To identify the cause of mass mortality of adult Macrobrachium rosenbergii in a farm in Gaoyou City,Jiangsu Province,China,a dominant strain named DKQ-1 was isolated from the hepatopancreas of dying M.rosenbergii and ...To identify the cause of mass mortality of adult Macrobrachium rosenbergii in a farm in Gaoyou City,Jiangsu Province,China,a dominant strain named DKQ-1 was isolated from the hepatopancreas of dying M.rosenbergii and identified as Aeromonas dhakensis by purification culture,biochemical characterization,and 16S rRNA and gyrB gene sequence analysis.The results of the challenge test revealed that the strain was highly pathogenic and the 50%lethal dose(LD_(50))in 72 h to M.rosenbergii was 1.54×10^(5)CFU/mL.The amplification results of virulence genes show that strain DKQ-1 carried 9 virulence genes,including ascV,aexT,aer,act,lip,ompAI,gcaT,acg,and exu,supporting the strong virulence of strain DKQ-1 to M.rosenbergii.Histopathological observation of the hepatopancreas,gills,and intestines indicated that DKQ-1 injection into M.rosenbergii could cause serious tissue damage,which further supported the strong virulence of this strain.In addition,a drug susceptibility test revealed that strain DKQ-1 was sensitive to 16 kinds of antibiotics,resistant to 9 kinds of antibiotics,and had intermediate resistance to spectinomycin and kanamycin.This study is the first report of A.dhakensis isolated from M.rosenbergii and provided a reference for the pathogen identification of bacterial diseases in M.rosenbergii,and for the prevention and treatment caused by A.dhakensis.展开更多
The giant freshwater prawn Macrobrachium rosenbergii distributed from tropical to subtropical regions,is a warm-water species,and its survival temperature is 14-35°C,which greatly limits its culture cycle and cul...The giant freshwater prawn Macrobrachium rosenbergii distributed from tropical to subtropical regions,is a warm-water species,and its survival temperature is 14-35°C,which greatly limits its culture cycle and culture area in China.Therefore,it is urgent to cultivate a new high quality,high yield variety with improved cold-resistance,but the genetic parameters for cold-resistance traits are unknown in M.rosenbergii.In this study,the cold-resistance of adult M.rosenbergii populations was tested using the indoor artificial cooling method.Individuals were selected from 139 families of Shufeng G3 generation and cultured for 200 days.A linear mixed model was constructed by ASReml-R to evaluate the genetic parameters of the cold-resistance trait(cooling degree hours,CDH)and growth traits(body weight,BW,and body length,BL)based on the restricted maximum likelihood(REML)method.The results show that the heritability of CDH was low(0.12±0.05),while the growth traits(BW and BL)had low to moderate heritability,with 0.20±0.06 for BW and 0.06±0.04 for BL.The phenotypic and genetic correlation between BW and BL was significantly positive,but significantly negative phenotypic and genetic correlations were detected between CDH and BW and between CDH and BL.Furthermore,the analysis of the differences between cold-resistance and phenotypic traits showed that the female reproductive status,exoskeleton hardness and claw number of adult prawns had a great influence on the cold-resistance of M.rosenbergii(P<0.05),indicating that adults with claws and hard exoskeletons are preferred as parents in subsequent breeding selection.The present results can be attributed to the selection and breeding of a new cold-resistant variety of M.rosenbergii.展开更多
A nucleic acid sequence-based amplification(NASBA)assay was established for the detection of Macrobrachium rosenbergii Nodavirus(MrNV).The specific primers were designed according to the high conserved region of RNA2 ...A nucleic acid sequence-based amplification(NASBA)assay was established for the detection of Macrobrachium rosenbergii Nodavirus(MrNV).The specific primers were designed according to the high conserved region of RNA2 sequence of MrNV.The 224 bp specific amplification product was obtained in positive sample determined with 3%agarose gel electrophoresis,while no product was generated from shrimp infected with other viruses including DNA viruses(IHHNV,WSSV)and RNA viruses(TSV,IMNV,YHV).The detecting limit of the assay was 8pg nucleic acid,which is more sensitive than that of PCR method.展开更多
传染性皮下和造血器官坏死病毒(infectious hypodermal and hematopoietic necrosis virus,IHHNV)是对虾养殖的重要病原之一,可感染多种虾种。罗氏沼虾(Macrobrachium rosenbergii)是中国养殖的重要沼虾品种之一。根据国际兽疫局(Office...传染性皮下和造血器官坏死病毒(infectious hypodermal and hematopoietic necrosis virus,IHHNV)是对虾养殖的重要病原之一,可感染多种虾种。罗氏沼虾(Macrobrachium rosenbergii)是中国养殖的重要沼虾品种之一。根据国际兽疫局(Office International des Epizooties,OIE)推荐的IHHNV检测方法,在中国大陆地区首次开展IHHNV在罗氏沼虾中的感染和流行情况调查。结果显示,在研究区的罗氏沼虾养殖区,IHHNV广泛流行,阳性率高达90%;但所有成年罗氏沼虾均未表现出明显的病症,仅表现为病毒的携带。通过基因序列分析显示,检测到的华南地区毒株属于Ⅰ型感染株,与菲律宾株进化关系较为接近;华东地区毒株属于Ⅱ型感染株,与东南亚株进化关系较近。本研究为IHHNV在罗氏沼虾内的感染、流行和防控提供了详细参考。展开更多
In this article, antibiogram and heavy metal resistance profile of bacteria isolated from giant freshwater prawn (Macrobrachium rosenbergii) hatchery in Malaysia are described. Although giant freshwater prawn was intr...In this article, antibiogram and heavy metal resistance profile of bacteria isolated from giant freshwater prawn (Macrobrachium rosenbergii) hatchery in Malaysia are described. Although giant freshwater prawn was introduced into Malaysia since the 1980s, there was no database information on antibiogram and heavy metal resistance profile of bacteria from giant freshwater prawn (M. rosenbergii) hatchery in Malaysia. Therefore, this study was carried out to determine the effectiveness of antibiotic and heavy metal resistance profile to control bacterial diseases in M. rosenbergii hatchery. The results can provide valuable information for local M. rosenbergii post-larval producer. Antibiotic sensitivity test was carried out by disk-diffusion method against 15 types of antibiotics as follows: oxolinic acid (2 μg), ampicillin (10 μg), erythromycin (15 μg), furazolidone (15 μg), lincomycin (15 μg), amoxicillin (25 μg), colistin sulphate (25 μg), doxycycline (30 μg), florfenicol (30 μg), flumequine (30 μg), nalidixic acid (30 μg), tetracycline (30 μg), oleandomycin (15 μg), fosfomycin (50 μg), and spiramycin (100 μg), whereas heavy metal resistance profile of the present bacterial isolates was determined by 2-fold agar dilution technique. In this study, 5 types of bacteria were successfully isolated; they were Aeromonas spp. (n = 77), Escherichia coli (n = 73), Edwardsiella spp. (n = 62), Salmonella spp. (n = 75), and Vibrio spp. (n = 43). The result showed that furazolidone was the most effective antibiotic to control the bacteria isolated in this study, approximately 89.7% of the bacterial isolates were sensitive to this antibiotic. Multiple antibiotic resistance (MAR) index indicated that the hatchery water source and M. rosenbergii post-larval and sediment tanks were at high-risk exposure to the tested antibiotic. Furthermore, all the tested heavy metals (Cd2+, Cr6+, Hg2+, and Cu2+) failed to inhibit the growth of the bacterial isolates. Therefore, it indicated that the water source of the hatchery is contaminated with both antibiotic residues and heavy metal.展开更多
There are reports on the use of chemicals like sodium tri polyphosphate (STPP) and foreign materials like pearl tapioca (locally called ‘sagu’), jelly (litchi) to adulterate freshwater prawn (Macrobrachium rosenberg...There are reports on the use of chemicals like sodium tri polyphosphate (STPP) and foreign materials like pearl tapioca (locally called ‘sagu’), jelly (litchi) to adulterate freshwater prawn (Macrobrachium rosenbergii) prior to freeze processing to increase their weight. Studies were, therefore, undertaken to determine the changes in product quality on the use of different concentrations of STPP, sagu and litchi under ice storage condition. Percent weight gain of prawn was 5.46, 18.87 and 23.50 when dipped in 2%, 4% and 6% STPP solution, respectively. In all cases maximum water uptake by prawn muscle was during the first 6 h with fastest weight gain with STPP solutions containing tap water compared to those of ice and tap water. Organoleptic quality of the STPP treated samples became brown and spongy after 8 h of dipping treatment under iced condition. Quality assessment studies conducted after injecting sagu and litchi in prawn muscle showed little or no difference with those of control samples during the first 6 h, which turned whitish and swollen with severe drip loss after 24 h of ice stored condition, indicating characteristics for easy identification of the injected shrimps by organoleptic method.展开更多
Objective:To characterize the major allergens of Macrobrachium rosenbergii.(giant freshwater prawn).Methods:Raw and cooked extracts of the giant freshwater prawn were prepared.The IgE reactivity pattern was identified...Objective:To characterize the major allergens of Macrobrachium rosenbergii.(giant freshwater prawn).Methods:Raw and cooked extracts of the giant freshwater prawn were prepared.The IgE reactivity pattern was identified by sodium dodecyl sulfate polyaerylamide gel electrophoresis(SDS-PAGE)and immunoblotting technique with the sera of 20 skin prick test(SPT)positive patients.The major allergen identified was then characterized using the proteomics approach involving a combination of two-dimensional(2-DE)electrophoresis,mass spectrometry and bioinformatics tools.Results:SDS-PAGE of the raw extract showed 23 protein bands(15-250 kDa)but those ranging from 40 to 100 kDa were not found in the cooked extract.From immunoblotting experiments,raw and cooked extracts demonstrated 11 and 5 IgE-binding proteins,respectively,with a molecular mass ranging from 15 to 155 kDa.A heat-resistant 36 kDa protein was identified as the major allergen of both extracts.In addition,a 42 kDa heat-sensitive protein was shown to be a major allergen of the raw extract.The 2-DE gel fractionated the prawn proteins to more than 50 different protein spots.Of these,10 spots showed specific:IgE reactivity with patients'sera.Matrix assisted laser desorption/ionization-lime of flight(MALDI-TOF)analysis led to identification of 2 important allergens,tropomyosin and arginine kinase.Conclusions:It can be concluded that the availability of such allergens would help in component-based diagnosis and therapy of prawn allergies.展开更多
基金Supported by the Earmarked Fund for the China Agriculture Research System(No.CARS-48)the Key Scientific and Technological Grant of Zhejiang for Breeding New Agricultural Varieties(No.2021 C 02069-4-3)the Major Research&Development Program(modern agriculture)of Jiangsu Province(No.BE 2019352)。
文摘To identify the cause of mass mortality of adult Macrobrachium rosenbergii in a farm in Gaoyou City,Jiangsu Province,China,a dominant strain named DKQ-1 was isolated from the hepatopancreas of dying M.rosenbergii and identified as Aeromonas dhakensis by purification culture,biochemical characterization,and 16S rRNA and gyrB gene sequence analysis.The results of the challenge test revealed that the strain was highly pathogenic and the 50%lethal dose(LD_(50))in 72 h to M.rosenbergii was 1.54×10^(5)CFU/mL.The amplification results of virulence genes show that strain DKQ-1 carried 9 virulence genes,including ascV,aexT,aer,act,lip,ompAI,gcaT,acg,and exu,supporting the strong virulence of strain DKQ-1 to M.rosenbergii.Histopathological observation of the hepatopancreas,gills,and intestines indicated that DKQ-1 injection into M.rosenbergii could cause serious tissue damage,which further supported the strong virulence of this strain.In addition,a drug susceptibility test revealed that strain DKQ-1 was sensitive to 16 kinds of antibiotics,resistant to 9 kinds of antibiotics,and had intermediate resistance to spectinomycin and kanamycin.This study is the first report of A.dhakensis isolated from M.rosenbergii and provided a reference for the pathogen identification of bacterial diseases in M.rosenbergii,and for the prevention and treatment caused by A.dhakensis.
基金Supported by the Key Scientific and Technological Grant of Zhejiang for Breeding New Agricultural(Aquaculture)Varieties(No.2021C02069-4-3)the Major Research&Development Program(Modern Agriculture)of Jiangsu Province(No.BE2019352)+1 种基金the Earmarked Fund for the China Agriculture Research System(No.CARS-48)the Innovation Project of Postgraduate Scientific Research in Huzhou University in 2022(No.2022KYCX63)。
文摘The giant freshwater prawn Macrobrachium rosenbergii distributed from tropical to subtropical regions,is a warm-water species,and its survival temperature is 14-35°C,which greatly limits its culture cycle and culture area in China.Therefore,it is urgent to cultivate a new high quality,high yield variety with improved cold-resistance,but the genetic parameters for cold-resistance traits are unknown in M.rosenbergii.In this study,the cold-resistance of adult M.rosenbergii populations was tested using the indoor artificial cooling method.Individuals were selected from 139 families of Shufeng G3 generation and cultured for 200 days.A linear mixed model was constructed by ASReml-R to evaluate the genetic parameters of the cold-resistance trait(cooling degree hours,CDH)and growth traits(body weight,BW,and body length,BL)based on the restricted maximum likelihood(REML)method.The results show that the heritability of CDH was low(0.12±0.05),while the growth traits(BW and BL)had low to moderate heritability,with 0.20±0.06 for BW and 0.06±0.04 for BL.The phenotypic and genetic correlation between BW and BL was significantly positive,but significantly negative phenotypic and genetic correlations were detected between CDH and BW and between CDH and BL.Furthermore,the analysis of the differences between cold-resistance and phenotypic traits showed that the female reproductive status,exoskeleton hardness and claw number of adult prawns had a great influence on the cold-resistance of M.rosenbergii(P<0.05),indicating that adults with claws and hard exoskeletons are preferred as parents in subsequent breeding selection.The present results can be attributed to the selection and breeding of a new cold-resistant variety of M.rosenbergii.
基金Supported by Special Fund for Agro-scientific Research in the Public Interest(201103034)Huzhou Science and Technology Project(2012GN08,2011ZD2005)Science and Technology Innovation Team Project of Freshwater Aquaculture of Zhejiang Province(2012R10026-11)
文摘A nucleic acid sequence-based amplification(NASBA)assay was established for the detection of Macrobrachium rosenbergii Nodavirus(MrNV).The specific primers were designed according to the high conserved region of RNA2 sequence of MrNV.The 224 bp specific amplification product was obtained in positive sample determined with 3%agarose gel electrophoresis,while no product was generated from shrimp infected with other viruses including DNA viruses(IHHNV,WSSV)and RNA viruses(TSV,IMNV,YHV).The detecting limit of the assay was 8pg nucleic acid,which is more sensitive than that of PCR method.
文摘传染性皮下和造血器官坏死病毒(infectious hypodermal and hematopoietic necrosis virus,IHHNV)是对虾养殖的重要病原之一,可感染多种虾种。罗氏沼虾(Macrobrachium rosenbergii)是中国养殖的重要沼虾品种之一。根据国际兽疫局(Office International des Epizooties,OIE)推荐的IHHNV检测方法,在中国大陆地区首次开展IHHNV在罗氏沼虾中的感染和流行情况调查。结果显示,在研究区的罗氏沼虾养殖区,IHHNV广泛流行,阳性率高达90%;但所有成年罗氏沼虾均未表现出明显的病症,仅表现为病毒的携带。通过基因序列分析显示,检测到的华南地区毒株属于Ⅰ型感染株,与菲律宾株进化关系较为接近;华东地区毒株属于Ⅱ型感染株,与东南亚株进化关系较近。本研究为IHHNV在罗氏沼虾内的感染、流行和防控提供了详细参考。
基金funded by Universiti Malaysia Terengganu and Ministry of Science, Technology and Innovation (MOSTI), Malaysia
文摘In this article, antibiogram and heavy metal resistance profile of bacteria isolated from giant freshwater prawn (Macrobrachium rosenbergii) hatchery in Malaysia are described. Although giant freshwater prawn was introduced into Malaysia since the 1980s, there was no database information on antibiogram and heavy metal resistance profile of bacteria from giant freshwater prawn (M. rosenbergii) hatchery in Malaysia. Therefore, this study was carried out to determine the effectiveness of antibiotic and heavy metal resistance profile to control bacterial diseases in M. rosenbergii hatchery. The results can provide valuable information for local M. rosenbergii post-larval producer. Antibiotic sensitivity test was carried out by disk-diffusion method against 15 types of antibiotics as follows: oxolinic acid (2 μg), ampicillin (10 μg), erythromycin (15 μg), furazolidone (15 μg), lincomycin (15 μg), amoxicillin (25 μg), colistin sulphate (25 μg), doxycycline (30 μg), florfenicol (30 μg), flumequine (30 μg), nalidixic acid (30 μg), tetracycline (30 μg), oleandomycin (15 μg), fosfomycin (50 μg), and spiramycin (100 μg), whereas heavy metal resistance profile of the present bacterial isolates was determined by 2-fold agar dilution technique. In this study, 5 types of bacteria were successfully isolated; they were Aeromonas spp. (n = 77), Escherichia coli (n = 73), Edwardsiella spp. (n = 62), Salmonella spp. (n = 75), and Vibrio spp. (n = 43). The result showed that furazolidone was the most effective antibiotic to control the bacteria isolated in this study, approximately 89.7% of the bacterial isolates were sensitive to this antibiotic. Multiple antibiotic resistance (MAR) index indicated that the hatchery water source and M. rosenbergii post-larval and sediment tanks were at high-risk exposure to the tested antibiotic. Furthermore, all the tested heavy metals (Cd2+, Cr6+, Hg2+, and Cu2+) failed to inhibit the growth of the bacterial isolates. Therefore, it indicated that the water source of the hatchery is contaminated with both antibiotic residues and heavy metal.
文摘There are reports on the use of chemicals like sodium tri polyphosphate (STPP) and foreign materials like pearl tapioca (locally called ‘sagu’), jelly (litchi) to adulterate freshwater prawn (Macrobrachium rosenbergii) prior to freeze processing to increase their weight. Studies were, therefore, undertaken to determine the changes in product quality on the use of different concentrations of STPP, sagu and litchi under ice storage condition. Percent weight gain of prawn was 5.46, 18.87 and 23.50 when dipped in 2%, 4% and 6% STPP solution, respectively. In all cases maximum water uptake by prawn muscle was during the first 6 h with fastest weight gain with STPP solutions containing tap water compared to those of ice and tap water. Organoleptic quality of the STPP treated samples became brown and spongy after 8 h of dipping treatment under iced condition. Quality assessment studies conducted after injecting sagu and litchi in prawn muscle showed little or no difference with those of control samples during the first 6 h, which turned whitish and swollen with severe drip loss after 24 h of ice stored condition, indicating characteristics for easy identification of the injected shrimps by organoleptic method.
基金Supported by a research grant from UPSI(grant No.UPSI2011-0018-102-01)
文摘Objective:To characterize the major allergens of Macrobrachium rosenbergii.(giant freshwater prawn).Methods:Raw and cooked extracts of the giant freshwater prawn were prepared.The IgE reactivity pattern was identified by sodium dodecyl sulfate polyaerylamide gel electrophoresis(SDS-PAGE)and immunoblotting technique with the sera of 20 skin prick test(SPT)positive patients.The major allergen identified was then characterized using the proteomics approach involving a combination of two-dimensional(2-DE)electrophoresis,mass spectrometry and bioinformatics tools.Results:SDS-PAGE of the raw extract showed 23 protein bands(15-250 kDa)but those ranging from 40 to 100 kDa were not found in the cooked extract.From immunoblotting experiments,raw and cooked extracts demonstrated 11 and 5 IgE-binding proteins,respectively,with a molecular mass ranging from 15 to 155 kDa.A heat-resistant 36 kDa protein was identified as the major allergen of both extracts.In addition,a 42 kDa heat-sensitive protein was shown to be a major allergen of the raw extract.The 2-DE gel fractionated the prawn proteins to more than 50 different protein spots.Of these,10 spots showed specific:IgE reactivity with patients'sera.Matrix assisted laser desorption/ionization-lime of flight(MALDI-TOF)analysis led to identification of 2 important allergens,tropomyosin and arginine kinase.Conclusions:It can be concluded that the availability of such allergens would help in component-based diagnosis and therapy of prawn allergies.
