic analysis showed that isolated viruses were similar to isolates collected from other parts of the Mediterranean Sea and China, India, and Japan. The results of the studies show that different genotypes are circulating in the studied region in different species. These findings indicates that more research on wildlife, both around the farm and in other regions, are needed to prevent spreading of the virus to aquaculture facilities.
{"title":"Survey on Betanodavirus in Wild Fish Species in the Turkish Coastlines of the Mediterranean Sea and Molecular Characterization: detecting different genotypes from different fish in different locations","authors":"M. Kaplan, K. Pekmez, A. Çağırgan, B. K. Tekelioglu, U. Oğuz, B. Kafa, F. Arslan, G. Kalaycı","doi":"10.48045/001c.74914","DOIUrl":"https://doi.org/10.48045/001c.74914","url":null,"abstract":"Viral nervous necrosis is a viral disease caused by betanodavirus causing deaths and epidemics in wild or farmed sea fish, especially in juveniles. Betanodavirus has been detected in farmed European seabass and gilthead seabream in Turkey. However, there are no studies on the presence of betanodavirus in wildlife along the Turkish Mediterranean coast. This study aimed to investigate the presence of betanodavirus in wild fish along the Turkish coast of the Mediterranean and to characterize isolates using molecular tools. Hence, 400 fish belonging to 27 different wild species were caught and tested using real-time RT‒PCR. The betanodavirus genome was detected in red mullets (25/50) and garfish (2/4) and identified as RGNNV and RGNNV/SJNNV genotype, respectively according to partial genome sequencing of the RNA1 and RNA2 segments. Phylogenetic analysis showed that isolated viruses were similar to isolates collected from other parts of the Mediterranean Sea and China, India, and Japan. The results of the studies show that different genotypes are circulating in the studied region in different species. These findings indicates that more research on wildlife, both around the farm and in other regions, are needed to prevent spreading of the virus to aquaculture facilities.","PeriodicalId":55306,"journal":{"name":"Bulletin of the European Association of Fish Pathologists","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47668808","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Shrimp farming has been devastated by several diseases. Disease outbreaks can be prevented by optimising environmental conditions or by eliminating risks factors including carrier organisms. These can be achieved through proper pond preparation. One important step in pond preparation is the application of hydrated lime. This paper describes the effect of hydrated lime application to condition pond soil to pH 11 on the pond ecosystem, more specifically on soil pH and biota. The experiment was done using three 600 m2 brackish water ponds. After hydrated lime application, the wet soil pH on the 1st-8th day was significantly higher (P<0.05) compared to the pH before liming to pH 11, and flushing after flooding for 24 h. Soil pH of 11 was observed 24-48h after lime application. Moreover, unwanted species like crabs and fish were found dead. Liming to pH 11 negatively affects the counts of green vibrio colonies thereby decreasing the percentage of green vibrios (PGV). In another experiment, three 750m2 earthen ponds were used. The pond soils were previously positive for the Whitespot Syndrome Virus (WSSV), hydrated lime were applied to bring the pond soil pH to 11. After lime application, WSSV was not detected in the pond soils. Results showed that increasing the soil pH to ≥11 positively affects the pond ecosystem. Liming encourages the proliferation of yellow vibrios and the eradication of carrier species (i.e. crabs) as well as predators (i.e. fish) in the ponds. Furthermore, liming to pH 11 may also eradicate White spot virus from the pond sediment. To implement a 1-unit increase in wet pH, hydrated lime should be applied at 2T/ha.
{"title":"Lime application to condition soil to pH 11 controls growth of harmful vibrios and WSSV","authors":"E. A. Tendencia, E. Coniza","doi":"10.48045/001c.74917","DOIUrl":"https://doi.org/10.48045/001c.74917","url":null,"abstract":"Shrimp farming has been devastated by several diseases. Disease outbreaks can be prevented by optimising environmental conditions or by eliminating risks factors including carrier organisms. These can be achieved through proper pond preparation. One important step in pond preparation is the application of hydrated lime. This paper describes the effect of hydrated lime application to condition pond soil to pH 11 on the pond ecosystem, more specifically on soil pH and biota. The experiment was done using three 600 m2 brackish water ponds. After hydrated lime application, the wet soil pH on the 1st-8th day was significantly higher (P<0.05) compared to the pH before liming to pH 11, and flushing after flooding for 24 h. Soil pH of 11 was observed 24-48h after lime application. Moreover, unwanted species like crabs and fish were found dead. Liming to pH 11 negatively affects the counts of green vibrio colonies thereby decreasing the percentage of green vibrios (PGV). In another experiment, three 750m2 earthen ponds were used. The pond soils were previously positive for the Whitespot Syndrome Virus (WSSV), hydrated lime were applied to bring the pond soil pH to 11. After lime application, WSSV was not detected in the pond soils. Results showed that increasing the soil pH to ≥11 positively affects the pond ecosystem. Liming encourages the proliferation of yellow vibrios and the eradication of carrier species (i.e. crabs) as well as predators (i.e. fish) in the ponds. Furthermore, liming to pH 11 may also eradicate White spot virus from the pond sediment. To implement a 1-unit increase in wet pH, hydrated lime should be applied at 2T/ha.","PeriodicalId":55306,"journal":{"name":"Bulletin of the European Association of Fish Pathologists","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42236757","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Sea Star Wasting Disease (SSWD) affects several wild and captive starfish species. It is generally thought to be infectious, with environmental conditions favouring its progression. Captive Asterias rubens with varying degrees of epidermal ulceration, limb autotomy and eversion of viscera were examined. Antibiotic treatments by injections and baths did not reduce mortality.
{"title":"Sea Star Wasting Disease in captive common sea stars (Asterias rubens): Examinations, therapy attempts and course of disease","authors":"K. Grassl, J. Bauer","doi":"10.48045/001c.73028","DOIUrl":"https://doi.org/10.48045/001c.73028","url":null,"abstract":"Sea Star Wasting Disease (SSWD) affects several wild and captive starfish species. It is generally thought to be infectious, with environmental conditions favouring its progression. Captive Asterias rubens with varying degrees of epidermal ulceration, limb autotomy and eversion of viscera were examined. Antibiotic treatments by injections and baths did not reduce mortality.","PeriodicalId":55306,"journal":{"name":"Bulletin of the European Association of Fish Pathologists","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48591701","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Orioles, J. G. Schmidt, P. Tome, N. Vendramin, M. Galeotti
Red mark syndrome (RMS) is a widespread skin disease of rainbow trout (Oncorhynchus mykiss). Its aetiological agent is believed to be a Midichloria-like organism, an intracellular bacteria of the order Rickettsiales. RMS has been reported on several occasions, however, a comprehensive analysis of the epidemiology of this disease and its actual economic impact on the trout aquaculture industry is missing. Through a questionnaire-based survey, we estimated the prevalence of RMS and the implications of this infection on trout farms in Italy in 2020-2021. One hundred and nine farms, representing 64% (around 22,000 tons) of the total national production, were surveyed. In short, the results show that RMS in Italian farms is consistently and persistently present on Italian territory, affecting about 30% of farms. RMS is observed to have similar features to those generally described in the literature. Clinical disease is observed more often in springtime; size-wise, the most commonly affected groups are fish close to market size and fish weighing less than 100g (22% of cases). Most interestingly, the recurrence of clinical signs in the same batch of fish was observed in 64% of cases. Despite its diffusion, the disease is not perceived as a major concern in the national trout sector, mainly due to its intermittent nature, low mortality and spontaneous resolution. The main costs associated with RMS were related to antibiotic treatment and commercial downgrading; however, it was impossible to estimate the impact of these on production costs.
{"title":"A questionnaire-based survey on the presence of red mark syndrome in Italian rainbow trout (Oncorhynchus mykiss) farms","authors":"M. Orioles, J. G. Schmidt, P. Tome, N. Vendramin, M. Galeotti","doi":"10.48045/001c.71292","DOIUrl":"https://doi.org/10.48045/001c.71292","url":null,"abstract":"Red mark syndrome (RMS) is a widespread skin disease of rainbow trout (Oncorhynchus mykiss). Its aetiological agent is believed to be a Midichloria-like organism, an intracellular bacteria of the order Rickettsiales. RMS has been reported on several occasions, however, a comprehensive analysis of the epidemiology of this disease and its actual economic impact on the trout aquaculture industry is missing. Through a questionnaire-based survey, we estimated the prevalence of RMS and the implications of this infection on trout farms in Italy in 2020-2021. One hundred and nine farms, representing 64% (around 22,000 tons) of the total national production, were surveyed. In short, the results show that RMS in Italian farms is consistently and persistently present on Italian territory, affecting about 30% of farms. RMS is observed to have similar features to those generally described in the literature. Clinical disease is observed more often in springtime; size-wise, the most commonly affected groups are fish close to market size and fish weighing less than 100g (22% of cases). Most interestingly, the recurrence of clinical signs in the same batch of fish was observed in 64% of cases. Despite its diffusion, the disease is not perceived as a major concern in the national trout sector, mainly due to its intermittent nature, low mortality and spontaneous resolution. The main costs associated with RMS were related to antibiotic treatment and commercial downgrading; however, it was impossible to estimate the impact of these on production costs.","PeriodicalId":55306,"journal":{"name":"Bulletin of the European Association of Fish Pathologists","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49640658","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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