2013年春季,广东佛山养殖的长吻鮠Leiocassis longirostris大范围死亡。从病鱼体内分离到一株病原菌GDFS-01,通过菌落形态观察、革兰氏染色镜检及生理生化鉴定,结合16S r DNA序列测定与系统发育分析,鉴定为鮰爱德华氏菌Edwardsiella ict...2013年春季,广东佛山养殖的长吻鮠Leiocassis longirostris大范围死亡。从病鱼体内分离到一株病原菌GDFS-01,通过菌落形态观察、革兰氏染色镜检及生理生化鉴定,结合16S r DNA序列测定与系统发育分析,鉴定为鮰爱德华氏菌Edwardsiella ictaluri。采取腹部注射和浸泡感染试验均证实该菌有致病性,病症与自然发病症状一致。药敏试验表明:分离菌株对恩诺沙星、氟苯尼考、阿莫西林、洛美沙星、多西环素、磺胺甲基异唑、土霉素等7种药物敏感,对青霉素、氨苄西林、氟哌酸、四环素、万古霉素、利福平、克林霉素等药物呈耐药。本研究结果为长吻鮠病害的有效防控提供参考。展开更多
Edwardsiella ictaluri is known as the etiological agent of Red-head disease of yellow catfish(Pelteobagrus fulvidraco),and is the cause of heavy economic losses in the aquaculture industry.In this study,a DotEnzyme Li...Edwardsiella ictaluri is known as the etiological agent of Red-head disease of yellow catfish(Pelteobagrus fulvidraco),and is the cause of heavy economic losses in the aquaculture industry.In this study,a DotEnzyme Linked Immunosorbent Assay(Dot-ELISA)and an Indirect Fluorescence Antibody technique(IFAT)for detecting Edwardsiella ictaluri were developed by using a monoclonal antibody,5D11.For DotELISA,the working dilutions of 5D11 and the secondary antisera(enzyme-labeled goat anti-mouse Ig)were 1:320 dilution and 1:3000 dilution,respectively.For IFAT,the working dilutions of 5D11 and goatanti-mouse Ig conjugated with fluorescein isothiocyanate were as respectively 1:80 and 1:256.Both of the methods established were highly sensitivity(Minimum detectable concentration,5107 CFU/mL)and had a high degree of accuracy(positive rate was 100%for both artificial infected fish and spontaneous diseased Pelteobagrus fulvidraco).The two reliable methods developed have high potential for quick and efficient detection of Edwardsiella ictaluri in aquaculture production units.展开更多
Mucosal vaccination,which has the potential to induce both mucosal and systemic immune responses,is considered the most suitable method of preventing infectious diseases in farmed fish.Aeromonas veronii and Edwardsiel...Mucosal vaccination,which has the potential to induce both mucosal and systemic immune responses,is considered the most suitable method of preventing infectious diseases in farmed fish.Aeromonas veronii and Edwardsiella ictaluri are two pathogenic bacteria found in yellow catfish and often infect the fish through mucosal surfaces.Delivery of a bivalent inactivated vaccine by injection has been shown to induce a strong systemic immune response against both bacterial infections.However,mucosal immune responses and protective efficiency induced by this inactivated vaccine administrated via immersion are yet to be investigated.We developed a bivalent vaccine containing formalin-inactivated A.veronii and E.ictaluri and evaluated the immune response in yellow catfish after immersion vaccination using body fluids biochemistry indices,agglutinating antibody titers,and the expression level of immune-related genes in the skin,gills,spleen,and head kidney.The activities of innate immune-related enzymes and specific agglutination antibody titers in body fluids,as well as the expression of innate and adaptive immune-related genes in both the mucosal and systemic tissues of vaccinated fish,were significantly higher than that in control fish.Next,we assessed the protective efficacy by a challenge model of virulent strains of E.ictaluri and A.veronii.The relative survival percent of vaccinated fish was 80%and 87%after challenging fish with E.ictaluri and A.veronii,respectively,which was higher than unvaccinated control fish(43%and 57%).These results confirm that the bivalent inactivated vaccine administered via immersion induces a strong mucosal immune response and confers good protection against both E.ictaluri and A.veronii.Our results also reinforce the notion that immersion vaccination could stimulate both mucosal and systemic immunity contributing to protection against pathogens.展开更多
文摘2013年春季,广东佛山养殖的长吻鮠Leiocassis longirostris大范围死亡。从病鱼体内分离到一株病原菌GDFS-01,通过菌落形态观察、革兰氏染色镜检及生理生化鉴定,结合16S r DNA序列测定与系统发育分析,鉴定为鮰爱德华氏菌Edwardsiella ictaluri。采取腹部注射和浸泡感染试验均证实该菌有致病性,病症与自然发病症状一致。药敏试验表明:分离菌株对恩诺沙星、氟苯尼考、阿莫西林、洛美沙星、多西环素、磺胺甲基异唑、土霉素等7种药物敏感,对青霉素、氨苄西林、氟哌酸、四环素、万古霉素、利福平、克林霉素等药物呈耐药。本研究结果为长吻鮠病害的有效防控提供参考。
基金This study was supported by Public Science and Technology Research Funds Projects of Ocean(201405003)Cultivation Plan for Youth Agricultural Science and Technology Innovative Talents of Liaoning Province(2014003)+1 种基金Program of Liaoning Excellent Talents in University(LJQ2011075)to Prof.Qiang Li,General Scientific Research Project of Liaoning Education Department(L2015077)Doctoral Research Program of Liaoning Science and Technology Department(201601287)to Dr.Ruijun Li.
文摘Edwardsiella ictaluri is known as the etiological agent of Red-head disease of yellow catfish(Pelteobagrus fulvidraco),and is the cause of heavy economic losses in the aquaculture industry.In this study,a DotEnzyme Linked Immunosorbent Assay(Dot-ELISA)and an Indirect Fluorescence Antibody technique(IFAT)for detecting Edwardsiella ictaluri were developed by using a monoclonal antibody,5D11.For DotELISA,the working dilutions of 5D11 and the secondary antisera(enzyme-labeled goat anti-mouse Ig)were 1:320 dilution and 1:3000 dilution,respectively.For IFAT,the working dilutions of 5D11 and goatanti-mouse Ig conjugated with fluorescein isothiocyanate were as respectively 1:80 and 1:256.Both of the methods established were highly sensitivity(Minimum detectable concentration,5107 CFU/mL)and had a high degree of accuracy(positive rate was 100%for both artificial infected fish and spontaneous diseased Pelteobagrus fulvidraco).The two reliable methods developed have high potential for quick and efficient detection of Edwardsiella ictaluri in aquaculture production units.
文摘Mucosal vaccination,which has the potential to induce both mucosal and systemic immune responses,is considered the most suitable method of preventing infectious diseases in farmed fish.Aeromonas veronii and Edwardsiella ictaluri are two pathogenic bacteria found in yellow catfish and often infect the fish through mucosal surfaces.Delivery of a bivalent inactivated vaccine by injection has been shown to induce a strong systemic immune response against both bacterial infections.However,mucosal immune responses and protective efficiency induced by this inactivated vaccine administrated via immersion are yet to be investigated.We developed a bivalent vaccine containing formalin-inactivated A.veronii and E.ictaluri and evaluated the immune response in yellow catfish after immersion vaccination using body fluids biochemistry indices,agglutinating antibody titers,and the expression level of immune-related genes in the skin,gills,spleen,and head kidney.The activities of innate immune-related enzymes and specific agglutination antibody titers in body fluids,as well as the expression of innate and adaptive immune-related genes in both the mucosal and systemic tissues of vaccinated fish,were significantly higher than that in control fish.Next,we assessed the protective efficacy by a challenge model of virulent strains of E.ictaluri and A.veronii.The relative survival percent of vaccinated fish was 80%and 87%after challenging fish with E.ictaluri and A.veronii,respectively,which was higher than unvaccinated control fish(43%and 57%).These results confirm that the bivalent inactivated vaccine administered via immersion induces a strong mucosal immune response and confers good protection against both E.ictaluri and A.veronii.Our results also reinforce the notion that immersion vaccination could stimulate both mucosal and systemic immunity contributing to protection against pathogens.
